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Disease Information and Courses from MediaLab, Inc.

These are the MediaLab courses that cover Disease and links to relevant pages within the course.

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Alpha Thalassemia
Defining Thalassemia

Thalassemia is best thought of as a group of disorders rather than a single disease. They demonstrate a hemoglobin synthesis disorder in which there exists a defect in the rate of production of one or more of the globin chains. This defect results from either a heterozygous or homozygous deletion or inactivation of a globin chain gene.

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Alpha Thalassemia States

Heterozygous states of alpha thalassemia express themselves as silent carrier (one loci deleted) thalassemia minor (two loci deleted) hemoglobin H disease (three loci deleted) The homozygous state (all four loci deleted), alpha thalassemia major, is incompatible with life.

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Alpha Thalassemia Intermedia

Alpha thalassemia intermedia (Hemoglobin H Disease) results from a deletion of three out of four alpha chain loci. Infants born with alpha thalassemia intermedia appear normal at birth but often develop anemia and splenomegaly by the end of their first year. Hepatomegaly is not a common finding and there may be some association with mental retardation. Due to the hemolytic nature of this anemia, there may be an increase in respiratory infections, leg ulcers and gallstones. Skeletal changes are not commonly seen in hemoglobin H disease. Every ethnic group can have occurrences of hemoglobin H disease; but it is most often seen in Southeast Asian, the Middle East and the Mediterranean islands. Development and life expectancy are usually normal, but some affected individuals may require splenectomy and transfusion therapy.

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Alpha Thalassemia Minor

Deletion of two out of four alpha chain loci results in alpha thalassemia minor. The deletions may be homozygous (two on the same chromosome) or heterozygous (one from each of two chromosomes). Alpha thalassemia minor does not produce a clinical disease but may be discovered upon routine testing. Both the homozygous and heterozygous form are common in Southeast Asians. The homozygous form is also seen in American Blacks.

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Silent Carrier

The Silent Carrier form of alpha thalassemia results from one alpha chain loci deletion. Individuals who are silent carriers show no clinical disease and demonstrate normal results during routine laboratory testing. This form of alpha thalassemia is usually discovered upon family studies.

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Hemoglobin H disease is found in which ethnic group?View Page
Match alpha thalassemia variants with their genotypic notation.View Page
References

Burtis, CA. & Ashwood, ER. Tietz Textbook of Clinical Chemistry 2nd ed. W. B. Saunders. 1994.Harmening, DM. Clinical Hematology and Fundamentals of Hemostatis 5th ed., F.A. Davis, 2008Lotspeich-Steininger, Stiene-Martin and Koepke, Clinical Hematology Principles, Procedures, Correlations, Lippincott 1992McKenzie, SB., Textbook of Hematology 2nd ed., Williams and Wilkins 1996.Miale, JB, Laboratory Medicine Hematology 6th ed., Mosby 1982.Nouwens, J and Spahn, M. Hemoglobin H Disease: A self-instructional unit 3rd ed., Educational Materials for Health Professionals, Inc. 1991.Doig, K. Rodak's Diagnostic Hematology 3rd ed. W.B.Sunders Co., 2007.

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Summary

The normal RBC count (4.84 x 1012/L) in this case, together with the decreased hemoglobin (8.4 g/dL) and MCV (59 fl) is an indicator of ineffective erythropoeisis that often points to thalassemia.The RBC morphology shows slight hypochromic microcytosis with codocytes, schizocytes, and basophilic stippling. Schizocytes form by several mechanisms, one being the removal of RBC inclusions.This patient's elevated bilirubin correlates with her presentation of sclera icterus; her splenomegaly is consistent with increased RBC destruction.The Hb electrophoresis demonstrated a normal pattern, initially, but the unstable Hemoglobin H was revealed upon repeat electrophoresis with reduced incubation time. Hemoglobin H is the result of beta globin chain tetramer formation due to the insufficient supply of alpha globin chains in alpha thalassemia intermedia.People with Hemoglobin H disease (alpha thalassemia intermedia) usually have a normal life expectancy without treatment. However, hemolysis may lead to moderate anemia that may be treated with splenectomy.

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Serum Iron

The serum iron for normal adults is about 50-150ug/dl.The iron binding capacity is normally 250-400ug/dl.The transferrin saturation is usually between 20-50%Persons with alpha thalassemia, especially Hb H disease, may have a slightly increased level of serum iron with a slightly decreased iron binding capacity. The percent of transferrin saturation is usually increased.An iron stain of bone marrow smears usually demonstrate increased levels of hemosiderin. Sideroblasts are present along with an occasional ringed sideroblast.

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Antibody Detection and Identification
Example of Clinically Significant Immune Antibody

The panel below shows reactions in the AHG phase only (clinically significant). Pattern reactivity of sample matches the pattern displayed by C on the panel. Anti-C is a clinically significant antibody that can cause both hemolytic disease of the newborn (HDN) and hemolytic transfusion reaction (HTR).ND= not done

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Course Introduction

Antibody screening and antibody identification are critical components in blood bank testing. Clinically significant antibodies must be identified so that appropriate blood products are selected for transfusion and the risk of adverse reaction is minimized. Clinically significant antibodies are capable of causing transfusion reactions, hemolytic disease of the newborn and in severe cases, death.This course will discuss the techniques that are used by blood bank technologists to detect and identify various types of antibodies.

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Significance of Reactions at Different Phases of Testing

Antibodies have optimum temperatures for reactivity. Reaction readings can be made at different phases: after immediate spin, after incubation at 37°C, and after the addition of antihuman globulin (AHG) and centrifugation. Reactivity in a certain phase will help to determine whether the antibody is cold reacting (IgM) or warm reacting (IgG). It will also help to distinguish between antibodies that are clinically significant and not significant. Clinically significant antibodies that are capable of causing acute and delayed hemolytic transfusion reactions (HTR) or hemolytic disease of the newborn (HDN) are usually IgG and react best in the AHG phase.Readings can be done at all three phases if a tube method is used. If a gel method is used, readings are done only at AHG. Immediate spin: Antibodies reacting in this phase tend to be cold reactive. They are usually IgM class and not clinically significant (with the exception of the A and B antibodies). 37°: Antibodies that react in this phase include strong IgM or IgG antibodies. After incubation, the tubes are examined for the presence of hemolysis. If complement was bound during incubation then hemolysis could be seen. NOTE: This reaction would only occur in serum samples. If EDTA plasma samples are used for testing, the complement cascade has been halted. Magnesium and calcium ions are not available for complement to be activated. AHG:Antibodies reacting in this phase are considered clinically significant. They are usually warm reactive and IgG.

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Beta Thalassemia
Delta-Beta Thalassemia

Delta-beta thalassemia exists in both heterozygous and homozygous forms. The symptoms are mild to moderate depending on the severity of the disease.This form of beta thalassemia can be found in many ethnic groups, but is most common in persons from Greece and Italy.

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Cerebrospinal Fluid
Clot/Pellicle

Clot formation is always abnormal and is often due to increased levels of protein, especially fibrinogen. When the protein level is 1000 mg/dL, clot formation will most likely occur but clots may also form at lower levels of protein. Some clots may be very fine and appear as a thin membrane or "scum" on the surface of the CSF specimen. This type of clot is referred to as a pellicle. Pellicles are composed of fibrinogen and white blood cells. The type of clot formed may give some specific information about the disease state. Some examples are provided in the following table: Example of ConditionType of Clotbacterial meningitispellicle forms in a short time; large clot formation followsTB meningitisweb-like clot (pellicle) after 12-24 hours (enhanced by refrigeration)paresis (type of neurosyphilis)incomplete clotblockage of CSF circulationcompletely clotted due to protein

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Chemical Screening of Urine by Reagent Strip
Match the following reagent strip tests to the disease or disorder that would most likely cause a positive test result.View Page
Clinical Significance

Urinary urobilinogen may be increased in the presence of a hemolytic process such as hemolytic anemia. It may also be increased with infectious hepatitis, or with cirrhosis. Comparing the urinary bilirubin result with the urobilinogen result may assist in distinguishing between red cell hemolysis, hepatic disease, and biliary obstruction. Urobilinogen is increased in hemolytic disease and urine bilirubin is negative. Urobilinogen is increased in hepatic disease, and urine bilirubin may be positive or negative. Urobilinogen is low with biliary obstruction, and urine bilirubin is positive. Reagent strips methods however, cannot distinguish normal urobilinogen from absent urobilinogen, as might be seen in complete biliary obstruction.

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CLIA Blood Banking Review
Which BBP is not covered in the OSHA Bloodborne Pathogen Standard?View Page
Which of the following antibodies is the most common cause of hemolytic disease of the newborn:View Page
The use of the direct antiglobulin test is indicated in all the following except:View Page
Which of the following conditions is most frequently associated with anti-I:View Page
Which of the following set of conditions would preclude hemolytic disease of the newborn as a result of ABO incompatibility:View Page
Which one of the following statements about directed donations is true:View Page
To detect the presence of blocking antibodies fixed on the red cells of a newborn infant:View Page
Gamma irradiation of cellular blood components is required in which of the following situations:View Page

CLIA Chemistry / Urinalysis Review
Identify the urine sediment elements shown by the arrow:View Page
Identify the urine sediment elements present in this illustration:View Page
Which one of the following crystals is not found in normal urine:View Page
Identify the urine sediment element indicated by the arrow in the illustration:View Page
What type of cast is shown in the illustration:View Page
Identify the urine sediment elements present in this illustration:View Page
Match Increased Analyte with the associated disease:View Page
Which one of the following statements about TSH is true:View Page
Elevation in CSF total protein may be seen in all of the following conditions except:View Page
In a normal CSF the protein concentration as compared to that in the serum is generally:View Page
A spectrophotometric scan of amniotic fluid may be valuable in the determination of which of the following conditions:View Page
Increases in the MB fraction of CK is associated with:View Page
Increases in LD fractions 4 and 5 are indicative of:View Page
The following LDH Isoenzyme pattern would be seen in:View Page
The following LDH Isoenzyme pattern would be seen in:View Page
The following LDH Isoenzyme pattern would be seen in:View Page
The following CK isoenzyme pattern would be seen in:View Page
This SPE scan most likely represents which of the following disease states:View Page
This serum protein electrophoresis scan most likely represents which condition?View Page
Which one of the following are not associated with a polyclonal (broadbased) increase in gamma globulins?View Page
Which of the following conditions is associated with elevated serum uric acid levels:View Page
Which of the following conditions would be suggested by a marked rise in alkaline phosphatase, jaundice, and a moderate rise in ALT:View Page
Which of the following cells when found upon microscopic examination of the urine would be most indicative of kidney disease:View Page

CLIA General Laboratory Review
Which of the following best defines "sensitivity":View Page
Which of the following best defines "specificity":View Page
Which one of the following does not directly regulate clinical laboratories:View Page
Which of the following cells when found upon microscopic examination of the urine would be most indicative of kidney disease:View Page
C-reactive protein:View Page
Which of the following immunoglobulin classes is chiefly responsible for the degranulation of mast cells and basophils:View Page

CLIA Hematology / Hemostasis Review
The abnormal cells seen in this illustration are indicative of:View Page
The abnormal RBCs seen in this illustration are indicative of:View Page
The abnormal RBC shape seen in this illustration is:View Page
The RBCs indicated by the arrows in this illustration are indicative of:View Page
The predominant cells seen in this CSF are suggestive of:View Page
Which two of the following are associated with macrocytic anemia?View Page
Eosinophilia is commonly found in which of the following disorder(s):View Page
Which of the following morphologic changes is most characteristic of sickle cell disease?View Page
Hypersegmentation of granulocytes is most commonly associated with:View Page
Match the disease conditions on the left with appropriate red cell appearances on the right:View Page
Hemophilia A, hemophilia B, and Von Willebrand's disease together constitute approximately what percentage of all hereditary coagulation disorders:View Page
Hemophilia B or Christmas disease is the result of a hereditary deficiency in which coagulation factor:View Page

CLIA Microbiology / Serology Review
Koch's postulates include all of the following except:View Page
Which of the following specimens is the most sensitive for detecting active CMV infection:View Page
Match organism on right to common name on the left.View Page
Match the hepatitis B test with the appropriate disease phaseView Page
Match the virus with its associated disease:View Page
Match the virus with its disease:View Page
Match the virus with its disease:View Page

Confirmatory and Secondary Urinalysis Screening Tests
Diseases Associated with Proteinuria

Normal urine contains very little protein, usually less than 10mg/dL, and the major serum protein that is found in normal urine is albumin. The presence of an increased amount of protein in the urine (proteinuria) can be an indicator of renal disease. The two mechanisms which can lead to proteinuria are glomerular damage or a defect in the reabsorption process of the tubules in the nephron. The concentration of protein in the urine is not necessarily indicative of the severity of renal disease.

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Diseases Associated with Proteinuria

Severe proteinuria (greater than 3.5 g/day) is characteristically seen in patients with glomerulonephritis, lupus nephritis, lipoid nephrosis, and severe venous congestion of the kidney. Moderate proteinuria (0.5-3.5g/day) is seen in nephrosclerosis, multiple myeloma, diabetes nephropathy, malignant hypertension, and pyelonephritis with hypertension. Mild proteinuria (less than 0.5 g/day) may be seen with polycystic kidneys, chronic pyelonephritis, benign orthostatic proteinuria, and some renal tubular diseases. Transient proteinuria can also be due to physiologic conditions such as stress, exercise, cold exposure, and fever, in the absence of renal disease.

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Microalbumin Test

The presence of low levels of albumin (microalbumin) in the urine is an important finding in an individual with either type 1 or type 2 diabetes. The development of clinical nephropathy leads to reduced glomerular filtration and eventually may lead to renal failure. For this reason, early detection of microalbumin is important in order to avert renal complications in a diabetic patient. The presence of microalbuminuria has also been associated with an increased risk for cardiovascular disease. Reagent strips that are used for routine urinalysis cannot detect low levels of albumin excretion (1 to 2 mg/dL). Special reagent strips that are sensitive for these low levels of albumin are useful for periodic monitoring of patients with diabetes, hypertension, or peripheral vascular disease.

