Absolute CD4 count is sufficient for routine HIV monitoring.
Quantitative Flow Cytometry
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.
Clotted or hemolyzed
Specimens must be analyzed within stability times provided. Some medications may affect immunophenotyping results
and should be listed on the patient test request form.
This test is not approved for New York State Clients.
EDTA: Ambient: 72 hours; Refrigerated: Unacceptable; Frozen: Unacceptable
Heparin: Ambient: 48 hours; Refrigerated: Unacceptable; Frozen: Unacceptable
Effective November 16, 2015
Reference Interval Tables:
Pediatric reference values (0 - 6 days up to 10 - 15 years) taken from Scandinavian Journal of Immunology 2012; 75, 436-444.
Adult and Geriatric (16 - 64 and 65 plus years) ranges were developed in-lab.
||1 week - 1 month
||64 years or older
|% CD4||26-62 %||39-69 %||37-69 %||27-81%||25-86%||16-91%||25-66%||26-61%||20-65%||32-64%||35-68%|
|Absolute CD4||1000-4800 cells/µL||1500-6000 cells/µL||1600-6500 cells/µL||1000-7200 cells/µL||1300-7100
|400-7200 cells/µL||500-2700 cells/µL||400-2500 cells/µL||400-2100 cells/µL||430-1800 cells/µL||490-1600 cells/µL|
The CD4 cells are Helper T-cells expressing both CD3 and CD4. CD4 percentage is 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.
Laboratory Developed Test (LDT)
This test is designed for enumerating the percent and absolute cell count of CD4 Helper T-cells 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, percent 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|
|0095621||Lymphocyte Subset Panel 2 Information||45265-6|
- CD4 and absoute Count
- Helper T-Cell level
- Immune Status-Flow Cytometry
- P. jiroveci prophylaxis determination