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The silent carrier state of beta thalassemia, B++s/B, involves one minor beta chain deletion or mutation. This state produces such a small drop in the level of beta chain synthesis that the alpha to beta chain ratio remains at a near normal state.Hemoglobin A levels remain normal (98% or higher).(drawing modified from Harmening, 1999)

CK-isoforms are also markers of myocardial necrosis. Using high voltage electrophoresis, subtypes of CK-MM and CK-MB, CK isoforms, can be isolated. They are released in myocyte necrosis and are not ordinarily in peripheral circulation. CK-MB has 4 isoforms; CK-MB1 and CK-MB2 are released 2-4 hours after chest pain, peak in 6-9 hours and like myoglobin, are early markers of an AMI.CK-isoforms are not widely measured in evaluating chest pain and ACS due to the labor intensive procedure that is required (high voltage electrophoresis). When CK-isoforms are used, most often a ratio of CK-MB2/CK-MB1is reported. A ratio of <1 is negative for myocardial necrosis; a ratio >1.7 is positive for myocardial necrosis.

A calculation is used to correct CSF WBC counts which are falsely increased due to a traumatic tap: WBCs added = WBC(blood) x RBC(CSF) / RBC(blood)The blood WBC count is multiplied by the ratio of the cerebrospinal fluid RBC count to blood RBC count.The result is the number of artificially introduced WBCs. The true CSF white cell count is then calculated by subtracting the artificially introduced WBCs from the actual CSF WBC count. If the patient's peripheral WBC and RBC counts are within normal limits, some laboratories use the following formula: Subtract one white cell from the CSF WBC count for each 750 RBC counted in the spinal fluid.

Another example of a malignant cell. This cell has a smooth chromatin pattern similar to the chromatin pattern commonly seen in blast cells. This cell has a high nuclear to cytoplasm (NC) ratio which is typical for malignant cells. No nucleoli are visible in this cell although malignant cells often have large nucleoli.

Improper collection of the blood specimen that is used for testing can cause false prolongation of PT or aPTT results. The following table covers several preanalytical variables that may affect PT or aPTT test results Preanalytical Variable Cause of False Elevation of PT and or aPTT Test Result Corrective Action Blood collection tube is inadequately filled. Improper ratio of blood to anticoagulant. Excess anticoagulant causes prolonged PT or aPTT result. Recollect specimen ensuring proper fill to achieve a blood to anticoagulant ratio of 9:1. Patient has a hematocrit level above 55% Improper ratio of blood to anticoagulant. Excess anticoagulant causes prolonged PT or aPTT result. Prepare a specimen collection tube that contains less anticoagulant. Refer to your laboratory's procedure for the proper amount of anticoagulant. Specimen is clotted. Coagulation factors have been activated; insufficient levels left in the plasma. PT and aPTT results will be affected. Recollect the specimen. Specimen collected from an arm with a heparin lock or from a heparinized vascular access device (VAD). Heparin contamination will prolong the aPTT. Collect the blood from a vein rather than a VAD. If blood must be drawn from the VAD, flush it first with 5 mL of saline, and discard the first 5 mL of blood before collecting the specimen. Patient is receiving heparin therapy. Heparin will prolong the aPTT If the patient is being evaluated for possible factor deficiencies or coagulation inhibitors, use a heparin digesting enzyme as a pretreatment before testing the PT or aPTT. .

A mixing study should be considered when a patient has a prolonged PT and/or aPTT along with: no history of heparin or warfarin therapy no history of liver disease It is also essential to first verify that a correctly collected sample (free from clots) with a proper blood to anticoagulant ratio has been obtained.

Recall that the inflammatory events leading to atherosclerosis are due to the presence of LDL particles which diffuse through the endothelium and into the vessel wall. It makes sense that the more LDL particles there are, the more risk there would be for LDL depositing in the vessel wall. It would seem therefore that measuring the number of LDL particles could be more useful than measuring the cholesterol content of the particles. Traditional measurements of LDL-C quantify the amount of cholesterol associated with all the LDL in a patient sample; they don't tell us how many LDL particles there are. An analogy can be made with battleships. If you wanted to measure the size of a navy that was sailing for your shores, it makes more sense to count the number of ships than to count the amount of cargo the ships carry in order to estimate the number of ships. Of course, it is intuitive that the more LDL-C there is, the greater the number of LDL particles. In that sense, LDL particle number should correlate to LDL cholesterol, and this is indeed true. However, studies now show that measurement of the number of LDL particles is a more powerful predictor of cardiovascular risk. The exact relationship between LDL particle number and cholesterol content actually varies due to the fact that the lipoproteins vary in size and in the ratio of triglycerides to cholesterol. So, although cholesterol is related to LDL particle number, it is not in perfect proportion.How can we then measure LDL particle number? The most obvious way would be to measure apolipoprotein B100 (often abbreviated ApoB). Each LDL particle has one molecule of ApoB attached to it. Therefore, if we measured ApoB, we would be measuring the number of LDL particles, not the contents of those particles, and number appears to be more important with regard to adverse outcomes.