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Causes for Bilirubinuria

A screening test for bilirubin in the urine is included in most urine dipsticks and may be present when liver disease or damage is suspected. Bilirubinuria can be detected before other clinical symptoms such as jaundice are present or recognizable. The detection of small quantities is very important in early diagnosis of obstructive and hepatic jaundice. This test is also useful in the differential diagnosis of obstructive jaundice (positive for bilirubinuria) vs. hemolytic jaundice (negative for bilirubinuria).

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The Presence of Glucose in the Urine

The presence of significant amounts of glucose in the urine is called glycosuria (or glucosuria). The amount of glucose present in urine is dependent upon the blood glucose level, the rate of glomerular filtration, and the degree of tubular reabsorption of the sugar. Usually glucose will not be present in the urine until the blood level exceeds 160-189 mg/dl, which is the normal renal threshold for glucose. The main reason for glycosuria is an elevated blood glucose level, called hyperglycemia. Diabetes mellitus is the most common disease that causes hyperglycemia. However, stress, obesity, brain injury, myocardial infarction, hyperthyroidism, pregnancy, and a lowered renal threshold due to kidney damage can all cause glycosuria.

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Current Topics in Clinical Microbiology
Review 2

Smith KR, Fisher HC III, Hook, EW III: Prevalence of fluorescent monoclonal antibody-nonreactive Neisseria gonorrhoeae in five North American sexually transmitted disease clinics.J Clin Microbiol 34:1551-1552, 1996We compared a direct fluorescent monoclonal antibody (DFA) test with alternative enzymatic and fermention tests for identifying presumptive gonococcal isolates in a systematic sample from patients attending five sexually transmitted disease clinics in five cities.Fourteen (2.5%) of 556 isolates from three clinics were nonreactive with the DFA confirmatory reagent and reactive by both the Quad-Ferm and Rapid NH tests. The prevalence of DFA-nonreactive Neisseria gonorrhoeae isolates varies geographically and is independent of local methods for the identification of possible gonococci.On the basis of our findings, we recommend that for use in medicolegal and other instances in which a diagnosis of gonorrhea has the potential to have far-reaching effects, it is appropriate to test DFA reagent-nonreactive, oxidase-positive, gram-negative diplococci by alternative methods of gonococcal confirmation.Although the prevalence of such isolates could change, the fluorescent monoclonal antibody confirmation reagents remain useful for many clinical situations. Their ease of use and ready applicability for screening large numbers of isolates make them useful for many laboratories.

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Acute gonorrhea is the most common cause of septic arthritis in patients under 30 years of age.View Page
Clinical History

A 67 year-old man entered the hospital with cough, right lower chest pain accentuated by deep breathing, and fever. He had a history of chronic obstructive pulmonary disease secondary to a long history of smoking. The temperature on admission was 39.2C, and auscultation of the chest revealed rales in the right lower lung field. The admission white blood count was 13,500/ml with 80% segmented neutrophils and a shift to the left. A blood culture was obtained.

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Clinical isolates of Escherichia coli and Klebsiella pneumoniae may possess ESBL activity. Therefore, clinical laboratories should be screening all clinically significant isolates of these two species.View Page
Review 2

Suppola JP. Kuikka A. Vaara M. Valtonen VV. Comparison of risk factors and outcome in patients with Enterococcus faecalis vs Enterococcus faecium bacteremia. Scandinavian Journal of Infectious Diseases. 30(2):153-7, 1998.The purpose of our study was to determine retrospectively the risk factors for the acquisition of Enterococcus faecalis vs E. faecium bacteremia, as well as the clinical outcomes of these patients.62 patients with Enterococcus faecalis bacteremia were compared to 31 patients with E. faecium bacteremia. Haematologic malignancies, neutropenia, high-risk source and previous use of aminoglycosides, carbapenems, cephalosporins and clindamycin were significantly associated with E. faecium bacteremia. Instead, urinary catheterization was found to be related to Enterococcus faecalis bacteremia. The mortality rates within 7 d and 30 d were 13% and 27%, respectively, in patients with E. faecalis bacteremia and 6% and 29%, respectively, in patients with E. faecium bacteremia.There was no difference in mortality between E. faecalis and E. faecium bacteremia, nor was there a difference in seriousness of disease at the time of bacteremia. In the subgroups of patients with monomicrobial or clinically significant E. faecalis vs E. faecium bacteremia, the mortality rates were similar to the results of all subjects.Our results do not support the theory that E. faecium would be a more virulent organism than E. faecalis

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Each of the following statements is true concerning Clostridium septicum infections except:View Page
Factors predisposing to infections with methicillin resistant Staphylococcus aureus (MRSA) include:View Page
Thus, in follow-up to the previous discussion, the reaction shown in the photograph establishes the identification of a group A, beta hemolytic streptococcus.View Page
Review 1

Spencer RC.: Invasive streptococcEuropean Journal of Clinical Microbiology & Infectious Diseases. 14 Suppl. 1:S26-32, 1995.Before the introduction of antibiotics, serious infections caused by Streptococcus pyogenes (Lancefield Group A streptococci) were common. Before World War II, this bacterium was responsible for as many as 50% of postpartum deaths and was the major cause of death in patients with burns. Also common were the sequelae of streptococcal infections-rheumatic fever and post-streptococcal glomerulonephritis.With the use of penicillin, however, Streptococcus pyogenes was believed to be virtually eliminated as a pathogen. The organism was consigned to the history books, but not for long.In the mid-1980s, focal resurgences of rheumatic fever began to be reported from different areas in the USA, such as Salt Lake City, Utah. In such communities, where increases in cases of rheumatic fever had been reported, the serotypes M-1, 3, 5, 6 and 18 were isolated which, on culture, produced characteristic mucoid colonies. At the same time, reports of increases in invasive streptococcal disease began to surface in both the USA and Europe.Two syndromes were described; invasive streptococcal infection, occurring in previously healthy children and adults, commonly associated with septicaemia resulting from a deep focus of infection such as bone or lung; and streptococcal toxic shock syndrome, involving a cutaneous focus, accompanied by necrotizing or bullous soft tissue changes. Septicaemia is rare in streptococcal toxic shock syndrome, but the most characteristic feature is one of rapidly progressing multi-organ failure. A high proportion of the strains of Streptococcus pyogenes associated with this condition are serotype M-1, and fatality rates approaching 50% have been reported.

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Review 2

Low JC. Donachie W.: A review of Listeria monocytogenes and listeriosis. Veterinary Journal. 153:9-29, 1997Following the initial isolation and description in 1926, Listeria monocytogenes has been shown to be of world-wide prevalence and is associated with serious disease in a wide variety of animals, including man.Our knowledge of this bacterial pathogen and the various forms of listeriosis that it causes has until recently been extremely limited, but recent advances in taxonomy, isolation methods, bacterial typing, molecular biology and cell biology have extended our knowledge. It is an exquisitely adaptable environmental bacterium capable of existing both as an animal pathogen and plant saprophyte with a powerful array of regulated virulence factors.Most cases of listeriosis arise from the ingestion of contaminated food and in the UK the disease is particularly common in ruminants fed on silage.Although a number of forms of listeriosis are easily recognized, such as encephalitis, abortion and septicaemia, the epidemiological aspects and pathogenesis of infection in ruminants remain poorly understood. The invasion of peripheral nerve cells and rapid entry into the brain is postulated as a unique characteristic of its virulence, but relevant and practical disease models are still required to investigate this phenomenon.

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Review 2

Low JC. Donachie W.: A review of Listeria monocytogenes and listeriosis. Veterinary Journal. 153:9-29, 1997Following the initial isolation and description in 1926, Listeria monocytogenes has been shown to be of world-wide prevalence and is associated with serious disease in a wide variety of animals, including man.Our knowledge of this bacterial pathogen and the various forms of listeriosis that it causes has until recently been extremely limited, but recent advances in taxonomy, isolation methods, bacterial typing, molecular biology and cell biology have extended our knowledge. It is an exquisitely adaptable environmental bacterium capable of existing both as an animal pathogen and plant saprophyte with a powerful array of regulated virulence factors.Most cases of listeriosis arise from the ingestion of contaminated food and in the UK the disease is particularly common in ruminants fed on silage.Although a number of forms of listeriosis are easily recognized, such as encephalitis, abortion and septicaemia, the epidemiological aspects and pathogenesis of infection in ruminants remain poorly understood. The invasion of peripheral nerve cells and rapid entry into the brain is postulated as a unique characteristic of its virulence, but relevant and practical disease models are still required to investigate this phenomenon.

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Emerging Cardiovascular Risk Markers
Introduction

We are all aware of the clinical laboratory's role in assessing overall health and we are also aware that measuring a patient's serum lipids will provide some insight into their cardiovascular health. The traditional measurements of low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides are the 'classic' cardiovascular risk markers.Laboratorians, and even the general public are now well-aware that LDL-C ('bad' cholesterol) concentrations should be low while HDL-C ('good' cholesterol) concentrations should be high. Triglycerides should be kept in check as well. Optimal levels are shown in the table below. So what is the risk if these values are not within optimal ranges?Cardiovascular risk can be simply defined as increasing the odds of having a pathology which affects blood flow and/or the heart. The most common cardiovascular pathology is atherosclerosis. Other cardiovascular pathologies whose odds increase as serum lipids and other cardiovascular markers become suboptimal are myocardial infarction (heart attack), stroke, congestive heart disease and coronary artery disease. Other diseases such as diabetes and the metabolic syndrome are also strongly associated with the classic cardiovascular risk markers LDL-C, HDL-C and triglycerides.

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Introduction cont.

The importance of cardiovascular risk markers arises from the fact that cardiovascular disease is the leading cause of death in the United States and that traditional lipid screening protocols often fail to identify high-risk patients. A recent prospective study of nearly 28,000 healthy middle-aged women showed that 77% of cardiovascular events occurred in those with LDL-C values below 160 mg/dL while 46% occurred in those with levels below 130 mg/dL. By using other or additional cardiovascular risk markers we can detect and treat those at risk earlier.

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Risk Markers

We have listed the 'classic' cardiovascular risk markers as LDL-C, HDL-C and triglycerides. But there are many more cardiovascular risk markers as well as cardiovascular risk factors. A cardiovascular risk factor is a condition (not a laboratory analyte) that is associated with an increased risk of developing cardiovascular disease. Examples include: Age Gender (males are at increased risk) Heredity Hypertension Cigarette Smoking Obesity Diabetes StressThere are also negative risk factors, factors which decrease a person's risk of cardiovascular disease. Examples include: Optimal HDL-C concentration Exercise Estrogen Moderate alcohol intakeThis course will not focus on cardiovascular risk factors. Instead we will focus on newer, emerging cardiovascular risk markers. There are well over twenty well-studied cardiovascular risk markers; in this course we will focus on some of the more established markers and the ones which are becoming more commonly measured in the clinical laboratory. These include apolipoprotein A1/apolipoprotein B100, Lp(a), oxidized LDL, LpPLA2, hsCRP and lipoprotein particle size and concentration.It is important to remember that the association between a cardiovascular risk marker and actually having or developing cardiovascular disease is a statistical one. The fact that a patient has a particular risk marker which is abnormal simply increases the probability of developing cardiovascular disease, it does not mean that he or she is certain to develop cardiovascular disease. Conversely, if an individual does not have a particular cardiovascular risk marker present it does not guarantee protection against cardiovascular disease. We must always remember that some percentage of individuals who have heart attacks or strokes will not have abnormal risk markers present.

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Patient Studies to Validate Risk Markers

Risk markers are first hypothesized and then tested. Once a potential marker is identified, concentrations of the serum marker are correlated with patient outcomes. Cardiovascular risk marker studies are typically either retrospective or prospective epidemiology studies. A retrospective study looks backwards at a patient population. For example, we identify (through a hospital database perhaps) patients who have had myocardial infarcts or some other adverse outcome as well as similar subjects without that outcome to use as controls. We then go back and find archived patient serum samples and relate the concentrations of our new risk marker with patient outcomes. Retrospective studies can only be performed if you have archived samples from the patient. Prospective studies look forward in time. For example, we first select a group of subjects and measure our new risk marker in these patients over time. After a few years, we see how the serum concentrations relate to the patient outcomes. Obviously, prospective studies take much longer to perform than retrospective studies. Whatever study model is used, when assessing the value of a cardiovascular risk marker, we must correlate serum concentrations with a specific outcome. The outcome is determined by the study authors. Outcomes could be things like myocardial infarction, stroke, a diagnosis of coronary artery disease, death, or any cardiovascular 'event.'Concentrations of risk markers are divided into tertiles, quatriles or quintiles. This simply means that the top 33%, top 25% or top 20% of the serum concentration values are compared to the bottom 33%, 25% or 20%. For example, risk marker studies will often compare the outcomes of patients with serum concentrations in the upper tertile (those in the top third) with those in the bottom tertile (those in the bottom third) to see if the top 33% had significantly worse outcomes; if so, the risk marker has clinical value.

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Which of the following statements is true?View Page
Importance of Determining Size and Number of Lipoprotein Particles

In the clinical laboratory, we routinely measure the cholesterol content of high-density lipoprotein and low-density lipoprotein particles and not the apolipoproteins on the particles or the number of particles. Proprietary detergents and reagents are used in assays for HDL-C and LDL-C to separate lipoproteins, allowing the cholesterol content of specific lipoproteins to be measured. For example, HDL-C is commonly measured using a solution of dextran sulfate and magnesium to selectively precipitate HDL from the other lipoproteins present in the sample. Once isolated, the HDL particles are 'dissolved' and the amount of cholesterol in them is determined photometrically using a color-producing enzyme reaction. LDL-C can be measured directly or can be estimated using the HDL-C, triglycerides and total cholesterol (TC) values. The Friedewald formula is often used to calculate LDL: LDL-C = TC - (HDL-C)+(Triglycerides/5). The important point to consider here is that traditional LDL-C and HDL-C measurements only tell us how much cholesterol is associated with each lipoprotein particle class. We are now learning that the number and size of the particles are important as well. The number of LDL particles appears to be more strongly predictive of cardiovascular disease than the LDL-C content, and small dense LDL are known to be more atherogenic than larger, less dense LDL particles.

