Absolute CD4 count is sufficient for routine HIV monitoring.
Quantitative Flow Cytometry
New York DOH Approval Status
Lavender (EDTA), pink (K2EDTA), or green (sodium or lithium heparin). Hemogard tubes are preferred for laboratory automation and safety.
Transport 4 mL whole blood. (Min: 0.5 mL)
CRITICAL ROOM TEMPERATURE.
BAL specimens (refer to ARUP test code 0093420). Clotted or hemolyzed specimens.
Specimens must be analyzed within stability times provided. Some medication may affect immunophenotyping results and should be provided on the patient test request form.
EDTA: Ambient: 72 hours; Refrigerated: Unacceptable; Frozen: Unacceptable
Heparin: Ambient: 48 hours; Refrigerated: Unacceptable; Frozen: Unacceptable
New York State Clients: Same as the above.
The CD4 cells are Helper T-cells expressing both CD3 and CD4. The CD8 cells are Cytotoxic T-cells expressing both CD3 and CD8. CD3, CD4 and CD8 percentages are reported as a percent of total lymphocytes. CD4 T-cells levels are a criterion for categorizing HIV-related clinical conditions by CDC's classification system for HIV infection. The measurement of CD4 T-cell levels has been used to establish decision points for initiating P. jirovecii prophylaxis, antiviral therapy and to monitor the efficacy of treatment. The Public Health Service (PHS) has recommended that CD4 T-cell levels be monitored every 3 to 6 months in all HIV-infected persons.
This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.
This test 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.
|Component Test Code*||Component Chart Name||LOINC|
|0095616||Lymphocyte Subset Panel 4 Information||48767-8|
- CD3 and CD4
- Helper T-cell count
- Immune Status-Flow Cytometry
- P. jiroveci prophylaxis determination
- T-Cell Immunodeficiency Short Profile