Lymphocyte Subsets
Lymphocytes are a type of white blood cell with specialized roles in immune function. T-lymphocytes are the most common lymphocyte. The two major classes of T-cells are T-helper cells, which help other immune cells, and T-cytotoxic cells, which kill cancer cells as well as virus-infected cells and foreign cells directly. B-lymphocytes recognize pathogens and other foreign proteins, they also evolve cells that can make antibodies to the pathogen or the foreign antigen. Antibodies are highly specific to their target antigen. By attaching to their specific targets, antibodies mark these antigens for destruction by other cells. T- and B-lymphocytes are components of the adaptive immune system, which is able to learn and retain the memory of pathogens and foreign antigens. The natural killer lymphocyte is part of the innate immune system which kills virus-infected and cancer cells directly.
To assess whether counts and relative frequencies of common lymphocyte subsets are within normal limits for age, and thus indicative of general health of the cellular immune system.
Lymphocyte subsets include cells that are labeled by specific markers: CD3 for T-cells, CD4 for T-helper cells, CD8 for T-cytotoxic cells, CD19 for B-cells, and CD16/CD56 for NK cells. These cells are characterized by counts and relative frequencies.
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CATEGORY
DETAILS
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Assay Category
Lab-developed test, lymphocyte phenotyping.
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Intended Use
To measure counts and relative frequencies of lymphocytes in peripheral blood.
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Methodology
Labeling of peripheral blood lymphocytes with dye-labeled antibodies to cell-specific markers, flow cytometry.
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Test Report
Available within 6 hours of receiving a blood sample.
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Test Readout
Counts and relative frequencies of CD3, CD4, CD8, CD19, and CD16/56 lymphocytes.
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Reference Range
Please see the test report for the reference range.
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Test Interpretation
Results within the reference range are seen in healthy individuals.
Purpose
Knowledge about counts and relative frequencies of lymphocyte subsets can be used to assess the general health of the cellular immune system.
Rationale
The adaptive immune system protects individuals. The health of the cellular immune system can be assessed in its simplest form by circulating white blood cells called lymphocytes. Lymphocytes are comprised of T-lymphocytes which mediate direct killing of offending cells (T-cytotoxic cells) and provide help to other types of lymphocytes (T-helper cells). B-lymphocytes recognize foreign antigens and also make antibodies, and serve as precursors to plasma cells, which are long-lived antibody-producing cells. Natural killer (NK) lymphocytes also mediate the direct cytotoxic effect. Adequate numbers and relative frequencies of these lymphocyte subsets provide a first level assessment of the integrity of the cellular immune system. These numbers and frequencies differ by age.
Intended Use
To assess whether counts and relative frequencies of common lymphocyte subsets are within normal limits for age, and thus indicative of general health of the cellular immune system.
Procedure
PlexEBV™ measures functional cell-mediated immunity to EBV.
Performance
Benefits
Insurance coverage
Plexision will bill the patient's insurance plan and work directly with the insurer for payment. Plexision will assist with the cost of Pleximark™ if there is no insurance coverage. For additional information, call 1.855.753.9474 or email info@plexision.com
Sample & Handling
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Sample Type
Whole blood is collected in a sodium heparin (green-top) tube.
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Volume
3 mL in children and 5 mL in adults.
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Transport Conditions
Ship priority overnight, at room temperature. The sample must get to Plexision within 30 hours of the phlebotomy.
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Specimen Stability
30 hours at room temperature from the time of phlebotomy.
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Sample Discard Criteria
How To Order
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CATEGORY
DETAILS
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Test Brochure
View and download the product brochure here.
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Ordering Tests
Please complete this form, print, and fax to 412-224-2776.
What are lymphocyte subsets?
Lymphocytes are a type of white blood cell. The different types of lymphocyte include a) T-cells that kill foreign cells such as viruses, bacteria, or transplanted cells directly. T-cells also help other lymphocytes mount defensive responses. Another lymphocyte, b) B-cells, recognize foreign antigens, make antibodies, or transition to long-lived antibody-producing cells, and c) NK cells which also kill foreign cells directly, and help with antibody-mediated immune defense.
Who can benefit?
Individuals who show evidence of impaired immune function such as frequent infections, cancers, and those who are receiving immune suppressive medications can benefit from measurement of lymphocyte subsets.
What is involved in measuring lymphocyte subsets?
Half to one teaspoon of blood is drawn for a sample. White blood cells are then purified and lymphocyte subsets are counted using a flow cytometer. Results are reported on the same day that the sample is received at the laboratory.
How long does it take to get results?
Results are reported on the same day that the sample is received at the laboratory.
How does the test work?
The test determines whether counts and percentages of one or all lymphocyte subsets are normal, increased, or decreased compared with corresponding values in healthy people.
How do I interpret the test results?
The results are reported as an Index of Rejection (IR). An index less than 1.15 implies a decreased likelihood of rejection. An index of 1.15 or greater implies an increased likelihood of rejection.
What are the benefits of measuring lymphocyte subsets?
Abnormal counts and frequencies of one or all lymphocyte subsets can guide the selection of subsequent diagnostic tests to confirm whether a specific immune deficiency is present or not.
How do I order lymphocyte subsets?
Lymphocyte subset testing must be ordered by your healthcare provider. The test requisition form is provided on http://plexision.com/PlexEBV/ordering-information. The completed form can be faxed to 412-224-2776. If there are any questions, please contact (855) PLE.XISION (753.9474) or 412-224-2504.
Is lymphocyte subset testing covered by insurance?
Plexision will bill your healthcare facility or your insurance plan as indicated on the requisition form. Plexision’s patient assistance plans will assist you with the cost of the lymphocyte subset if there is no insurance coverage.
Lymphocyte subsets are a lab-developed blood test.