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ApoB/ApoA1: The Test

Measuring ApoB and ApoA1 can be performed using standard immunoassay techniques. Nephelometry is popular, as are ELISA-based methods that are performed on automated chemistry analyzer platforms. The power of the ApoB/ApoA1 ratio as a cardiovascular risk marker is getting widespread attention. An individual with seemingly normal LDL-C may in fact have high ApoB concentrations. When this individual has his or her ApoB/ApoA1 ratio calculated, the risk is evident. Studies have also shown that patients with metabolic syndrome and type-2 diabetes can also easily be identified with the ApoB/ApoA1 ratio, whereas these patients cannot always be identified by measuring LDL-C and HDL-C.In 2004, the global INTERHEART study of risk factors for acute myocardial infarction concluded that the ApoB/ApoA1 ratio was the most important risk factor in all geographic regions. The ApoB/ApoA1 ratio is easy to use because the risk is integrated into a single number that indicates the balance between atherogenic and antiatherogenic particles.There have been many studies concerning the predictive power of the ApoB/ApoA1 ratio. One study, which involved thousands of patients who were followed for an average of 10 years, showed that the ApoB/ApoA1 ratio was a strong predictor of stroke in addition to other cardiovascular events. Due to the evidence presented in studies like these, the National Academy of Clinical Biochemistry (NACB) has recommended that the ApoB/ApoA1 ratio be used as an alternative to the usual total cholesterol (TC)/HDL cholesterol ratio when determining lipoprotein-related risk for cardiovascular disease. Some believe that ApoB/ApoA1 testing will eventually replace traditional LDL-C and HDL-C measurements.

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Lp(a)

Lipoprotein (a) is a modified version of LDL containing a unique protein, apolipoprotein (a). It was discovered in 1963 and is well-associated with vascular disease. Do not confuse apolipoprotein (a) with apolipoprotein A that is found on high density lipoprotein particles. Lipoprotein (a) is abbreviated as Lp(a). Lp(a) is an LDL particle whose ApoB molecule has formed a disulfide bond with another protein called Apo(a), see figure. Apo(a) is a protein very similar in structure to plasminogen. Numerous retrospective case control studies and prospective studies have shown Lp(a) to be an independent risk factor for vascular disease. This means that Lp(a) levels alone (not in conjunction with LDL, or patient risk factors) can predict cardiovascular risk. Lp(a) has been called the most atherogenic lipoprotein. Serum concentrations of Lp(a) are related to genetic factors; drugs and diet changes do not typically lower Lp(a) as they do LDL.

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Adult Treatment Panel

How do physicians interpret risk marker results? Assuming the laboratory offers, and physicians order, cardiovascular risk marker tests, how are these results used? The National Cholesterol Education Program periodically assembles scientists and physicians to create lipid treatment guidelines for patients. These panels are referred to as the Adult Treatment Panel (ATP). The third assembly of the ATP did not give specific guidelines regarding risk marker use in patients but they did acknowledge their potential utility. The general consensus is that novel cardiovascular risk markers should be used in selected patients, such as those who already have significant risk factors (hypertension, smoking, obesity, etc.) or in patients who have family histories of cardiovascular disease. The value in using risk markers is that they will not only uncover cardiovascular risk but they can also be used to motivate patients to alter lifestyle and diet. It is expected that as these emerging cardiovascular risk markers continue to be validated in clinical studies, they will become very useful and perhaps even be part of a new standard of care for patients.If risk marker levels can be correlated to treatment strategies, physicians will find them especially useful in tracking patient success.

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High Sensitivity-C-Reactive Protein

C-reactive protein (CRP) is a very sensitive acute phase reactant. Serum CRP levels increase following a variety of pro-inflammatory events such as infection, tissue necrosis, trauma, surgery and even malignancy. CRP levels can increase quickly and dramatically (often 100 fold) during inflammation. CRP can activate compliment, bind Fc receptors and can function as an opsonin, enhancing phagocytosis with certain infections. Measurement of CRP is not new, it has been on clinical laboratory testing menus for decades. However, a newer version of the CRP test is now in use to assess cardiovascular risk.High sensitivity-CRP (hs-CRP) assays have been developed that are more sensitive to the more subtle changes that can occur during chronic vascular inflammation. (Recall that atherosclerosis is an inflammatory process.) By measuring hsCRP we can get a glimpse at vascular function. CRP has been shown to be an independent risk factor for atherosclerotic disease and cardiac death. A 2002 prospective study of more than 27,000 patients showed that the CRP concentration is a stronger predictor of cardiovascular events than the LDL-cholesterol level.

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The hs-CRP Test

The traditional CRP test has a typical reference range of < 8 mg/dL. The hs-CRP test, with its increased sensitivity has a reference or optimal range of < 3 mg/dL. As with most risk markers, the results of hs-CRP testing are generally interpreted on a relative scale; the higher the value, the higher the risk of a future cardiovascular event.The American Heart Association and Centers for Disease Control and Prevention has defined risk groups with hs-CRP as follows: Low risk: < 1.0 mg/L Average risk: 1.0 to 3.0 mg/L High risk: > 3.0 mg/L It is important to note that hs-CRP assays are measuring the same protein as traditional CRP assays. Thus, in patients with active inflammation (such as chronic, active arthritis; lupus; infection; etc.) hs-CRP values would be expected to be high and would not necessarily implicate cardiovascular risk. If values greater than 10 mg/L are seen in repeated measurements, a non-cardiovascular cause should be considered. Taking anti-inflammatory drugs (NSAIDs, aspirin, etc.) or the statin-class of cholesterol-lowering drugs may reduce CRP levels in patients. This is not an artifact, but is thought to be an effect of treating the underlying inflammatory process.

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References

Atherosclerosis. U.S. Department of Health & Human Services National Institutes of Health. Available at http://www.nhlbi.nih.gov/health/dci/Diseases/Atherosclerosis/Atherosclerosis_WhatIs.htmlAccessed June 23, 2009.Daniels LB, Barrett-Connor E, Sarno M, Laughlin GA,Bettencourt R, Wolfert RL. Lipoprotein-associated phospholipase A2 (Lp-PLA2) independently predicts incident coronary heart disease (CHD) in an apparently healthy older population: The Rancho Bernardo study. J Am Coll Cardiol. 2008;51:913-919.Executive Summary of the third report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III). JAMA. 2001; 285:2486-2497. Frostegard, J, Wu R, Lemne C, Thulin T, Witztum JL and de Faire U. Circulating oxidized low-density lipoprotein is increased in hypertension, Clin Sci 2003; 105, 615.Garza CA, Montoir VM, McConnell JP, et al. Association between lipoprotein-associated phospholipase A2 and cardiovascular disease: a systematic review. Mayo Clin Proc. 2007;82(2):159-165.Interpretive Handbook, (MC0440rev0407) Mayo Clinic, Rochester MN;2007. Maksimowicz-McKinnon K, Bhatt DL, Calabrese LH: Recent advances in vascular inflammation: C-reactive protein and other inflammatory biomarkers. Curr Opin Rheumatol. 2004;16:18-24.Mora S, Szklo M, Otvos JD, et al. LDL particle subclasses, LDL particle size, and carotid atherosclerosis in the multi-ethnic study of atherosclerosis. Atherosclerosis. 2007;192:211-217.NACB Laboratory Medicine Practice Guidelines. Emerging biomarkers of cardiovascular disease and stroke. National Academy of Clinical Biochemistry Laboratory Medicine Practice Guidelines. 2006.PLACtest animation, diaDexus. http://www.plactest.com/laboratorians/action.php Accessed June 23, 2009.Rifai N, Warnick GR. Lipids, lipoproteins, apolipoproteins, and other cardiovascular risk factors. In: Burtis CA, Ashwood ER. Bruns DE. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 4th ed. St. Louis, MO: Elsevier Saunders: 2006; chap. 26.Ridker PM, Rifai N, Rose L, et al. Comparison of C-reactive protein and low-density lipoprotein cholesterol levels in the prediction of first cardiovascular events. N Engl J Med. 2002;347:1557-1565.Sniderman AD. Differential response of cholesterol and particle measures of atherogenic lipoproteins to LDL-lowering therapy: Implications for clinical practice. J Clin Lipidol 2008;2:36-42.Tsimikas, S, Brilakis ES, Miller ER, et al. Oxidized phospholipids, Lp(a) lipoprotein, and coronary artery disease, N Engl J Med: 2005;353:46.Tsimikas S, Bergmark C, Beyer RW, et al. Temporal increases in plasma markers of oxidized low-density lipoprotein strongly reflect the presence of acute coronary syndromes. J Am Coll Cardiol. 2003; 41: 360.Tsimikas, S, Lau HK, Han KR, et al. Percutaneous coronary intervention results in acute increases in oxidized phospholipids and lipoprotein(a): Short-term and long-term immunologic responses to oxidized low-density lipoprotein. Circulation. 2004;109, 3164.Tsimikas S, Witztum JL, Miller ER, Sasiela WJ, et al. High-dose atorvastatin reduces total plasma levels of oxidized phospholipids and immune complexes present on apolipoprotein B-100 in patients with acute coronary syndromes in the MIRACL trial, Circulation: 2004;110, 1406. Walldius G, Jungner I, Holme I, et al. High apolipoprotein B, low apolipoprotein A-I, and improvement in the prediction of fatal myocardial infarction (AMORIS study): a prospective study. Lancet. 2001;358:2026-2033.Yusuf S, Hawken S, Ounpuu S, et al. Effect of potentially modifiable risk factors associated with myocardial infarction in 52 countries (the INTERHEART study): case-control study. Lancet. 2004;364:937-952.

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LpPLA2 and Cardiovascular Risk

There have been dozens of clinical studies demonstrating LpPLA2's ability to predict cardiovascular risk. A 2008 study showed that people whose LpPLA2 concentrations were in the upper quartile were 1.64 times more likely to have a cardiac event than those in the lowest quartile. A meta-analysis (a study that sums the results of several other studies) performed by researchers at the Mayo Clinic showed that the unadjusted odds ratio for the association between elevated Lp-PLA2 levels and cardiovascular disease risk was 1.51, indicating that patients with elevated LpPLA2 patients had 1.51 times the risk of cardiovascular disease or events.

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Size and Number

Although lipoproteins of a particular class are generally within a given size range, there are many biochemical processes that interact with lipoproteins to alter their size, density, and lipid composition. When low-density lipoprotein (LDL) becomes smaller and denser, it is more likely to interact with the arterial wall, leading to deposition of cholesterol and initiating or worsening atherosclerosis. Research has shown that high numbers of smaller, denser LDL are more atherogenic than larger, lighter LDL particles. Small, dense LDL particles are associated with more than a three-fold increase in the risk of coronary heart disease.

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Erythrocyte Inclusions - Wright Stained Smears
The presence of erythrocyte inclusions may indicate the presence of disease.View Page

Fundamentals of Hemostasis
The product administered to treat Von Willebrands Disease is?View Page
An Introduction to the Fundamentals of Coagulation

As we will discover later in the course, there are other variables which impact the effectiveness of hemostatic mechanisms as well, such as acquired disease states, and inborn metabolic pathway defects. For now, however, our focus will be on the mechanisms, processes, and components which work together to achieve coagulation, or the cessation of blood flow from a damaged vessel. Note: The terms coagulation and hemostasis are used interchangeably throughout this course.

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Tests of Hemostatic Function - Platelet Function Assay

A platelet function assay (PFA) is a screening test for the evaluation of platelets/primary hemostasis. Common clinical applications include the following: Preoperative evaluation of platelet function Determining the presence of drug-induced platelet dysfunction Determining platelet functionality in high-risk pregnancy Evaluation of patients with suspected inherited or acquired platelet disorders such as von Willebrand disease Evaluation of a bleeding patientA PFA instrument is able to differentiate between drug-induced platelet defects and other platelet defects. PFA tests are superior to the bleeding time test. The bleeding time is often not reproducible and, in spite of attempts at standardization, remains prone to variations in test results between persons performing the test. It is also relatively insensitive to platelet function. The bleeding time cannot be used to identify patients who may have recently ingested aspirin or non-steroidal anti-inflammatory drugs or patients who may have a platelet defect attributable to these drugs. The bleeding time is used to assess platelet function, but may be affected by platelet quantity. NOTE: Aspirin, and some other drugs, may falsely prolong bleeding times. Patients must be asked about aspirin use, and be aspirin free for 7-10 days prior to testing, for valid results.

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Coagulation Disorders

This course began with a discussion on homeostasis, the body’s desire to maintain a status of physiological equilibrium. Our inborn system of chemical checks and balances, activators and inhibitors, can be disrupted by numerous factors, two of the more common being acquired disease states and disorders passed on to offspring via inheritance. In regard to coagulation, both disease status and genetics can adversely affect the functionality of many hemostatic processes. Impaired hemostatic mechanisms, be it acquired in cases of disease or inherent, may result in situations of either hemorrhage or thrombosis. A situation of hemorrhage, or bleeding external to the vasculature, most often stems from physical vessel trauma, but may also arise from a wide variety of disease states. Thrombosis does not require physical trauma, and is the activation of hemostatic processes at an inappropriate time in an inappropriate place, and may arise from a number of inherited or acquired disease states. The following pages are intended to serve as an introduction to some of the more commonly encountered coagulation disorders.

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Coagulation Disorders - Inherited

Von Willebrands Disease is a platelet disorder. This disorder is characterized by a functional defect in Von Willebrands factor (vWF) itself. This disease often clinically manifests with a concurrent deficiency of factor VIII, but will present with a normal platelet count. As far as genetics and inheritance, both men and women are affected equally. Von Willebrands factor is essential for platelet binding, therefore, a defect in vWF causes impaired platelet adhesion and aggregation. The treatment of Von Willebrands Disease involves the administration cryoprecipitate, as it is rich in vWF.

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Coagulation Disorders - Acquired

Disseminated Intravascular Coagulation (DIC) is best described as a disorder of consumption, because clotting factors are depleted from the blood. Basically, clotting occurs randomly throughout the body, as opposed to just in the localized areas where vascular damage has occurred, consuming clotting factors and other components such as platelets in the process. Symptoms may range from a mild bleed, to severe, profuse bleeding, primarily dependant upon the availability of clotting factors. As more and more coagulation factors and components are consumed, the disorder progresses and symptoms worsen. Most heavily impacted are the levels of factors I, V, and VIII as well as the number of available platelets. Clinically, DIC is detected via an elevated (positive) FDP, positive D-dimer test, a prolonged PT and APTT, plus the manifestation of hemorrhagic episodes. DIC is diagnosed as two primary types, acute and chronic. Acute DIC manifests in a few hours or a few days, has a high mortality rate, and is seen in infections, obstetric complications, liver disease, and tissue injury. Chronic DIC is a secondary condition to some other disease state. Once you treat the primary disease, this type of DIC will go away. Treatment is often factor replacement therapy through the use of fresh frozen plasma and/or cryoprecipitate.

