Plasma Information and Courses from MediaLab, Inc.

Haptoglobin is the plasma protein responsible for binding free hemoglobin during episodes of hemolysis and would normally demonstrate decreased levels during a hemolytic crisis.The normal level of haptoglobin is 40-330mg/dl. Individuals who are in hemolytic crisis demonstrate greatly reduced levels to an absence of haptoglobin.In alpha thalassemia, however, haptoglobin levels remain normal or only slightly decreased, even during hemolytic events.The reason for this is that haptoglobin functions by binding the alpha chain portion of hemoglobin. With the absence of these chains in alpha thalassemia major and intermedia, haptoglobin cannot bind free hemoglobin. Therefore it is not consumed.

It is important to test for urinary (and plasma or serum) ketones when any patient shows a greater than normal excretion of sugar or reducing substances. Screening for ketonuria is useful in following the effects of treatment for diabetes and in judging the severity of acidosis. Large amounts of ketones will appear in the urine before serum ketone levels are elevated.

The shortest, and least complex of the three pathways, the extrinsic pathway primarily focuses on the interaction of tissue factor with factor VII, leading to the activation of factor VII. Tissue factor, a substance expressed on the surface of cells such as fibroblasts and macrophages found outside the vasculature, initiates coagulation when plasma contained within the vessel walls leaks outside the broken vessel, and comes into contact with these cells. The nomenclature, extrinsic pathway, comes from the fact that tissue factor is external to the vasculature.

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.

The presence of D-dimers in plasma or whole blood indicates that fibrin has been formed and degraded (fibrinolysis). Plasmin can also degrade intact fibrinogen, generating fibrinogen degradation products that are detected in fibrin/fibrinogen degradation products (FDP) assays. D-dimers and FDP can become elevated whenever the coagulation and fibrinolytic systems are activated. The presence of D-dimer confirms that both thrombin and plasmin have been generated since it can only be produced as the result of the plasmin degradation of fibrin. This makes the test for D-dimers more specific for fibrinolysis than the FDP test that also detects the products of the direct proteolysis of fibrinogen (fibrinogenolysis).The D-dimer test can be useful in the diagnosis of deep venous thrombosis (DVT) or pulmonary embolism (PE), two forms of venous thromboembolism (VTE). When the test is being used for this purpose, it is important that D-dimer levels are accurately measured and accurately reported because of the serious nature of this clinical decision. If the test is positive in a patient suspected to have DVT or PE, clinicians proceed with further diagnostic tests. If the test is negative, depending on the clinical situation and the sensitivity of the D-dimer assay, DVT or PE is considered unlikely and further diagnostic tests for DVT or PE might not be pursued. D-dimer is a sensitive, but not specific, diagnostic test for disseminated intravascular coagulation, and an indicator of increased risk of future myocardial infarction in patients evaluated for chest pain.

Used to determine the cause of an unexpected, prolonged PT or APTT. This test is performed after mixing studies have been run, because factor assays are able to identify specific factor deficiencies or inhibitors. Think of mixing studies as being the screening test, while factor assays are confirmatory tests for specific factor deficiencies. The test itself is involves performing a PT and APTT, except that plasma known to be deficient in a specific factor type is combined with the patients plasma, comparing the resultant time to a standard curve. The percent of activity, and amount of correction with normal plasma determines the specific factor deficiencies.

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.

Some global specimen collection and handling issues to consider include: Specimens that contain nucleated cells will be of interest in DNA methodologies while specimens lacking nucleated cells are more useful in RNA methodologies. rRNA is more stable than mRNA, which is labile and sensitive to contamination. DNA is relatively stable and can be obtained from nonviable sources. Serum or plasma obtained by standard routine venipuncture procedures can be used as long as proper site selection and decontamination occur. Standard anticoagulants such as Ethylenediaminetetraacetic Acid (EDTA) and Acid Citrate Dextrose (ACD) can be used; however avoid the use of heparin as an anticoagulant as it interferes with some polymerase chain reaction (PCR) methodologies. When using fluorescence, fasting serum or whole blood specimens should be used to decrease the interference by lipids.

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.

Consists of an electrolyte panel, plus: Blood urea nitrogen (BUN), which a measure of renal function. Creatinine (Creat), which also measures renal function Glucose, the most important blood sugar, and Calcium. Run on serum or plasma

Blood is tested for the most important electrolytes (salts): Sodium (Na) Potassium (K) Chloride (Cl) Carbon dioxide (CO2)Can be run on serum or plasma.

Hemolysis means the breakup of fragile red blood cells within the specimen, and the release of their hemoglobin (the red oxygen carrying substance present within the red cells), and other substances, into the plasma.A hemolyzed specimen is one which has undergone hemolysis. A hemolyzed specimen can be recognized after it is centrifuged by the red color of the plasma.

Drugs and toxins including therapeutic drugs and drugs of abuse may be present in the plasma. Other substances too numerous to mention are also present in plasma.

Plasma is the liquid portion of the blood. It contains many substances including:Water Electrolytes Sugars Proteins Lipids Drugs & Toxins

Water is the largest component of plasma, and makes up about 53% of whole blood.

Sugars are also dissolved in the plasma. By far the most important is glucose. Blood glucose is increased in diabetes mellitus, and decreased in hypoglycemia.

Circulating whole blood is a mixture of: Plasma (which contains fluid, proteins, and lipids), and Formed elements, consisting of red cells, white cells, and platelets.

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.

Autoagglutination is seen in this slide, as evidenced by cells clumping together rather than stacked like coins. Autoagglutination is caused by the presence of antibody in the plasma. High titers of antibody are needed for the demonstration of autoagglutination on a Wright’s stained smear.

The following factors promote the formation of casts in the kidney:Larger than normal amounts of plasma proteins entering the tubules,Decreased pH.Decreased urinary flow rate.Increased urine concentrationAfter formation, casts are washed loose from the tubules and discharged into the urine, where they can be found its sediment.

Plasma cells are uncommonly observed in the peripheral blood smear.They are normal constituents of lymph nodes, spleen, connective tissue and bone marrow. The presence of plasma cells in the peripheral blood is indicative of a large number of conditions mostly related to infections , immune disorders, malignancies, toxic exposures, hypersensitivity reactions and their responses.Although mature plasma cells have a distinct appearance, they still may be confused morphologically with immature plasma cells and other cells with inclusions, reactive changes or nucleated red bloods cell with altered identities.In the upper and lower photographs are plasma cells with features mindful of myeloma cellsThe large myeloma cell in the upper photograph has an eccentric immature nucleus with a muddy chromatin pattern.Note also clumping and stacking of the erythrocytes, bordering on rouleaux formation ,implicating an increase in plasma gamma globulin.The plasma cell with the double nucleus in the lower photograph is particularly suggestive of myeloma.Further studies are in order including a bone marrow examination where at least 30% of bone marrow cells should be variations of mature and immature plasma cells.Serum electrophoresis will reveal a monoclonal globulin spike, and light chains in excess of 1.0 gm/24 hours may be seen in the urine.The presence of lytic bone lesions is a convincing clinical clue.With these findings in combination, a diagnosis of myeloma can be made with assurance.