Time Sensitive

Ordering Recommendation

Absolute CD4 count is sufficient for routine HIV monitoring.


Quantitative Flow Cytometry




1-2 days

New York DOH Approval Status

This test is New York DOH approved.

Specimen Required

Patient Preparation

Lavender (EDTA), pink (K2EDTA), or green (sodium or lithium heparin). Hemogard tubes are preferred for laboratory automation and safety.

Specimen Preparation

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

Storage/Transport Temperature


Unacceptable Conditions

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.


EDTA: Ambient: 72 hours; Refrigerated: Unacceptable; Frozen: Unacceptable
Heparin: Ambient: 48 hours; Refrigerated: Unacceptable; Frozen: Unacceptable

Reference Interval

Test Number
Reference Interval
  Absolute CD4
Reference Interval (cells/µL)
0-6 days 1000-4800
1 week-1 month 1500-6000
2-4 months 1600-6500
5-8 months 1000-7200
9-14 months 1300-7100
15-23 months 400-7200
2-4 years 500-2700
5-9 years 400-2500
10-15 years 400-2100
16-64 years 430-1800
65 years or older 490-1600

  % CD4
Age Reference Interval (Percent)
0-6 days 26-62
1 week-1 month 39-69
2-4 months 37-69
5-8 months 27-81
9-14 months 25-86
15-23 months 16-91
2-4 years 25-66
5-9 years 26-61
10-15 years 20-65
16-64 years 32-64
65 years or older 35-68

Interpretive Data

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.

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.

Compliance Category

Modified FDA


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.

Hotline History


CPT Codes



Component Test Code* Component Chart Name LOINC
0095621 Lymphocyte Subset Panel 2 Information 45265-6
0095906 Absolute CD4 24467-3
2012857 % CD4 8123-2
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • CD4
  • CD4 and absoute Count
  • Helper T-Cell level
  • Immune Status-Flow Cytometry
  • P. jiroveci prophylaxis determination
Lymphocyte Subset Panel 2 - CD4 Percent and Absolute