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Test Code TBNK TBNK Panel

Additional Information

Determining percentages or counts of CD3+CD4+ lymphocytes can be useful in monitoring human immunodeficiency virus (HIV).  Individual with HIV typically exhibit a steady decrease of CD3+CD4+ lymphocyte counts as the infection progresses.  CD3+CD4+ percentages or counts and total T and B lymphocytes are used to characterize and monitor some forms of immunodeficiency and autoimmune diseases.  NK lymphocytes identified as CD3- and CD16+ and/or CD56+ have been shown to mediate cytotoxicity against certain tumors and virus-infected cells.  NK-mediated cytotoxicity does not require class I or class II major histocompatibility complex (MHC) molecules to be present on the target cell.

Collection Container

Lavender EDTA

Specimen Volume

4mL Lavender (EDTA) tube

Minimum Specimen Volume

1 full lavender EDTA tube or Microtainer

Transport Temperature

Room temperature

Specimen Stability

Transport specimen to the Flow Cytometry laboratory as soon as possible.

Reasons for Rejection

Specimen refrigerated or exposed to extreme heat; specimen clotted or hemolyzed; specimen more than 72 hours old when received in the laboratory.


Numeration of specific subpopulations and monoclonal antibodies to lymphocyte antigens by flow cytometry.

Days and Times Performed

Draw anytime, test performed day shift Monday-Saturday,  not on Sunday, or holiday (holidays include the weekdays celebrated by Baystate Medical Center when an actual holiday falls on a weekend).  The specimen is acceptable as long as it is received by the Flow Cytometry Laboratory within 72 hours of collection.

Reference Ranges


CD3+/CD4+ (T-helper cells):  39-64%, 524-1556 cells/mm3

CD3+/CD8+ (T-suppressor cells):  9-31%, 116-762 cells/mm3

CD3+ (total T-cells):  60-68%, 679-2382 cells/mm3

CD19+ (B-cells):  6-26%, 83-616 cells/mm3

CD3-(CD16+CD56)+ (Natural Killer cells):  3-20%, 41-411 cells/mm3

CD4/CD8 ratio:  1.345-6.400

CPT Code

86355; 86357; 86359; 86360



EMR Interface Order Code