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Coagulation Disorders and Liver Disease

The liver is the site of production for the vast majority of our clotting factors. Therefore, impaired liver function could adversely affect these hemostatic proteins. Some early indicators of a potential liver problem include: An increase in factor VIII. It is not produced in the liver and will be present in elevated numbers as the body attempts to compensate. The PT is sensitive to liver function, so an unexpected, prolonged PT should be evaluated. A lack of fibrinogen is often indicative of severe liver disease. It is difficult to treat liver disease, so therapy typically centers around replacing the missing factors by way of administration of fresh frozen plasma.

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Which of the following statements regarding coagulation disorders is incorrect?View Page

Fundamentals of Molecular Diagnostics
Targets

Molecular based clinical diagnostic test methodologies differ according to the target of interest. For example, patients suspected of having different diseases will require the identification of different targets. These targets might be found in different cells of the body and may therefore require different specimens to provide the answers. Patient A suspected of having Disease 1-requires the identification of a target of missequenced DNA- might require specimen of whole blood Patient B suspected of having Disease 2-requires identification of a target of antibody production-methodology might require specimen of serum Using this specific approach of disease diagnosis based on unique target identification, tests can provide answers that are more rapid sensitive specific

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Overview

To aid in the diagnosis of disease or identification of infectious agents, clinical laboratorians use a variety of methodologies to assist them. Knowing what to look for, or the right question to ask, is vital to obtaining the correct answer. Many diseases and agents have unique causes. The cause of the condition then becomes the "target" to be identified and perhaps even quantified. For example: If Patient A is suspected of having disease X, and disease X requires treatment, it is necessary to prove that disease X exists within patient A. We must know something about what causes disease X; is disease X an antigen, a bacteria, a viral particle, a missequenced piece of DNA?Once the target of interest (in this case Disease X) has been identified, the clinical laboratorian can choose the methodology most appropriate to answering the question, "Does disease X exist within Patient A?"

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Human Genome

Much research has been conducted to identify the alphabet of the human cellular language otherwise known as the human genome. This identification or roadmap of the human genetic material has opened the door to the mainstreaming of molecular diagnostics within the clinical laboratory setting.While the mapping of the human genome project is complete, many times it is not necessary to be able to identify the entire sequence; rather, we can use the specific portion of the code that is unique to the disease or condition in question. These short portions of the genetic molecular sequence or oligonucleotides, can then be used as probes to seek out and detect or amplify the target sequence.

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When Nucleic Acids Get Altered

The reason to chose a particular molecular method can be influenced by disease detection, monitoring or therapy in certain patient populations. Molecular methodologies can be used to identify alterations or variations or changes in DNA sequencing that can cause disease. Sequence alterations that are known to cause disease are termed mutations. These changes or mutations can be applied to areas of the clinical lab such as infectious disease, paternity, genetic testing, and pharmacogenetics. Some of the more common alterations are:Deletion: a missing nucleotide or other portion of DNA sequence Insertion: an extra DNA nucleotide or other portion of DNA sequence Missense: a nucleotide or sequence substitution that codes for a different amino acidNonsense: a nucleotide substitution that ends in early termination of the protein manufacturing process; usually due to a stop codon.The most common alteration is a single base change or single nucleotide polymorphism (SNP)

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Hereditary Hemochromatosis
References

1. Beutler E. Iron storage disease: Facts, fiction and progress. Blood Cells Mol Dis. 2007;39:140-7.2. Higgins T, Beutler E, Doumas BT. Hemoglobin, iron, and bilirubin. In: Burtis CA, editor. Teitz Fundamentals of Clinical Chemistry. 6th ed. Saunders Elsevier, 2008.3. Ganz T. Hepcidin, a key regulator of iron metabolism and mediator of anemia and inflammation. Blood 2003;102(3):78-8.4. Andrews NC, Schmidt PJ. Iron homeostasis. Annu Rev Physiolo. 2007;69:69-85.5. Murtagh LJ, Whiley M, Wilson S, et al. Unsaturated iron binding capacity and transferrin saturation are equally reliable in detection of HFE hemochromatosis. Am J Gastroenterol. 2002;97(8):2093-9.6. Haddy TB, Castro OL, Rana SR. Hereditary hemochromatosis in children, adolescents, and young adults. Am J Pediatr Hematol Oncol 1988;10:23-4.7. Edwards CQ, Ajoika RS, Kushner JP. Hemochromatosis: A genetic definition. In Barton JC, Edwards CQ, eds. Hemochromatosis: Genetics, Pathophysiology, Diagnosis and Treatment. Cambridge, UK:Cambridge Univ Pr 2000:8-11.8. Whitlock EP, Garlitz BA, Harris EL , et al. Screening for Hereditary Hemochromatosis: A Systematic Review for the U.S. Preventive Services Task Force. Ann Intern Med. 2006; 145: 209-23.9. Wallace DF, Subramaniam VN. Non-HFE haemaochromatosis. World J Gastroenterol. 2007;13(35):4690-8.10. Tavill AS. Diagnosis and management of hemochromatosis. Hepatology. 2001;33:1321-811. Qaseem A, Aronson M, Fitterman N, Snow V, Weiss KB, Owens DK, et al. Screening for hereditary hemochromatosis: a clinical practice guideline from the American College of Physicians. Ann Intern Med. 2005;143:517-21.12. Phatak PD, Bonkovsky HL, and Kowdley KV. Hereditary Hemochromatosis: time for targeted screening. Ann Intern Med. 2008; 149(4): 270 – 2.13. Brissot P, deBels F. Current approaches to the management of hemochromatosis. Hematology Am Soc Hematol Educ Program. 2006:36-41. 14. Guidance for industry: Variances for blood collection from individuals with hereditary hemochromatosis. http://www.fda.gov/cber/gdlns/hemchrom.htm Accessed 12/17/08.

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Overview

Because hereditary hemochromatosis (HH) is a disease of iron overload, a review of the basic principles of iron metabolism is helpful in understanding its pathophysiology. Iron is needed by all body cells and is crucial for oxygen transport, oxidative metabolism, and cell growth and proliferation. To serve these functions, iron must be bound to protein. Iron is potentially harmful when ionized or complexed to inorganic compounds. Iron must be present in amounts sufficient to carry out these normal functions, but not in excessive amounts which may be toxic.Two types of iron-containing compounds are normally found in the body: compounds that serve in metabolic or enzymatic functions and storage compounds. Hemoglobin, myoglobin, cytochromes and other proteins are involved in oxygen transport and utilization. Iron in hemoglobin comprises about 67% of total body iron, thus erythrocytes are rich in iron. Approximately 27% of iron is found in storage compounds. Myoglobin, other tissue iron, and transport iron comprise the remaining 6% of total body iron. (2)

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Incomplete Penetrance

For reasons as yet unknown, not all individuals who are homozygous for the C282Y mutation display phenotypic features of HH, and persons with H63D polymorphisms rarely develop iron overload. The penetrance (percentage of individuals with a specific genotype who express the associated phenotype) of HFE mutations is generally considered to be low. Results of a recent meta analysis by the US Preventive Services Task Force conclude that 38% to 50% of all C282Y homozygotes develop some evidence of iron overload, but that only 10% to 33% develop clinical disease due to HH. (8) In other words, some individuals may have elevated iron test results such as transferrin saturation, but do not demonstrate significant organ damage. Estimates of penetrance in some studies have found it to be even lower. Penetrance of HFE mutations is currently a controversial subject among experts, and the significance of finding HFE mutations in a given individual is often unclear. The probability that a given individual with HFE mutations will develop clinical disease from iron overload cannot be determined at this time.

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General Clinical Considerations

Hereditary hemochromatosis (HH) is frequently discovered only during management of associated illness or routine health evaluations. It has been estimated that only a small percentage of all affected persons are actually diagnosed. Individuals with HH may be symptomatic for several years prior to diagnosis and may have consulted multiple health care providers.Under-diagnosis of HH is thought to occur due to:• Lack of specificity of early signs and symptoms• Asymptomatic status of some patients until damage to organs and tissues has occurred• Confusion with liver disease due to other causes• Insufficient awareness and knowledge of HHEarly identification of persons with HH is essential to prevent serious and irreversible complications associated with severe iron overload. A classic triad of skin hyperpigmentation (bronzing), type 2 diabetes, and hepatic cirrhosis has long been recognized as evidence of advanced iron overload. However, persons with HH may present with a much wider variety of signs and symptoms, particularly if they are seen before significant iron accumulation has occurred. Age of presentation and disease severity are highly variable. A diagnosis of HH is based on laboratory evidence of iron overload, genetic mutations associated with HH, and presence of clinical signs and symptoms consistent with HH.(10)

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Which of the following does NOT contribute to the under-diagnosis of hereditary hemochromatosis (HH)?View Page
Secondary Disorders of Iron Overload

In addition to hereditary hemochromatosis (HH), there are other conditions of iron overload that must be considered in a differential diagnosis. Disorders such as sickle cell disease, thalassemia, sideroblastic anemia, congenital dyserythropoietic anemia, and liver disease may also cause iron overload. Transfusion-dependant patients and persons who abuse iron-containing vitamin supplements are also at risk. These conditions are usually described as secondary iron overload, in contrast to the primary iron overload of HH.Patient history, clinical signs and symptoms, biochemical and hematologic laboratory analyses, and possibly results of a liver biopsy may be needed to establish a diagnosis of a condition causing secondary iron overload. DNA tests for common HFE mutations are very likely the most important diagnostic tool for identifying HH as the cause of iron overload. In some patients, both secondary causes and HH may be contributing to iron overload. Differentiating the secondary causes of iron overload from HH is heavily dependent on the results of laboratory assays, but a complete discussion is beyond the scope of this course.

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Which of the following is NOT considered to be a cause of secondary iron overload?View Page
Transferrin Saturation

Transferrin saturation (TS) is usually reported along with the SI and TIBC. TS indicates the percent of iron binding sites on transferrin that are carrying iron. TS is derived from a calculation using the formula:TS =(SI/TIBC) x 100TS results are reported as percentages. Typical reference intervals for TS are 20% to 55% for males and 15% to 50% for females. TS is generally considered to be the most sensitive laboratory test for detecting altered iron metabolism in hereditary hemochromatosis (HH). It may be elevated prior to significant deposition of tissue iron. TS levels increase as additional iron is accumulated.A drawback to using the TS is that it is dependent on performing both the SI and TIBC. The UIBC (see section below) may be a lower cost alternative.The optimal TS criterion for detecting HH is controversial. Using a TS of >60% for males and >50% for females has been found highly accurate in detecting abnormal iron metabolism in persons with HH. Others studies suggest using lower TS levels, e.g. 45%, as a criterion indicating further testing is warranted. Current guidelines from the American College of Physicians include a TS cutoff level of >55% for identifying iron overload. (11)Patients with initially increased TS should be followed by performing a second TS from a fasting morning specimen. The patient should also be advised not to take vitamins supplemented with iron or oral contraceptives for several days prior to the repeated test. TS levels may be affected by diurnal variation, dietary factors, and co-existing disease states such as inflammation and hepatitis. Patients with HH may have falsely normal TS if chronic blood loss or inflammatory disease is present.

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Serum Ferritin

Serum ferritin (SF) level reflects the amount of storage iron in tissues. An elevated SF combined with elevated TS implies primary iron overload. Patients with hereditary hemochromatosis (HH) generally show increases in SF as adults, but a normal SF does not rule out the diagnosis of the disease. Children and premenopausal females with HFE mutations may have had inadequate time to develop iron overload, but may do so later in life.SF alone is inadequate as the sole screening test for HH because it lacks the necessary sensitivity and specificity. SF is frequently elevated in persons with inflammation, cancer, or infection. SF is often ordered along with the serum iron and TIBC when iron overload is suspected. SF is also important is assessing the efficacy of treatment of HH.Upper limits of reference intervals for SF are 200 ng/mL for premenopausal women and 300 ng/mL for men and postmenopausal women. 40 ng/mL is a typical lower limit for the reference interval.SF is measured in serum using immunochemical methods such as enzyme-linked immunosorbent assay (ELISA), immunoradiometric assay, immunochemiluminescent assay, and immunofluorometry. SF tests are available as automated assays and in kit form.(2)

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Screening Controversies

The subject of screening for hereditary hemochromatosis (HH) is controversial and is currently being debated in the medical literature. Using laboratory tests to screen the asymptomatic general population is currently not recommended due to issues of testing costs, low genetic penetrance, and the possible risk of discrimination. Targeted case finding in select high risk populations such as men of Northern European ancestry may be a better approach to screening. (12)Molecular-based (DNA) assays required for confirmation of HH are costly when used for general population screening. Because recent studies have shown that a high percentage of persons with C282Y mutations do not develop iron overload or HH-related clinical conditions, screening for these mutations may falsely label an individual with a disease diagnosis. At the present time, it is impossible to determine which homozygotes or heterozygotes for HFE mutations will eventually develop iron overload. Furthermore, there is potential risk of discrimination in obtaining health insurance for persons identified as having genetic disorders.In contrast, some experts do advocate for screening the general population. Mutations associated with HH are very common in Caucasians in the US. Individuals who know they carry mutations associated with HH may benefit from periodic testing for iron overload. Finally, laboratory tests that assess iron status are relatively inexpensive, widely available, and offer one approach to screening for phenotypic expression of HH. Screening first-degree family members of a person with documented HH is generally considered to be worthwhile. Early detection of HH in relatives with common mutations may permit treatment before the development of substantial iron overload and related disease due to organ damage.

