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Time Sensitive

Ordering Recommendation

Aids in clinical management of HIV-positive individuals.

Mnemonic

ABS4

Methodology

Quantitative Flow Cytometry

Performed

Sun-Sat

Reported

1-2 days

New York DOH Approval Status

Specimens from New York clients will be sent out to a New York DOH approved laboratory, if possible.

Specimen Required

Patient Preparation
Collect

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

CRITICAL ROOM TEMPERATURE.

Unacceptable Conditions

Clotted or hemolyzed.

Remarks

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

Stability

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

Reference Interval

Test Number
Components
Reference Interval
  Absolute CD4
Age 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

Interpretive Data

The CD4 cells are Helper T-cells expressing both CD3 and CD4. CD4 T-cell levels are a criterion for categorizing HIV-related clinical conditions by the 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

Note

This test is specifically designed for enumerating the absolute cell counts of 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, 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

N/A

CPT Codes

86361

Components

Component Test Code* Component Chart Name LOINC
0095854 Absolute CD4 24467-3
* 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.

Aliases

  • Immune Status-Flow Cytometry
  • CD4
  • CD4 Count
  • Helper T-Cell count
  • P. jiroveci prophylaxis determination
Lymphocyte Subset Panel 1 - CD4 Absolute Count Only