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.

The specimen of choice for coagulation testing is plasma. Venous blood is drawn into a 3.2% buffered sodium citrate tube (blue top tube), yielding a whole blood sample with a 9:1 blood to anticoagulant ratio. Inadequate filling of the collection tube will decrease this ratio, and may affect test results. A blue top tube used for coagulation testing should be drawn before any other tubes containing additives. This includes tubes containing other anticoagulants and/or plastic serum tubes containing clot activators. A serum tube that does not contain an additive can be collected before the blue top tube. If a winged blood collection set is used in drawing a specimen for coagulation testing, a discard tube should be drawn first. The discard tube must be used to fill the blood collection tubing dead space to assure that the proper anticoagulant/blood ratio is maintained, but the discard tube does not need to be completely filled. The discard tube should be a nonadditive or a coagulation tube. If a blood specimen used for coagulation testing must be collected from an indwelling line that may contain heparin, the line should be flushed with 5 mL of saline, and the first 5 mL of blood or 6-times the line volume (dead space volume of the catheter) be drawn off and discarded before the coagulation tube is filled.

Because hybridization involves nucleotide bases and the separation and joining or reannealing of strands, several environmental factors can influence this process: Temperature: If the temperature is too high, the strands melt. If it is too low, they might be forced together. The pH: A pH that is too alkaline will cause the strands to separate; too acidic and they are forced together. The guanine to cytosine ratio (G:C ratio): Since this bond is stronger than the other nucleotide bonds, if the G:C ratio in the desired target strand is high, the separation process may take longer.

The sample in the first syringe is quickly delivered into a watchglass or onto a slide. After the technologist verifies the presence of white-gray marrow particles in the sample, push smears and/or coverslip smears from this unanticoagulated sample are made immediately. All films should be rapidly air dried. The appearance of fat as irregular holes in the films also give the assurance that marrow and not just blood has been obtained. This type of smear is referred to as a direct smear and is usually used to evaluate morphology. Although some evaluation of cellularity and M:E ratio is possible, particle smears or biopsy sections provide a more accurate representation of these factors.

Examination of Wright-Giemsa stained bone marrow preparation involves examination under low power (10X objective) high power (40-50X objective )and oil immersion (100X objective). Low power examination: Assess quality of smear, assess number of megakaryocytes.Assess myeloid to erythroid ratio.Evaluate morphology and do differential count.

A normal M:E ratio is depicted in this slide. Notice that the area shown is a portion of the slide near a particle or spicule of marrow where the cells are numerous. The morphology can still be clearly differentiated. The small dark cells scattered throughout the slide are erythroid cells, while the larger, lighter staining cells are myeloid cells. The normal M:E ratio varies from 1.2 to 5 myeloid cells for each erythroid cell.

Another example of a normal M:E ratio in a thicker, more representative area of the smear. The cells shown by the arrows are erythroid precursors.

An example of a decreased M:E ratio in a thin area of the smear. A decreased M:E ratio means that the myeloid cells are decreased in number when compared to the erythroid cells. Approximate ratio is 1:2.

High power (40x objective) examination can be used to estimate the myeloid-to-erythroid ratio. The erythrocytes are nucleated, immature erythrocytes. Under high power, nucleated red cells appear to have a dark purple nucleus as opposed to the lighter staining nucleus of the myeloid or granulocyte series. Lymphocytes also have a dark staining nucleus and some may be erroneously included in the erythroid estimate. In the normal marrow these numbers are insignificant.

A thin area of a slide taken from a patient who has chronic lymphocytic leukemia, which is characterized by an increased number of small lymphocytes in the bone marrow. At this power, numerous small dark cells similar in appearance to immature red cells are seen, but can be quickly confirmed as lymphocytes when viewed under oil. The actual M:E ratio is normal, since lymphocytes are not included in the final ratio. The arrows show several cell most likely representing small lymphocytes. Some small lymphocytes are normal in the bone marrow.