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Molecular Tests

DNA tests for HFE mutations associated with hereditary hemochromatosis (HH) are available in some clinical laboratories and reference laboratories. Testing for the presence of the C282Y is essential, although most labs also test for H63D and S65C mutations. Molecular testing is most appropriate for confirmatory testing of symptomatic individuals with altered iron studies (increased TS and SF), in pre-symptomatic individuals (increased TS, normal SF and liver function tests), and in family members of individuals diagnosed with HH. The use of genetic tests alone for routine screening of asymptomatic persons is not recommended for several reasons. A positive test indicating the presence of HFE mutations does not guarantee that an individual will develop clinically significant iron overload or predict severity of symptoms. A negative result (no HFE mutations present) does not rule out a diagnosis of iron overload because of genetic heterogeneity. Compared to biochemical analyses for iron, molecular assays are expensive. Finally, molecular testing may result in the diagnosis of a genetic disease, thus opening up the possibility for discrimination in health insurance coverage. Using molecular methods, DNA is extracted from leukocytes in whole blood samples or from buccal cells and analyzed for specific HFE mutations using polymerase chain reaction (PCR) with melt curve analysis. Currently there are no FDA-cleared products for HFE testing, and testing laboratories are using "home brew" reagents. This situation is expected to change as manufacturers submit products for FDA approval.

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Definitive Tests for Iron Overload

Measuring the amount of iron deposited in the liver is considered definitive for iron overload. This may be done by liver biopsy, computed tomography (CT), or magnetic resonance imaging (MRI). Demonstrating iron in parenchymal liver cells helps determine disease severity. Liver sections obtained by biopsy are stained with Perls Prussian blue which stains iron present in parenchymal cells. A photomicrograph of this reaction is shown.Although liver biopsy may not be necessary for diagnosing hereditary hemochromatosis (HH), it offers the advantage of detecting liver fibrosis if present. Molecular tests for mutations associated with HH are considered the gold standard of current HH testing. Liver biopsy is not needed for diagnosing all patients suspected of having HH, but may be ordered in some cases.

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Other Treatments

Deferoxamine (DFO), an iron chelating agent, may be used to reduce iron overload in patients for whom phlebotomy is contraindicated or not well tolerated. Examples include patients with sickle cell disease or thalassemia whose anemia would be exacerbated by phlebotomies. DFO is seldom used to treat hereditary hemochromatosis (HH) due to the low cost and efficacy of phlebotomy therapy. DFO is typically administered by intravenous or subcutaneous infusion.Patients with HH may be counseled to avoid alcohol use in order to avoid liver damage. With the exception of iron supplements, dietary restrictions on iron ingestion are rarely advised.

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Which of the following is NOT a cause of death in patients with hereditary hemochromatosis (HH)?View Page

HIPAA Privacy and Security Regulations
Case Study: Authorization You are working in a physicians office. The doctor orders laboratory and other diagnostic tests on a patient with suspected Alzheimer's disease. He then asks you to give the patient's name and contact information to the local Alzheimer support group without getting permission from the patient or his legal guardian. Does the doctor need authorization from the patient or his legal guardian to do this?View Page

HIV Safety for Florida
A person commits a misdemeanor of the first degree by:View Page
Risk factors associated with increased HIV infection

The risk factors that increase the risk of an exposure leading to HIV infection are: larger quantity of blood from source person, and blood from source person in terminal stage of HIV disease.

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Confidentiality

A person who receives the results of an HIV test shall maintain the confidentiality of the information received and of the person tested.A person who violates the confidentiality provisions commits a misdemeanor of the first degree.A person who obtains information that identifies an individual who has a sexually transmissible disease and maliciously, or for monetary gain, disseminates this information commits a felony of the third degree.

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Introduction to Bioterrorism
Category B

Agents in Category B are considered the second highest priority agents and are included in this group because they: Are moderately easy to disseminate Cause moderate morbidity and low mortality Require specific enhancements of Centers for Disease Control and Prevention’s (CDC) diagnostic capacity and enhanced disease surveillance

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Agent: Pneumonic plague (Bacterium)

Most likely means of dissemination: AerosolPrimary route of entry: InhalationGeneral signs and symptoms: High fever, chills, headache, coughing up of blood (hemoptysis), and toxemia, progressing rapidly to difficulty in breathing (dyspnea), and bluish discoloration of the skin and mucous membranes (cyanosis).There is another form of the disease called “bubonic plague”. While it is caused by the same organism, it is not transmissible through human contact. Pneumonic plague is transmissible through human contact.

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Agent: Tularemia (bacterium)

Most likely means of dissemination: Solid or aerosolPrimary route of entry: Inhalation, absorption, or ingestionGeneral signs and symptoms: Sudden fever, chills, headaches, muscle aches, joint pain, dry cough, progressive weakness, and pneumonia.The disease is not transmissible through human contact.  When used as a WMD, infection would be acquired by handling infected material, eating or drinking contaminated food or water or by breathing in the bacterium.

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Laboratory Response

The broad base of clinical laboratories in this country is an essential component of our nation’s public health and healthcare system and is an essential link in addressing biological and chemical terrorism. In 1999 the Centers for Disease Control and Prevention (CDC) initiated the concept of a Laboratory Response Network (LRN).  The LRN is a network of local, state, federal, and military laboratories across the United States and internationally which work together in an integrated and coordinated way for a rapid response to public health emergencies. The LRN concept of operations is based on a system of safety and proficiency.

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What if: Biological Attack

Biological attacks involve bacteria, viruses or natural toxins. The effects of toxins can be immediate but for bacteria and viruses the effects may not be apparent for weeks. A bio-terrorist may attack by infecting animals, contaminating food and water, spraying bacteria or viruses into the air. In infections such as smallpox and plague, once a few individuals are infected they can further spread the disease from person to person. An attack could also come from through a building’s ventilation system, the mail, or even through exposure to an infected terrorist seeking to spread disease during an infectious stage.

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In Case of a Biological Attack

Listen to the radio for instructions from authorities on whether to evacuate or stay put. If told to stay inside, seek shelter in an internal room or a room with as few doors and windows as possible. Turn off all ventilation and as best as possible seal all openings in windows and doors. Continue to monitor the radio. Some biological attacks may be more immediately apparent than others. Monitor your radio, television, or medical alert for instructions from authorities regarding disease symptoms and how and where to seek medical attention. If you do come in contact with a visible, potentially infectious substance, you should remove and bag your clothes and personal items, wash yourself with warm soapy water immediately, and seek medical assistance.

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Additional Information

Below is additional information that you can obtain off the internet to help you “Be Prepared”.www.ready.gov: This site has emergency preparedness guidance from the United States Dept. of Homeland Security. It also has an excellent training program for kids.www.redcross.org: Preparedness information from the International Red Cross.www.neighborhoodpreparedness.info: From the Los Angeles Fire Department. www.americaswaterwaywatch.org: Prepared by the United States Coast Guard. Discusses what to look for as far as suspicious activities.www.bt.cdc.gov: Discusses agents, disease, and other threats.www.ojp.usdoj.gov: The Citizens’ Preparedness Guide provides suggestions for preparedness in homes, neighborhoods, and schools.www.fema.gov/areyouready: FEMA’s most comprehensive source on individual, family, and  community preparedness.

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Introduction to Bone Marrow
Collection of Bone Marrow Biopsy

A bone marrow biopsy involves removing a small portion of the bone marrow without destroying the architecture of the marrow. This type of biopsy is necessary when the marrow cannot be aspirated (dry tap) due to a disease process, and also provides additional information complementary to that derived from the aspirate: biopsy specimens are more accurate for assessing cellularity, and infiltrative processes, such as metastatic carcinoma, fibrosis, amyloid, and lymphoma. A biopsy specimen is processed as follows: touch preparation tissue section

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Gaucher Cell

A Gaucher cell is a histiocyte (macrophage) whose cytoplasm is filled with linear or fibrillar material (kerasin). This cell is characteristic of the congenital glycolipid disorder, Gaucher's disease. Gaucher cells may also be seen in the marrow of patients with chronic granulocytic leukemia. When seen in this condition, they are referred to as pseudo-Gaucher cells.

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After Marrow Evaluation

After the marrow is evaluated, the diagnosis is established and extent of the disease is determined. Follow up bone marrow examinations may be needed to monitor changes in the marrow following treatment or when signs and symptoms of relapse occur. To summarize, a bone marrow examination can provide valuable information to aid in the diagnosis of a variety of disorders. Due to the expense involved and the discomfort to the patient, clear indications of need should be present before this examination is undertaken.

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Examples of Conditions

Examples of conditions in which examination of the bone marrow may provide diagnostic information include:Erythrocyte Disordersanemiamegaloblasticsideroblasticiron deficiencyerythrocytosispolycythemia veraLeukocyte DisordersneutropenialeukemialymphomaPlatelet DisordersthrombocytopeniathrombocytosisMiscellaneous Disordersprotein abnormalitiesmultiple myelomaWaldenstrom's Macroglobulinemiadiseases of the RE systemhypersplenismmetastatic carcinomagranulomatous infectionsstorage diseasesGaucher's diseaseNiemann-Pick disease

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Introduction to the ABO Blood Group System
Immunoglobulin

The predominant immunoglobulin class for the B antibodies produced by individuals with group A phenotype and the A antibodies produced by individuals with group B phenotype is IgM. Small quantities of IgG may also be present. IgG is the predominant immunoglobulin for the anti-A and anti-B antibodies found in individuals with group O phenotype. Infants of group O mothers are at higher risk for hemolytic disease of the newborn (HDN) than those born to mothers with group A or B because IgG immunoglobulins readily cross the placenta. IgM molecules do not readily cross the placenta because of their larger size. It is important to note that immune antibodies are usually IgG. Both naturally occurring and immune ABO antibodies are critically important in transfusion since both sensitize and usually hemolyze red cells with the corresponding antigen.

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Laboratory Ergonomics
References

Centers for Disease Control and Prevention. Laboratory ergonomics. Available at: http://www.cdc.gov/od/ohs/Ergonomics/labergo.htm. Accessed July 6, 2009.Cornell University. CUErgo. Available at: http://ergo.human.cornell.edu/ Accessed July 6, 2009.National Institute for Occupational Safety and Health. Ergonomics and musculoskeletal disorders. Available at: http://www.cdc.gov/niosh/topics/ergonomics/ Accessed July 6, 2009.UCLA Ergonomics. Musculoskeletal disorders: Anatomy of an injury. Available at: http://ergonomics.ucla.edu/MSD_Anatomy.html. Accessed July 6, 2009.US Department of Labor. Healthcare wide hazards module: Ergonomics. Available at: http://www.osha.gov/SLTC/etools/hospital/hazards/ergo/ergo.html Accessed July 6, 2009.

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Posture and Exercises

Being aware of your posture is important for prevention of MSDs. These are postures that should be avoided: Prolonged or repetitive bending at the waist Prolonged standing or sitting without shifting position Keeping an arm outstretched for a prolonged period of time Holding or turning your head consistently to one side Remaining in an awkward position for a prolonged period of timeThe Centers for Disease Control and Prevention (CDC) recommends several exercises that are beneficial for the prevention of MSDs. The exercises are included as a resource in this course. They can also be accessed at http://www.cdc.gov/od/ohs/pdffiles/exercises.pdf(last access July 3, 2009).

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Laws and Rules of the Florida Board of Clinical Laboratory Personnel
Description of Specialties (3)

Specialists in radioassay use radionuclides to determine the chemical makeup of body fluids such as blood and urine. Specialists in blood gas analysis evaluate lung and breathing function by levels of oxygen, carbon dioxide, pH, and hemoglobin with automated tests. Specialists in histology examine cellular and tissue samples using fixation, dehydration, embedding, microtomy, frozen sectioning, staining, and other similar techniques. Histology specialists licensed as technicians can perform specimen processing, embedding, cutting, staining, and frozen sectioning only under the general supervision of a director, supervisor, or technologist. Specialists in cytology process and interpret samples relating cytopathological disease. Non-gynecological cytology preparations can be screen by a specialist in cytology but final review and interpretation must be done by a physician.

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Description of Specialties (4)

Specialists in cytogenetics detect chromosome abnormalities and genetic disorders. Cytogenetics counseling may only be performed by an individual licenses in the cytogenetics specialty at the director level. Specialists in molecular genetics analyze DNA and RNA to find disease-related genotypes, mutations, and phenotypes in order to detect or predict disease and identify carriers. Specialists in histocompatibility test to determine tissue compatibility, prevent infections, and investigate and post-transplant problems. Techniques include blood typing, HLA typing, HLA antibody screening, disease markers, flow cytometry, crossmatching, HLA antibody identification, lymphocyte immunophenotyping, immunosuppressive drug assays, allogenic, isogeneic and autologous bone marrow processing and storage, mixed lymphocyte culture, stem cell culture, cell mediated assays, and assays for the presence of cytokines. Specialists in andrology and embryology examine gametes and embryos, including production, morphology, number, and motility, to address issues of fertility and infertility.

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Medicare Compliance for Clinical Laboratories
Billing and medical necessity

Billing: Highest risk activity a laboratory has. All laboratory activities contribute to the billing process. Many of the risk areas included in this program are components of the billing function. Medical necessity: Medicare is only allowed, by law, to pay for tests that are reasonable and necessary for the diagnosis and treatment of disease. Medical necessity is an underlying principle of the Medicare program. Tests performed for screening or routine exams are not considered medically necessary by the Medicare program.

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Coding

CPT (Current Procedural Terminology) codes are used to describe specific tests or services. The amount of payment for a test is dependent on the CPT code. It is against the law to use the wrong CPT code for a test for the purpose of causing or increasing payment for a test. ICD-9CM (International Classification of Disease, 9th Edition, Clinical Modification) codes are used to classify diseases and conditions, and describe signs, symptoms and medical circumstances. ICD-9CM codes are used to indicate the medical necessity of a particular test. It is against the law to use the wrong ICD-9CM code for the purpose of causing or increasing payment for a test.

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Medical coverage policies (LMRPs)

LMRPs (Local Medical Review Policies) are published by Medicare for some laboratory tests. Developed for tests that can be used for screening or diagnosis of disease. CPT codes describe laboratory tests and ICD-9CM codes determine when coverage is allowed. If an LMRP test is ordered by a physician, an ICD-9CM code that is included in the LMRP must be given to the laboratory or the Medicare program will not pay for the test. It is against the law for laboratory to change or add an ICD-9 code submitted by a physician. The Balanced Budget Act of 1997 made it illegal for physicians to order LMRP tests and not supply an ICD-9CM code with the order.

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Medical necessity

Medical necessity means that Medicare is not allowed by law to pay for any tests that are not necessary for diagnosis or treatment of disease.A laboratory may not submit a claim to Medicare or other government payers for any test it knows is not medically necessary except in certain cases: When the patient has signed an advance notice. When a patient has requested the lab to submit such a claim for a determination by Medicare. Medicare does not pay for screening tests or tests that are ordered in the absence of signs or symptoms.Billing department employees are responsible to follow all policies and procedures related to the submission of claims to reduce erroneous billings.

