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T and B Natural Killer Cells (TBNK) Panel (8000100506)
Test Mnemonic:


Specimen Requirements:

Routine venipuncture.  EDTA (Lavender-top tube); pediatric tube is acceptable.

Specimen that require collection after noon cut-off on Fridays and on weekends may be collected in "Streck BCT" collection tube.


EDTA (Lavender-top tube)

Minimum Volume:

1 ml


Store at room tempreature (18-22C).  DO NOT REFRIGERATE.


48 hours

Causes for Rejection:
  • Clotted sample.
  • QNS sample.
  • Hemolysed sample.
  • Mislabeled sample.
  • Specimen refrigerated.
  • Specimen received in lavender-top tube on weekends or holidays or after noon cut-off on Fridays.
Reference Range:

By report (reports may vary based on patient age and sex)

Turnaround Time:

48 hours


This assay is designed to enumerate percentage and absolute cell counts of lymphocyte subsets in whole blood sample.  Whole blood is added with fluorochrome-labeled antibodies that bind specifically to cell surface antigens on lymphocytes.  After incubation, lysing and fixation, percent and absolute lymphocytes counts are enumerated utilizing an internal quantitation standard. Antiobodies used include CD3, CD4 and CD8 (for T-cells), CD56 (for NK cells), and CD19 (for B-cells).


Samples are accepted in Sample Management Monday-Thursday (8:00 am-5:00 pm), and on Friday by 12:00 pm.

  • CD3, CD4, CD8, CD19 absolute count, NK cells absolute count.
  • Helper T-cell count.
  • Helper T-cells, Cytotoxic T-cells and NK-cells count.
  • Immune Status-Flow Cytometry.
  • Immunosuppressive therapy monitoring for immunocompromised.
Clinical Indication:

Evaluation for acquired immunodeficiencies, primary immunodeficiencies including severe combined immunodeficiency, and for monitoring immune reconstitution following transplantation.

CPT 4 Code:


When ordering tests for which Medicare or Medicaid reimbursement will be sought, physicians should only order tests that are medically necessary for the diagnosis or treatment of the patient. Components of the organ or disease panels may be ordered individually. The diagnostic information must substantiate all tests ordered and must be in the form of an ICD-10 code or its verbal equivalent.
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