There is little doubt that antimicrobial use increases the risks for CDAD and certain compounds or classes of compounds are associated with increased risk, however the exact role (risk) of each compound is still to be elucidated. With all pharmaceutical products, use is based on a risk-benefit ratio; that is, if the patient will benefit to the extent that using the particular antimicrobial is warranted, risks associated with its use are accepted as a part of patient management. There are a number of new antibiotics in various stages of development eg nitazoxanide, ramoplanin, though none to date have FDA approval for treatment of CDI.Little is currently known about the relationship between strain virulence, disease severity, and transmission. Also while the role(s) of Toxins A and B in CDI are well established, the role of the Binary Toxin is not well understood and research is necessary to assess its role in C. difficile disease.Monoclonal antibodies against C. difficile toxins are under development as a form of treatment to induce passive immunity in patients.Anti-Clostridium difficile vaccines are also being researched.

N:C Ratio - Nuclear: cytoplasmic Ratio - The ratio of nuclear volume to cytoplasmic volume within any one cell.Neoplasm - Any new and abnormal growth, such as a tumor.Neutrophilic Granules - Specific granules present in the cytoplasm of neutrophils. These granules resemble pencil stippling and stain a lilac color due to their affinity for both basic and acid dyes.Phagocyte - Any cell that ingests microorganisms or other cells and foreign particles.Phagocytosis - The ingestion and destruction of microorganisms or other foreign particles.Plasma - The fluid portion of blood in which the various blood cells are suspended.PF3 (platelet Factor 3) - A lipoprotein component of the platelet membrane; functions as a surface catalyst during blood coagulation.Pseudopod - A temporary protrusion of the cytoplasm of a cell.Refractile - Capable of refracting or changing the direction of light.Senescence - The process or condition of growing old.Serotonin - A constituent of blood platelets and other cells and organs; induces constriction of the blood vessels.Specific Granules - Granules found in cells of the more mature stages of the granulocytic series. They have distinct staining reactions which differ with each type of granulocyte.T-cell - Thymus derived lymphocyte which mediates cellular immunity.Thrombocyte (Platelet) - A circular or oval disk found in the blood; concerned with hemostasis.Thymus - A ductless gland-like body situated in the anterior mediastinal cavity; reaches its maximum development during the early years of childhood.Vacuole - Any small space or cavity formed in the cytotoplasm of a cell.

Band neutrophils are also referred to as stabs or simply as bands. The diameter of a band is approximately 9-16 microns, and its nuclear to cytoplasmic (N:C) ratio is 1:2.

Basophil is also known as basophilic granulocyte and baso. Basophils are easily recognized because of their large, dark granules. The basophil's diameter is 9-15 microns, and its N:C ratio is approximately 1:3.

Lymphocytes are a heterogeneous group of cells that have different origins, lifespans and functions, and vary markedly in size. Some have a diameter of approximately 7ì, while others are as large as 18ì. The variations in size are mainly due to different amounts of cytoplasm. Therefore, the N:C ratio may range from 5:1 in some lymphocytes to 1:2 in others.

Some drugs are more efficiently monitored by determining their effects rather than by measuring the serum drug level. Warfarin dosing, for example, is better monitored by measuring the Prothrombin time (PT) and International Normalized Ratio (INR).

Contain anticoagulant Ethylendiaminetetraactic acid (EDTA) to prevent clotting. Are used mostly for hematology studies. Must be completely filled to assure a correct anticoagulant to blood ratio. Must be inverted after filling to assure proper mixture of anticoagulant with blood.

Insufficient blood volume (short draws) within a collection tube containing anticoagulant will result in an incorrect ratio of blood to anticoagulant, and yield incorrect test results.Short draws can be caused by: A vein collapsing during phlebotomy.The needle coming out of the vein before the collection tube is full.Loss of collection tube vacuum before the tube is full. (Always keep extra tubes on hand.) 

Examples of conditions in which spherocytes can be seen include hereditary spherocytosis and immune hemolytic anemias (i.e., ABO incompatibility). Spherocytes can also form in conditions where there has been a direct physical or chemical injury to the cells. An example would be a smear from an individual who has suffered severe burns. In hereditary spherocytosis, a condition where spherocytes are numerous, the MCHC value will be at the upper limits of normal, or about 36. The identification of spherocytes on the smear of a patient with hereditary spherocytosis can aid significantly in the diagnosis of the disorder. In Artifactual spherocytes can appear when blood is stored for a prolonged period of time.