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ICD-9CM coding

ICD-9CM (International Classification of Disease, 9th Edition, Clinical Modification) codes are used for the classification of disease and conditions and for describing signs, symptoms and medical circumstances.These codes are used to indicate the medical necessity of a particular test.ICD-9 codes can only be supplied by the ordering physician or a representative of that physician. "Code steering" means to steer or direct a physician to supply an ICD-9 code that is payable. ICD-9 codes cannot be used from a previous laboratory order. If a physician supplies a narrative description instead of an ICD-9 code the laboratory must accurately translate that code using only certified coders.It is against the law to use the wrong ICD-9 code for the purpose of causing or increasing payment for a test.

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Local medical review policies (LMRPs)

LMRPs (Local Medical Review Policies) are published by Medicare for some laboratory tests. They are usually developed for tests that can be used for screening or diagnosis of disease. LMRPs use CPT codes to identify the tests and ICD-9 codes to determine when coverage is allowed. If an LMRP test is ordered by a physician, an ICD-9 code that is included in the LMRP must be given to the laboratory or the Medicare program will not pay for the test. It is against the law for laboratory to change or add an ICD-9 code submitted by a physician. A laboratory should not submit a claim for an LMRP test that is not accompanied by an acceptable ICD-9 code. The Balanced Budget Act of 1997 made it illegal for physicians to order LMRP tests and not supply an ICD-9CM code with the order.

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Medicare Compliance for Clinical Laboratories (updated 2009)
ICD-9CM coding

ICD-9CM (International Classification of Disease, 9th Edition, Clinical Modification) codes are used for the classification of diseases and conditions, and for describing signs, symptoms and medical circumstances. These codes are used to indicate the medical necessity of a particular test. All employees who are directly or indirectly responsible for reporting to Medicare must be aware of these guidelines to prevent fraudulent claims: ICD-9 codes can only be supplied by the ordering physician or a representative of that physician. ICD-9 codes cannot be used from a previous laboratory order. If a physician supplies a narrative description instead of an ICD-9 code the laboratory must accurately translate that code using only certified coders. It is against the law to use the wrong ICD-9 code for the purpose of causing or increasing payment for a test.

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Local medical review policies (LMRPs)

Local Medical Review Policies (LMRPs) are published by Medicare for some laboratory tests. They are usually developed for tests that can be used for screening or diagnosis of disease. LMRPs use CPT codes to identify the tests and ICD-9 codes to determine when coverage is allowed. If an LMRP test is ordered by a physician, an ICD-9 code that is included in the LMRP must be given to the laboratory or the Medicare program will not pay for the test. It is against the law for a laboratory to change or add an ICD-9 code submitted by a physician. A laboratory should not submit a claim for an LMRP test that is not accompanied by an acceptable ICD-9 code. The Balanced Budget Act of 1997 made it illegal for physicians to order LMRP tests and not supply an ICD-9CM code with the order.

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Medical necessity

The Centers for Medicare and Medicaid Services (CMS), the US agency that administers the Medicare program, defines "medical necessity" as services or items reasonable and necessary for the diagnosis or treatment of illness or injury or to improve the functioning of a malformed body member. Medicare will not pay for any tests that CMS determines as unnecessary for diagnosis or treatment of disease.A laboratory may not submit a claim to Medicare or other government payers for any test it suspects is not medically necessary unless: The patient has signed an Advanced Beneficiary Notice, or A patient has requested the lab to submit such a claim for a determination by Medicare. Medicare does not pay for screening tests or tests that are ordered in the absence of signs or symptoms. Billing department employees are responsible for following all policies and procedures related to the submission of claims to reduce erroneous billings.

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Mycology: Hyaline and Dematiaceous Fungi
Match each of the names of the fungi listed in the left column with its most likely associated disease listed in the right column.View Page
The fungus illustrated in this photomicrograph was recovered from an induced sputum specimen from a 74 year old man with chronic obstructive pulmonary disease. This isolate is most likely:View Page
Match the name of each dematiaceous fungus listed in the drop-down box with its most likely disease.View Page
The disease with which the dematiaceous fungus illustrated in this photomicrograph is most likely associated is:View Page

Mycology: Yeasts and Dimorphic Pathogens
Match each of the names of the dimorphic fungi listed with the names of the animals that most commonly may be related to transmission of disease to humans.View Page
Match the names of each of the diseases listed with its appropriate situation:View Page
Each of the following dimorphic fungal infections have been observed in animals living in their natural environment except:View Page
Which of the following fungal infections was once known as "Chicago disease" because so many cases had occurred in the Chicago area?View Page
Match the complications that are most likely to be associated with each of the two yeast diseases that are listed in the drop-down box:View Page
The growth of the yeast-like colonies shown in the upper image was obtained on blood agar from a skin culture only in the area overlaid by virgin olive oil. The lower image is a photomicrograph of a lactophenol blue mount made from a portion of the colony. The disease associated with this fungus is:View Page
Although only a few human cases have been reported, brewers and bakers may in particular be at increased risk for developing infections with:View Page
Of the following responses, the one observation that would rule out cryptococcosis as the cause of meningoencephalitis is:View Page

Normal Peripheral Blood Cells
Definition of a Segmented Cell continued.

Since these recommendations have been adopted by many groups, including the College of American Pathologists and the Centers for Disease Control, we will be using them as our criteria for differentiating between bands and segs.This definition was first reported by the Committee for Clarification of the Nomenclature of Cells and Diseases of the Blood and Blood Forming Organs, in the American Journal of Clinical Pathology (18:443-450, 1948).

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OSHA Bloodborne Pathogens (updated October 2008)
Standard Precautions!

Standard precautions mean that all blood and body fluids should be handled as if they were infectious and capable of transmitting disease. Standard Precautions apply to all: Blood Body fluids Secretions (except sweat) Excretions Non-intact skin Mucous membranes

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What happens after HIV infection?

Days to weeks after exposure, the patient may begin to complain of fever, headache and fatigue. This may also be accompanied by a rash.For the first several months after the infection, the exposed individual maybe HIV antibody negative - this is called a "window" period.The disease may remain silent in the patient for months to years even with no treatment.At some point in time, when the immune system is weakened enough, the patient will develop opportunistic infections and be classified as having AIDS (acquired immunodeficiency syndrome).

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HCV disease

Like HBV disease, HCV disease results in damage to the liver. About 75% of individuals who are infected with HCV go on to develop chronic hepatitis C. Patients with chronic hepatitis C may eventually develop scarring of the liver (known as cirrhosis) and liver failure.

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Hepatitis C treatments

There is no known cure for HCV disease. Some patients may require long-term therapy with a medication called Interferon.If patients develop liver failure due to HCV infection, they may require a liver transplant.

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Packaging and Shipping Infectious Materials
Classifications of Hazardous Materials

The US Department of Transportation (DOT) classifies hazardous materials according to the risks that they pose. There are nine hazard classes: Class 1: Explosives Class 2: Gases Class 3: Flammable liquids Class 4: Flammable solids Class 5: Oxidizers/organic peroxides Class 6: Toxic and infectious substances Class 7: Radioactive material Class 8: Corrosives Class 9: Miscellaneous hazardous materials Within class 6 are two divisions: Division 6.1- poisonous material Division 6.2- infectious substanceA division 6.2 infectious substance is defined as a material known or reasonably expected to contain a pathogen. A pathogen is a microorganism or other agent (e.g., a prion) that can cause disease in humans or animals. The regulations that govern packaging and shipping a class 9, miscellaneous hazardous material, may also need to be reviewed by those who package and ship laboratory specimens. Dry ice is a class 9 hazardous material and, if used, requires special packaging, and specific labeling and marking on the outer package.

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Categories of Division 6.2 Infectious Substances

Hazardous material classifications are consistent across all agencies who regulate commercial shipping and are based on criteria developed by the United Nations (UN) Committee of Experts working with the World Health Organization (WHO), the Centers for Disease Control and Prevention (CDC), medical professionals, microbiologists, transportation professionals, and packaging technical experts. These requirements can be found in the 13th and 14th editions of the United Nations Recommendations for the Transport of Dangerous Goods, the 2005 - 2006 edition of the International Civil Aviation Organization Technical Instructions for the Safe Transport of Dangerous Goods by Air (ICAO Technical Instructions), and the International Maritime Organization (IMO) Dangerous Goods Code. The classification system for Division 6.2 Infectious Substances includes two catergories, known simply as Category A and Category B.

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Category A Definition and Examples

A category A infectious substance is in a form that is capable of causing permanent disability or life-threatening or fatal disease in otherwise healthy humans or animals when exposure to it occurs. Exposure would occur if the substance were released from its protective packaging and a human or animal came into contact with it. Some examples of category A infectious substances include: Bacillus anthracis (cultures only) Brucella abortus (cultures only) Brucella melitensis (cultures only) Burkholderia mallei (cultures only) Clostridium botulinum (cultures only) Dengue virus (cultures only) Escherichia coli, verotoxigenic (cultures only) Ebola virus Francisella tularensis (cultures only) Hantaviruses causing hemorrhagic fever with renal syndrome Herpes B virus (cultures only) Human immunodeficiency virus (cultures only) Lassa virus Mycobacterium tuberculosis (cultures only) Poliovirus (cultures only) Rabies and other lyssaviruses (culture only) Shigella dysenteriae type I (cultures only) West Nile virus (cultures only) Yersinia pestis (cultures only)This is not an exhaustive list. Sometimes, deciding on the classification of an infectious substance requires professional judgement and involves knowing the medical history or symptoms of the source patient or animal and/or knowing the local epidemiological conditions at the time the patient specimen or culture was obtained. If there is doubt as to whether or not a substance meets the criteria of category A, it must be treated as a category A substance for shipping.

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Category B Definition, Shipping Name, and Identification Number

A category B infectious substance is not in a form generally capable of causing permanent disability or life-threatening or fatal disease in otherwise healthy humans or animals when exposure to it occurs. The proper shipping name and Identification number is:Biological substance, Category B, UN 3373

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Exempt Substances

Laboratory specimens that are unlikely to cause disease and do not meet the criteria for category A or B substances are not subject to Division 6.2 regulations. Specimens for which the hazardous materials regulation (HMR) does not apply include human or animal samples (including, but not limited to, secreta, excreta, blood and its components, tissue and tissue fluids, and body parts) being transported for routine testing not related to the diagnosis of an infectious disease. This includes specimens that are being sent for: drug or alcohol testing cholesterol testing blood glucose level testing prostate specific antibody (PSA) testing testing to monitor kidney or liver function pregnancy testing tests for diagnosis of non-infectious diseases such as cancer biopsies

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Definitions

Before further discussion of Category A and Category B, it is important to define two additional terms that are used in the classification process. CultureAn infectious substance containing a pathogen that is intentionally propagated, for example a bacterium grown on bacteriological medium as seen in the image below. Culture does not include a human or animal patient specimen.Patient specimenHuman or animal materials collected directly from humans or animals and transported for research, diagnosis, investigational acitivities, or disease treatment or prevention. Patient specimen includes excreta, secreta, blood and its components, tissue and tissue swabs, body parts, and specimens in transport media (e.g., transwabs, culture media, and blood culture bottles).* *It is important to note that this means specimens that have been collected into these transport media, but have not yet been incubated and are not actively growing in the media.

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Security Awareness

A category A infectious substance is in a form that is capable of causing permanent disability or life-threatening or fatal disease in otherwise healthy humans or animals when exposure to it occurs. Exposure would occur if the substance were released from its protective packaging and a human or animal came into contact with it. Therefore, it is critical that a category A infectious substance does not end up in the hands of an unauthorized individual who may purposely or unknowingly release the substance from its protective packaging and endanger humans or animals. Being aware of the people that you interact with in the process of packaging and sending category A substances is vital to the safety of the transport and prevention of a health disaster. An outsider with limited access and system knowledge could constitute a threat, but be aware that insiders could also be a threat, e.g., a disgruntled employee or a person who is angry with his or her supervisor or job or the government. Anyone desiring to do harm could potentially seize the opportunity to steal a hazardous material.Follow these precautionary procedures: When you are questioned about an infectious substance that you are packaging for shipment, it is important that you know the person that is asking AND that he or she has a need to know. If you do not know the person and if you are not aware that the person needs to know about the substance that is being shipped, do not answer the questions. You could refer him or her to your supervisor. Watch for unusual behavior. Secure the package until it is picked up. Check the identification of the courier who will be picking up the package. Use an intralaboratory chain of custody procedure if the specimens are tranferred within the facility or system. Track the package once it has been sent to be sure it arrives safely. Notify the Responsible Official or federal authority if the package does not arrive at its destination.

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Security Plan for Category A Infectious Substances

Each facility that stores and transports hazardous materials must have a written, detailed security plan. The Select Agents and Toxins Security Information Document that was prepared by the Centers for Disease Control and Prevention (CDC) and the U.S. Department of Agriculture, Animal and Plant Health Inspection Service (APHIS) is an excellent resource to use for developing a security plan that would apply to category A infectious substances. This document can be found at http://www.selectagents.gov/resources%5CSecurity%20Information%20Document.pdfThe current version, dated March 8, 2007, is available in this course as a resource. However, because the document does undergo revisions, it is recommended that the URL given above be checked periodically for document updates.

