ARUP's Laboratory Test Directory

Lymphocyte Subset Panel 5 - Total Lymphocyte Enumeration : 0095892
[ image for: Time Sensitive]
Time Sensitive
  


Mnemonic: TIMMUNPAN

Methodology: Quantitative Flow Cytometry
Performed: Sun-Sat
Reported: 1-3 days
Specimen Required: Collect: Lavender Hemogard (EDTA), pink Hemogard (K2EDTA), or green Hemogard (sodium or lithium heparin). Hemogard tubes are preferred for laboratory safety.

Specimen Preparation: Transport 4 mL whole blood. (Min: 0.5 mL)

Storage/Transport Temperature: CRITICAL ROOM TEMPERATURE.

Remarks: Specimens must be analyzed within 72 hours of collection in EDTA or 48 hours in heparin. Some medications may affect immunophenotyping results and should be listed on the test request form.
New York State Clients:
Only EDTA specimens may be submitted and must be analyzed within 30 hours of collection.


Unacceptable Conditions: Frozen or refrigerated specimens. Specimens older than 72 hours in EDTA or 48 hours in heparin. Clotted or hemolyzed specimens.
New York State Clients:
Specimens collected in heparin. Frozen or refrigerated specimens. EDTA specimens older than 30 hours. Clotted or hemolyzed specimens.


Stability (collection to initiation of testing): Ambient: 72 hours in EDTA, 48 hours in heparin; Refrigerated: Unacceptable; Frozen: Unacceptable
New York State Clients:
EDTA: Ambient: 30 hours; Refrigerated: Unacceptable; Frozen: Unacceptable


Reference Interval:
Reports include age appropriate reference intervals and interpretation.
 
Components Reference Interval
% CD4 (Helper T-cells)
Absolute CD4
By report
% CD8 (Suppressor T-cells)
Absolute CD8
By report
% CD3 (Total T-cells)
Absolute CD3
By report
% CD19 (B-cells)
Absolute CD19
By report
% NK-cells
Absolute NK-cells
By report
CD4: CD8 ratio By report

Interpretive Data: In this test, the CD4 cells are Helper T-cells because they express both CD3 and CD4. The CD8 cells are Suppressor T-cells because they express both CD3 and CD8. The B-cells express CD19, but not CD3. The NK-cells express either CD16 or CD56 (or both) but not CD3. Helper T-cell levels are a criterion for categorizing HIV-related clinical conditions by the CDC's classification system for HIV infection. The measurement of  Helper T-cell levels has been used to establish decision points for initiating P. jiroveci prophylaxis and antiviral therapy and to monitor the efficacy of treatment. The Public Health Service (PHS) has recommended that Helper T-cell levels be monitored every three to six months in all HIV-infected persons.

The performance characteristics of this test were determined by ARUP Laboratories, Inc.
Note: This assay is designed for enumerating the percents and absolute cell counts of lymphocyte subsets in lysed whole blood.  Whole blood is added to fluorochrome-labeled antibodies that bind specifically to cell surface antigens on lymphocytes.  After incubation, lysing and fixation, percents and absolute counts are enumerated utilizing an internal quantitation standard.  Additional CBC data is not required.

During HIV infection, antiviral therapy is often initiated when the absolute CD4 count drops below 500 cells/µL. When the absolute CD4 count drops below 200 cells/µL, therapeutic prophylaxis against PCP and other opportunistic infections may be initiated. When the absolute CD4 count drops below 100 cells/µL, prophylaxis against Mycobacterium avium complex is recommended.

For longitudinal studies involving serial monitoring, specimen collections should be performed at the same time of day.
CPT Code(s): 86355 B-Cells, Total count; 86357 NK cells, Total count; 86359 T-Cells, Total count; 86360 Absolute CD4 and CD8 counts with ratio
Cross References: T-Cell Immunodeficiency Profile (Lymphocyte Subset Panel 5 - Total Lymphocyte Enumeration)
 
 

 

 

 
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