Fill blood collection tubes completely (until vacuum is exhausted) to ensure the correct blood to anticoagulant ratio necessary for accurate patient results. Specimens may be rejected by the laboratory if the tube is short-filled or over-filled. To avoid short-filling of tubes, the phlebotomist must ensure that the blood flow stops completely before removing the tube from the needle. When using a winged device (butterfly) to collect blood for coagulation studies (e.g., protime, aPTT), the phlebotomist must draw a light blue top "waste" tube before attaching another light blue top tube for testing. If the air in the tubing of the winged device is not displaced into a waste tube and is drawn into the tube used for testing, the tube used for testing will short-fill. The laboratory may reject the specimen because of invalid blood to anticoagulant ratio.

Each tube used for blood collection is labeled by the manufacturer with important information. This information includes: tube volume in milliliters (mL), expiration date, lot number and, if applicable, the type of additive that is in the tube. Tube volume: Each tube contains a vacuum that allows a specific amount of blood to enter the tube. In a tube that contains an anticoagulant, the amount of blood that is drawn into the tube will establish the correct blood to anticoagulant ratio. Tubes not filled to the correct volume (over-filled or under-filled) may cause inaccurate test results. Expiration Date: An expiration date is stamped on all blood collection tubes. The tube manufacturer determines this date based on its studies of vacuum maintenance and anticoagulant effectiveness. The expiration date should be checked routinely; tubes that are past the expiration date should be discarded.If a blood collection tube is used past its expiration date, the vacuum may not draw the amount of blood needed to fill the tube completely. Short-filled tubes may not be acceptable for testing and the specimen would have to be recollected. If the tube contains an anticoagulant, it may not work effectively (may not prevent the blood from clotting). Lot Number: A lot number listed on the tube identifies a specific group of tubes that were manufactured at the same time. This information is important to know if a problem is identified with several collection tubes. If the defective tubes are all part of the same lot number, the manufacturer should be notified for replacement of the tubes. Additive: Most blood collection tubes contain a type of additive or chemical that, when mixed with the blood, will yield a specimen acceptable for testing. The various types of additives that are contained in blood collection tubes are discussed on the following page.

In this case the patient's antibody has disappeared from the plasma by adsorbing to transfused donor red cells. It is detectable but unidentifiable in the post-transfusion red cell eluate. Several trial and error procedures exist to enhance weak antibodies. Which methods will enhance the reactivity of a given antibody depend on its characteristics. Methods to investigate weak antibodies include: Use a higher plasma to red cell ratio (add more antibody-containing plasma or eluate) Increase incubation time (if consistent with manufacturer instructions, if applicable) Use enzyme-treated panel red cells (enzymes enhance IgG antibodies in Rh and Kidd blood systems but denature some antigens, e.g., Fya, Fyb, S) Try alternative antibody detection methods, e.g., if using LISS routinely, try polyethylene glycol (PEG) or column agglutination methods such as gel, providing they have been validated for use in the TS laboratory.

A normal bone marrow smear stained with Wright/Giemsa stain is captured in this photograph.Note the normal maturation sequence beginning with myelocytes (the two large cells in the left upper corner)through metamyelocytes, band neutrophils,and multi-lobed segmented neutrophils.The small cells with darkly staining, centrally placed nuclei are normoblasts (three are clustered in the left lower field).Absent in this field are eosinophils, basophils and megakaryocytes.A normal M:E ratio of 2.4:1 is calculated from the twelve myeloid cells and five normoblasts. Two lymphocytes are identified, one left center, the other left upper.

In this photograph of blood cells from yet another submitted slide, we find cells resembling lymphoblasts with increased nuclear/cytoplasmic ratios and dense, finely meshed nuclear chromatin. In addition, note the extrusion of delicate strands of cytoplasm from the outer cell membranes (blue arrow). These are cells connoting hairy cell leukemia (HCL). Under scanning electron microscopy, the cytoplasmic extensions appear to be either slender microvilli or delicate pseudopods. The most helpful confirmatory finding is the detection of acid phosphatase isoenzymne 5 in the cytoplasm of suspected hairy cells by staining. The enzyme concentrates primarily in golgi bodies and in the nuclear membrane and its staining is not inhibited by the addition of tartrate. Stated in another way, hairy cells on the peripheral smears are detected by their staining positively for tartrate-resistant acid phosphatase. Be suspicious of HCL if marrow resists aspiration-a consequence of reticulin fibrosis of the marrow in HCL.