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Parasitology Review
A 32 year old male was seen in the emergency room with gastrointestinal discomfort. Upon questioning the patient it was learned that he first began feeling ill after spending a day at the park where he swam and played volleyball barefooted. He first noticed a lesion on his foot. Later, he developed vague respiratory symptoms. Now his largest complaint is severe abdominal pain along with occasional vomiting. This patient is most likely suffering from:View Page
This stool parasite measures 55 µm by 50 µm and is the causative agent of:View Page
The suspicious form pictured here is responsible for which of the following conditions?View Page
This suspicious form, recovered in stool, measures 12 µm in length. Which of the following conditions is this form responsible for causing when present?View Page
A 68-year-old female, who recently vacationed in Brazil, presented to her physician exhibiting overall weakness, fever, and enlarged lymph nodes. Blood was collected for culture and parasitic examination. The culture was negative. This suspicious form was recovered upon examining the Giemsa-stained preparation. This patient is most likely suffering from:View Page
Match each pictured parasite with its corresponding associated condition:View Page
Protozoal parasites that typically do not produce disease in humans are referred to as being:View Page
A 31 year old male missionary worker recently returned from Africa where he helped a small rural community update their sanitation practices. He presented to his physician weak and complained of recent weight loss, abdominal pain, and diarrhea that was often bloody. The doctor ordered a battery of tests including a complete blood count (CBC) and stool for parasite examination. The CBC revealed eosinophilia and anemia. This suspicious form was seen on the wet preparations. It measured 52 µm by 27 µm. What parasite is mostly likely present?View Page
A 58 year old male, who recently returned from an extensive overseas business trip to Africa, presented to the local clinic complaining of nausea, vomiting, and an achy feeling all over his body. At first he thought it was just the flu, but it persisted. The doctor ordered a battery of tests including blood smears for parasitic study. This suspicious form was recovered. The patient is most likely suffering from:View Page
A 45 year old mother of two went to her physician because her children were recently diagnosed with ascariasis and she was concerned that she had also contracted the disease. Other than complaining of recent sporadic diarrhea, she was in overall good health. The doctor ordered a stool for ova & parasite examination. This suspicious form, measuring 55 µm was seen throughout the sample. This form is most likely:View Page
Xenodiagnosis has historically been used to identify:View Page
What term is defined as the presence of arthropods in or upon a human host:View Page

Pharmacology in the Clinical Lab: Therapeutic Drug Monitoring and Pharmacogenomics
Unexpected Concentrations

TDM provides a quantitative measure of the circulating concentration of a drug. The physician determines if the dosage of the drug needs to be adjusted based on this information.If a drug concentration is determined to be outside the therapeutic range, it may be for one of the reasons listed in the table below. Reason Discussion Noncompliance Patients may (intentionally or unintentionally) not take the drug. TDM can thus help monitor compliance. Dosing errors The dose may have been erroneous or inappropriate given the patient's condition. Malabsorption The TDM result will reveal if the drug cannot be absorbed well through the gut and an alternative route of administration will be needed. Drug interactions Many drugs interfere with the absorption or metabolism of other drugs. These interactions will be revealed by TDM. Kidney or liver disease Any pathology that affects elimination will cause an elevation in a drug level that will be unmasked by TDM. Altered protein binding Changes in serum proteins can lead to big changes in the amount of free drug in serum. Variations in the genetics of drug-metabolizing enzymes can also affect drug concentrations in the body. This is the field of pharmacogenomics that will be discussed later in the course.

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TDM for Theophylline

Theophylline is used as a bronchodilator for treatment of moderate to severe asthma and chronic obstructive pulmonary disease (COPD). TDM is needed for theophylline because the kinetics of the drug are highly variable. It has a narrow therapeutic window, and overdose can result in elevated heart rate, arrhythmia, and CNS excitability. Clearance of the drug is increased in children, smokers, persons with cystic fibrosis, and persons with hyperthyroidism. Elimination is slowed in congestive heart failure and in the elderly.

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Protein Availability and Drug Dosing

Drug-binding proteins in serum can fluctuate in disease states. For example, if albumin levels fall, as can occur in liver failure or nephrotic syndrome, less albumin will be available for drug binding; a subsequent dose may produce a toxic concentration of free drug.The image on the right illustrates the loss of equilibrium between a protein-bound drug and a free drug when drug-binding proteins are diminished.Doses of drugs that are highly protein-bound may need to be adjusted in patients with lower drug-binding protein levels. Examples of some common drugs that are highly protein-bound include thyroxine, warfarin, diazepam, heparin, imipramine and phenytoin. �

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Warfarin cont.

The genes involved in warfarin metabolism are CYP2C9 and vitamin K epoxide reductase complex subunit 1 (VKOR). Warfarin owes its anticoagulant action to its inhibition of VKOR. This enzyme recycles vitamin K, a critical element for the clotting factors II, VII, IX, and X, as well as for proteins C, S, and Z. There are six CYP2C9 alleles that are known to cause prolonged metabolism of warfarin: CYP2C9 *2, *3, *4, *5, *6, and *11. (Polymorphisms in CYP450 genes are denoted with asterisks.)One-third of the patients that receive warfarin metabolize it differently than expected and experience a higher risk of bleeding.Genetic testing for the two most common polymorphisms (CYP2C9*2 and *3) as well as for VKOR may be able to reduce the variability associated with warfarin dosing response. Labs performing PGx testing can provide general warfarin dosing recommendations based on the patient's genotype analysis. The lab report will indicate whether a patient has a normal, mild, moderate, high, or very high sensitivity to warfarin. For example, a patient who has one CYP2C9 normal wild-type allele (CYP2C9 *1), one polymorphism (CYP2C9*3), and also a VKOR polymorphism is predicted to have a moderate sensitivity to warfarin. This patient should have frequent INR monitoring and possible warfarin dose reduction. It is important to recognize that knowing a genotype does not necessarily guarantee accurate dose prediction; other drugs and/or environmental or disease factors can also alter CYP2C9 activity. Therefore, monitoring the INR is still very important.

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Phlebotomy
Plasma lipids

Lipids are fats dispersed in plasma. They include: Triglycerides Cholesterol Lipoproteins The amount and ratios of various lipids in the blood will determine a person’s risk of getting coronary artery disease.

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Quality Control
Calculating Sensitivity

Sensitivity is the ability of a test to correctly identify individuals who do have a particular disease or disorder. To determine sensitivity, we use the following equation: True Positives (TP) Divided by True Positives (TP) plus False Negatives (FN) Times 100 or (TP ÷ (TP + FN)) x 100 The result will be a percentage.

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Specificity vs. Sensitivity

To review, specificity is “disease focused”. The more specific a test is, the fewer false positive results will occur. Remember that a false positive result can possibly lead to a misdiagnosis with the possible consequence of unnecessary diagnostic procedures and therapies. Sensitivity, on the other hand, is “wellness or normal focused”. The more sensitive a test is, the fewer false negative results it produces.

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Verification of Performance Specifications for Nonwaived Testing

On April 24, 2003, the Clinical Laboratory Improvement Amendments (CLIA) Final Rules went into effect.As of that date, each laboratory that introduces a nonwaived, unmodified, FDA-cleared or approved test system must do the following before reporting patient test results: Demonstrate that it can obtain performance specifications comparable to those established by the manufacturer for the following performance characteristics: Accuracy. Precision. Reportable range of test results for the test system. Verify that the manufacturer's reference intervals (normal values) are appropriate for the laboratory's patient population.

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Reading Gram Stained Direct Smears
Cellular elements

The Gram stain reaction and appearance can be used to identify most cellular material seen in a direct smear. Identification of cellular elements present in a direct clinical smear is important because most of these elements play an important role in the disease process. For example, the quality of a sputum sample can be assessed by determining the relative numbers of squamous epithelial cells and polymorphonuclear leukocytes (segmented neutrophils) present.

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Red Cell Disorders: Peripheral Blood Clues to Nonneoplastic Conditions
Note the view of a peripheral blood smear in the photograph. Pictured are scattered acanthocytes, echinocytes, target cells, spherocytes, and schistocytes. The condition in which each of these atypical RBC's may be found in varying numbers in the same peripheral blood smear is:View Page
An 8 year old girl is protected from severe hemolytic anemia by an elevated fetal hemoglobin level ( hemoglobin F).View Page
The nucleated red blood cell and myelocyte photographed here were found on scanning of a peripheral blood smear. In context they are suggestive of metastatic carcinoma to the bone marrow.View Page
The erythrocyte at the tip of the arrow is an echinocycte (burr cell).View Page
The peripheral blood picture is consistent with each of the following conditions except:View Page
Leukoerythroblastosis

Illustrated in this field is a normoblast and a myelocyte, representing leukoerythroblastosis, a term associated with the release of immature cells from a disrupted marrow. Metastatic disease in the bone marrow, particularly in patients with primary breast or prostate cancer, is usually the culprit. Leukoerythroblastosis in the absence of anemia or thrombocytopenia is a signal to search for cancer metastic to the marrow. Nucleated RBCs were not identified on the blood smear seen here but were detected by an automated analyzer.The mortality rate of elderly patients with increased NRBCs, especially following accidents or general surgery, is greater.

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Schistocytes vs. bite cells

Schistocyte is a general term for a fragmented red blood cell that may assume various shapes, some with horn-like projections (keratocytes), triangle-forms (triangulocytes), and helmet shapes, as illustrated in the upper photograph. Schistocytes are formed when erythrocytes are forced through a vessel blocked with interlacing fibrin strands and the red cells are sliced into fragments. True schistocytes are devoid of central pallor. These damaged cells continue to circulate while healing their torn edges. Finally, they are removed by the spleen. Bite cells (lower photograph) appear when an abnormal hemoglobin aggregate (Heinz body) is nibbled out of a red cell's cytoplasm by the spleen leaving a bitten apple appearance. Glucose 6-PD deficiency secondary to chemical poisoning or injury by oxidant drugs are settings for Heinz body formation, and the telltale bite cells remain as evidence. Hemolytic anemia associated with severe liver disease is another setting where bite cells are formed.

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DIC: graft vs. host disease

The peripheral smear illustrated in the photograph was obtained from a patient with a recent renal transplant. The patient developed a rash, accompanied by nausea and diarrhea. Graft vs. host disease was clinically suspected. The peripheral smear findings are consistent with that diagnosis. The presence of spherocytes suggests a hemolytic process which is supported by the presence of nucleated RBCs. A few scattered schistocytes and the decrease of platelets suggests DIC. The presence of target cells presents the possibility of associated liver disease. Additional tests, particularly coagulation studies, should confirm the diagnosis of microangiopathic hemolytic anemia.

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Hemolytic disease of the newborn

Jaundice was recognized in a day-old infant. Notice particularly the size variation (anisocytosis) of the erythrocytes on the infant's peripheral smear. What does this observation mean? Does it provide immediate information that might serve as guidance in expediting diagnosis and treatment? Note that normal-sized red blood cells, microcytes, microspherocytes, macrocytes, and nucleated red blood cells are all present. Red cell variations are expected findings in healthy neonates, but the variations here are exaggerated. Hyposplenic functional features may appear, including acanthocytes, spherocytes, and possibly Howell-Jolly bodies, especially if hemolysis is particularly vigorous. A high (3-7%) reticulocyte count is not unusual during the first three or four days after birth, however, the marrow in this jaundiced infant is proliferating vigorously in response to hemolysis. A call for more red cells is urgent. Immature red cells (in the form of nucleated red cells) and red cells with stippling of RNA (basophilic stippling) are readily identified. Red cell maturation sequence has not been totally processed in the marrow nor is all residual red cell debris removed by the spleen. In the lower photograph are reticulocytes stained by supravital stain (new methylene blue). Basophilic stippling (specks of RNA) stains with both supravital stains and with routine Wright-Giemsa stain.

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Warm antibody hemolytic disease

A 49-year-old male with pneumonia was treated with penicillin. He became jaundiced with yellow sclera. Observe the photograph of his peripheral blood smear. Anisocytosis was observed with pale-centered microcytes and polychromatophilic macrocytes. Since penicillin is a classic offender for autoimmune hemolytic disease, the clinician asked for an antihuman globulin (AHG) test, also known as the Coombs test. A positive AHG reaction occurs when the antibody stimulated by penicillin becomes attached to red blood cells. Hemolysis follows, leaving the patient with jaundice and a peripheral blood smear, as demonstrated in the photograph.

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Sickle cells

This photograph of a peripheral blood smear from an 18-year-old North African woman with anemia reveals sickle cells. Target cells are not conspicuous. This shifts the diagnostic evidence away from HbSC disease. Cells tagged by arrows are variants of sickle cells. These may appear when multiple abnormal hemoglobin combinations are responsible for the clinical problem. The cell marked by the single arrow is an envelope formed not only in HbS disease but in HbC disease as well. Two arrows tag a blister cell, which, when seen in several fields, should prompt a hemoglobin electrophoresis to determine the presence of an undiagnosed hemoglobinopathy. Blister cells with fuzzy edged pseudo-vacuoles (see photo) are to be distinguished from the pseudo-vacuoles (blister)with razor sharp edges suggesting a microangiopathic state.

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Hemoglobin H disease

Hemoblobin H disease follows deletions of 3 of the 4 alpha globulin chains. Beta chains, unable to bind with insufficient numbers of alpha chains, form beta chain tetramers, or HbH.These beta chain tetramers appear as numerous dot size inclusions in erythrocyte cytoplasm, best seen in supravital brilliant cresyl blue stains (lower photograph).The most common molecular defect in alpha thalassemia is DELETION, not MUTATION; whereas, in beta thalassemia, the molecular defect is MUTATION.Leptocytes, as illustrated in the upper photograph,(lepto, derived from a Greek word meaning thin, fine, or slight), are characteristic of HbH disease. They have thinner cell membranes than the cells we recognize as target cells. They stain more lightly than normal erythrocytes and their centers are almost colorless.Subtle changes perhaps, but worth keeping in mind

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A peripheral blood smear was submitted for review. The presence of sickle cells and target cells as shown is diagnostic of hemoglobin SC disease.View Page
Atypical smear: Case follow-up

The patient whose blood smear is shown in the photograph was a 32-year-old female from Virginia who came to the high country of Colorado to ski. The day after arrival, she experienced shortness of breath, fatigue, and upper abdominal pain. She was seen in a medical center in the mountains where a working diagnosis of altitude sickness was made. A CBC revealed RBCs 5.1 x 1012/L, hemoglobin 12.8g/dL, MCV 60fL, hematocrit 40.9%, and normal total WBC, differential, and platelet count. The RDW was normal. Further questioning revealed a previous diagnosis of heterozygous beta-chain thalassemia. No other abnormal hemoglobins were found on hemoglobin electrophoresis, but HbA-2 was elevated to 5%, supporting the diagnosis of beta thalassemia. The patient's poikylocytosis and anisocytosis may be a clue to an underlying erythrocyte abnormality. Persons with iron deficiency anemia may experience various degrees of hypoxia upon arriving at high altitudes. Those with sickle cell disease and thalassemia minor (as in this case) may experience bone pain or other symptoms of "crisis" and/or alteration in the appearance of their erythrocytes upon sudden high altitude exposure. The classic teaching is that in differentiating iron deficiency anemia from thalassemia, increased RDW would favor iron deficiency; normal RDW favors thalassemia.

