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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.

Knowledge about counts and relative frequencies of the abovementioned lymphocyte subsets can be used to assess the general health of the cellular immune system:

 

# CATEGORY DETAILS

1

Assay Category

Lab-developed test, lymphocyte phenotyping.

2

Intended Use

To measure counts and relative frequencies of lymphocytes in peripheral blood.

3

Methodology

Labeling of peripheral blood lymphocytes with dye-labeled antibodies to cell-specific markers, Flow Cytometry.

4

Test Report

Available within 6 hours of receiving a blood sample.

5

Test Readout

Counts and relative frequencies of CD3, CD4, CD8, CD19, and CD16/56 lymphocytes.

6

Reference Range

Please see the test report for the reference range.

7

Test Interpretation

Results within 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

PlexEBVTM measures functional cell-mediated immunity to EBV.

  • A whole blood sample of 3 mL in children and 5 mL in adults is collected in sodium heparin tubes.
  • Peripheral blood leukocytes are purified.
  • Cells are stained with dye-labeled antibodies to CD3 (T-cell), CD8 (T-cytotoxic), CD4 (T-helper), CD19 (B-cell), and NK (CD16/56) cells.
  • Cells are counted by flow cytometry.
  • Results are reported on the day that the blood sample is received at the laboratory.

Performance

  • Counts and frequencies are provided for each of the abovementioned cell types.
  • Reference ranges for each cell type are provided by age.

Benefits

  • Normal counts and frequencies of lymphocyte subsets occur in healthy individuals with a healthy immune system.
  • Abnormal counts and frequencies of common lymphocyte subsets are often the first anomalies in cellular immune deficiencies.
  • Abnormal counts and frequencies of a specific lymphocyte subset can guide the selection of subsequent diagnostic tests to diagnose a specific immune deficiency.

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 & Shipping

# CATEGORY DETAILS

1

Sample Type

Whole blood collected in a sodium heparin (green-top) tube.

2

Volume

3 mL in children and 5 mL in adults.

3

Transport Conditions

Ship priority overnight, at room temperature. Sample must get to Plexision within 30 hours of the phlebotomy.

4

Specimen Stability

30 hours at room temperature from the time of the phlebotomy.

5

Sample Discard Criteria

  • Transport time more than 30 hours from the phlebotomy.
  • Lithium heparin (green-top) tube or ACD (yellow-top) tube.
  • Clotted, hemolyzed, frozen, refrigerated, or broken vacutainer seal.

How to order

# CATEGORY DETAILS

1

Test Brochure View and download the product brochure here

2

Ordering Tests

To order tests or clarify questions, please reach us via email info@plexision.com or call us at +1 (855) 753-9474

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.

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.

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.

Results are reported on the same day that the sample is received at the laboratory.

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.

The test provides counts and percentages of the different lymphocyte subsets seen in healthy individuals. These results should be discussed with your physician who can further explain what they mean.

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.

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.

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.

About

Plexision develops cellular biomarkers for personalized diagnosis and drug development in solid organ transplantation and immunological disorders. We also pioneer in R&D projects centered on integrating biomarker targets in all phases of drug development, from preclinical to post-marketing. Plexision’s technology can be adapted to

  • - Assess disease risk for several immunological disorders.
  • - Predict the success of a drug for a specific patient.
  • - Develop dosing recommendations for new immunological drugs.

Our state-of-the-art laboratory is CLIA-certified and located in Pittsburgh, PA.

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