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A peripheral smear with red blood cells photographed in a typical field was submitted for review. Which of the following conditions might be eliminated because of the cell population found here?View Page
The photograph here is of a peripheral smear sent for hematologic review. No clinical information for the patient was sent with the slide. What is the first course of action that the reviewer should take to assist him/her in interpreting the findings on this blood smear?View Page
The photograph is representative of the peripheral blood smear of a five-month-old immigrant from Asia. Her mother was concerned that the child was not eating well. Her spleen was palpable.The hemogram revealed the following:Hb 9.6g/dL (normal 12.0 - 16.0 g/dL)RBC 5.48 X 1012/L (normal 4.2 - 5.9 X 1012/LHCT 30.4% (normal 37 - 48%)MCV 55.4 fl (normal 86 - 98 fl)MCH 17.5 pg (normal 27 - 32 pg)MCHC 31.6 g/dL (normal 31 - 37 g/dL)RDW 34.9% (normal 11 - 15%)Reticulocyte count 10.9% (normal 0.5 - 1.5%)Select the most likely diagnosis based on the clinical information and peripheral blood findings.View Page
Hb E disease (continued)

The family (cited in the previous case history) was from a region of Thailand where the physician knew HbE carriers are prevalent. Homozygous hemoglobin E is common in Southeast Asia and presents with very mild anemia and seldom requires transfusion. Over 30 million people in the world are HbE carriers, making this abnormal hemoglobin almost as common as HbS. Hemoglobin E is uncommon in North America and in Europe, but with changing immigration patterns, hemoglobinopathy E cannot be ignored. Peripheral blood smear findings of target cells, microspherocytes, red cell hypochromia, a few red blood cell fragments, and nucleated red blood cells require evidence from hemoglobin electrophoresis to establish a diagnosis. Clinically, a very important and severe syndrome is hemoglobin E/beta thalassemia in which there is hemolysis requiring repeated transfusions. The patient has a severe anemia, low MCV (50's), and high RBC. This is characteristic of Hgb E/beta thalassemia.

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The patient, an 8-month-old girl, was anemic, jaundiced, and had splenomegaly. Her family had immigrated from the Middle East. Based on the history and the peripheral blood picture, the most probable diagnosis is thalassemia.View Page
Leptocytes and target cells

The peripheral blood smear of HbH disease presented before is reviewed in the upper photograph.As mentioned, these leptocytes are pale-staining with hemoglobin confined to a thin, flat, cell membrane.Illustrated in the lower photograph are target cells or codocytes (a term derived from a Greek word for hat)Membrane accumulations of phospholipids and cholesterol (particularly in obstructive jaundice) promote target cell formation.When these cells are spread out on a glass slide, a central bump of hemoglobin appears to produce the target, a manifestation of excess cellular membrane compared to the amount of hemoglobin inside.The early descriptions of thalassemias, then called hereditary leptocytosis (Mediterranean anemia, Cooley's anemia), include description of leptocyes, which may have represented HbH disease.

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The blood study from which this smear was obtained revealed an MCV of 115 femtoliters (fl).Normal MCV values in adults= 80 - 90 fl.Normal MCV values in full-term infants= 98 -108 fl.Which of the following conditions may be indicated by the results seen on this peripheral blood smear?View Page
Reporting of laboratory data in regard to blood cell abnormalities

Laboratory data must be presented to clinicians in a user friendly way to promote effective decision making. Databases must be designed to provide clear information that leads quickly to the best patient care outcome. We continue learning how to collect and retrieve laboratory data from our machines, but we are not always in tune to how entry and retrieval of data is geared to and, more directly, influences patient care outcomes. Examples of blood cell abnormalities on a peripheral blood smear that may immediately direct the physician to a specific diagnosis are: (1) presence of target cells as found in thalassemia or hemoglobinopathies and target cells in liver disease, particularly with obstructive jaundice; (2) burr cells as a signal of chronic renal disease and uremia; and (3)atypical neutrophil inclusions relating to genetic disorders. Critical appraisal of such observations could add valuable clues for a diagnosis. Laboratory professionals must establish a set of principles for orderly observation of blood cell morphology, have a clear vision of the applications of their work, and understand the potential clinical implications of their reports and interpretations. Emphasis on values and relevance focuses on patient care outcomes and their dependency on prompt availability of results and contextual interpretations.

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Red Cell Morphology
Examples of Stomatocytes

Examples of stomatocytes can be seen in the center of this slide and to the left of the center. Conditions in which a significant number of in vivo stomatocytes can be seen include hereditary stomatocytosis, neoplastic disorders, liver disease and Rh null disease. The largest numbers of in vivo stomatocytes are seen in hereditary stomatocytosis and their identification is necessary to make the diagnosis.

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Another Target Cell

Another example of a target cell (or codocyte) is seen in the center of this slide. Notice that the hemoglobin in the center of this cell is somewhat lighter in appearance than in the previous slide. A second codocyte can be seen in the upper left portion of the slide. Codocytes appear in conditions which cause the surface of the red cell to increase disproportionately to its volume. This may result from a decrease in hemoglobin, as in iron deficiency anemia, or an increase in cell membrane. Target cells have excess membrane cholesterol and phospholipid and decreased cellular hemoglobin. Examples of other conditions in which target cells may be present include thalassemias, hgb C disease, post splenectomy and obstructive jaundice. Since their presence can be the result of an in vitro artifact, their value in clinical diagnosis is limited.

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The Disappearing Antibody: A Case Study
Risks of transfusing unmatched RBC

We often "get away" with transfusing unmatched RBC because the incidence of unexpected antibodies in patients experiencing medical emergencies is thought to be relatively low ( ~3-5% is sometimes cited, but with little solid evidence).Antibody incidence may vary according to several factors: Genetic disposition Patient's underlying disease Number of prior transfusions Gender (females may get exposed to foreign antigens via fetomaternal bleeds as well as transfusion) Concordance of antigen phenotypes of patients vs blood donors in a given locale.In general, antibody incidence increases with the number of transfusions that are given, although most antibody producers will respond within the first 3 - 4 transfusions. Antibody incidence in transfusion-dependent patients, such as those with sickle cell anemia or thalassemia, is very high. Regardless of likelihood, transfusing uncrossmatched blood to a patient with unexpected antibodies can result in a serious hemolytic transfusion reaction.

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The Urine Microscopic: Microscopic Analysis of Urine Sediment
Match the following:View Page
Formation and Significance of Casts

Casts are cylindrical bodies formed either in the distal convoluted tubules or the collecting ducts of the kidney. Since the walls of the tubule act as a mold for cast formation, the width of the tubule determines the width of the cast. Thus, narrow casts are formed in the distal tubules while broad casts are formed in the collecting ducts. The matrix of all casts is thought to be Tamm-Horsfall protein, a glycoprotein secreted by the distal loop of Henle and the distal tubule. This protein entraps cells and granular material of tubular origin. Very few casts are seen in the urine of a person without renal disease, except for hyaline casts, which may be transiently present after strenuous exercise, and during fever, diuretic therapy, and congestive heart failure. A significant number of urinary casts usually indicates the presence of renal disease.

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Waxy Casts

Waxy casts appear as cylinders of smooth, highly refractive material. They are yellow, homogeneous and their ends may be square or broken off. Cracks may occur within the cast, giving it a segmented appearance. Waxy casts are believed by some to be the final stage of degeneration of the fine granules of granular casts. Since the granules need time to degrade, this finding implies localized nephron obstruction. Waxy casts are seen in chronic renal failure, and acute and chronic renal allograft rejection. Unusually broad waxy casts are known as renal failure casts. These very broad casts are created in the dilated tubules seen in end-stage renal disease.

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Fatty Cast

A fourth type of cast is the fatty cast. Fatty casts are clear cylinders containing droplets of fat which are highly refractile. These casts originate from the breakdown of the tubular epithelium containing oval fat bodies. Fatty casts are characteristic of degenerative tubular disease and are frequently seen with heavy proteinuria.

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Tyrosine Crystals

Tyrosine crystals appear as fine silky needles arranged in sheaves or bundles in acid urine. They are rarely present and may appear together with leucine crystals in liver disease. Do not confuse tyrosine with crystals caused by x-ray dye. X-ray dyes will cause the urine specific gravity to be greatly increased (1.040), Tyrosine crystals are soluble in alkali or dilute mineral acid.

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Which of the following pairs of abnormal crystals may appear together?View Page
Cholesterol Crystals

Cholesterol crystals may be seen in renal tubular disease. These crystals look like plates of glass, sometimes with a notch out of one corner. Under polarized light, they exhibit a stained glass effect. These crystals are rarely seen unless the specimen has been refrigerated, because the lipids remain in droplet form. Large amounts of protein, lipid droplets, fatty casts or oval fat bodies should be found along with cholesterol crystals. Cholesterol crystals are found in acid or neutral urine.

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Tuberculosis Awareness for Healthcare Workers
Trends in Tuberculosis

The tuberculosis (TB) incidence rate in 2007 was the lowest recorded since national reporting began in 1953. However, the average annual percentage decline in the TB rate has slowed. Multi-drug resistant tuberculosis cases have increased. There is persistent disparity in the incidence of tuberculosis between different ethnic groups and also between foreign-born persons and US-born persons. Reference: Pratt R, Robison V, Navin T. Trends in tuberculosis. MMWR/57(11);281 - 285; Centers for Disease Control and Prevention: March 21, 2008. Available at: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5711a2.htm Accessed on May 23, 2008.

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High Risk Progression Groups

The following persons are at high risk for progression from LTBI to TB disease: Persons infected with HIV Persons infected with Mycobacterium tuberculosis within the past two years Persons with untreated or inadequately treated TB disease Infants and children <4 years of age Persons with chronic medical conditions or immunocompromising conditions

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Matching FactsView Page
LTBI Testing Introduction

It is important to identify and treat persons with LTBI to prevent progression to active disease. Currently there are two tests available to identify LTBI.The tuberculin skin test (TST) is performed on the inner arm.The Blood Assay for Mycobacterium tuberculosis (BAMT) is performed on a blood specimen.

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CDC Guidelines

The Centers for Disease Control (CDC) issued Guidelines for Prevention of Tuberculosis in Healthcare Settings in 2005.These guidelines have broader applications than the Guidelines for Prevention of Tuberculosis in Healthcare Facilities issued by CDC in 1994.

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CDC Risk Categories

CDC has identified three risk categories in health-care settings: A low risk healthcare setting is one in which HCWs will most likely not be exposed to persons with TB disease or to clinical specimens that might contain M. tuberculosis. A medium risk healthcare setting is one in which the HCW will or might possibly be exposed to persons with TB disease or to clinical specimens that might contain M. tuberculosis. A potential ongoing transmission healthcare setting is temporarily applied to any setting if there is evidence of person-to-person transmission of M. tuberculosis in the past year.

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Three levels of TB Infection Control

Administrative controls reduce the risk of exposure to persons who might have TB disease.Environmental controls prevent the spread and reduce the concentration of infectious droplet nuclei in ambient air.Respiratory protection controls are for situations that pose a high risk of exposure to further reduce risk of exposure of HCWs to infectious droplet nuclei that have been expelled into the air from a patient with infectious TB disease.

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References

Pratt R, Robison V, Navin T. Trends in tuberculosis. MMWR/57(11);281 - 285; Centers for Disease Control and Prevention: March 21, 2008. Available at: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5711a2.htm Last accessed on May 23, 2008.Respiratory Protection in Health-Care Settings Fact Sheet. Available at http://www.cdc.gov/niosh/99-143.html. Last accessed May 23, 2008. Slide set - Guidelines for preventing the transmission of M. Tuberculosis in Healthcare settings, 2005. Available at http://www.cdc.gov/tb/pubs/slidesets/InfectionGuidelines/program.htm Last accessed on May 23, 2008.Tuberculin Skin Testing Fact Sheet. Available at http://www.cdc.gov/TB/pubs/tbfactsheets/skintesting.htm Last accessed on May 23, 2008.

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Biosafety Levels

Laboratory workers who handle infectious materials in the microbiology laboratory should be aware of the work practices, safety equipment, and barriers that will protect them and others in the area from infectious agents. The Centers for Disease Control and Prevention (CDC) and the National Institutes of Health (NIH) created guidelines to assist laboratories in developing safe practices based on the infectious agents that are handled. These guidelines are referred to as Biosafety Levels 1 through 4. Each increasing number represents increased risk, requiring more stringent work practice and increasingly protective safety equipment and barriers. A copy of the Guidelines can be obtained from the CDC or accessed online at:http://www.cdc.gov/OD/ohs/biosfty/bmbl5/bmbl5toc.htm

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Variations in White Cell Morphology - Granulocytes
Importance of Recognition

It is important to be able to recognize the presence of these changes and then identify them for several reasons:If the changes are pathological, their identification may aid the physician in diagnosing a specific condition.If the changes are not pathological, their identification alerts the physician to the fact that the changes are present, thus avoiding a possible misdiagnosis.If reactive, it indicates that although the cells are functioning normally, they are reacting to a stimulus. Indicating the presence of such cells may aid in determining the diagnosis or monitoring the course of disease once a diagnosis has been made.

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Variations in Morphology

Many variations in morphology may be seen when examining Wright's stained peripheral blood smears. One method of classifying these variations in white cell morphology is based on the way the body responds to a stimulus, deficiency, or the presence of an inherited defect. This classification falls into three groups:Pathological: Cells may show abnormalities in appearance and/or function. The body is responding abnormally to a stimulus or inherited defect, resulting in physiological impairment in the patient. Nonpathological: Cells may show variation in morphology but their function is normal. Their presence does not cause physiological impairment. Reactive: Cells show variation in morphology but are functioning normally in response to a specific stimulus, such as a virus or bacteria. There is a disease process in progress to which the cells are responding. Although the morphology has varied from normal and their presence is significant, the body is responding normally to a stimulus.

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White Cell and Platelet Disorders: Peripheral Blood Clues to Nonneoplastic Conditions
A most useful follow-up test to consider when faced with hypersegmented neutrophils and oval macrocytes (see photograph) in a peripheral blood smear is:View Page
A peripheral smear was submitted for morphology/clinical because of the number of monocytes as captured in the upper and lower photographs. This picture is consistent with each of the following conditions except:View Page


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