Lymphocyte Subset Panel 1 - CD4 Absolute Count Only
Also known as: ABS4
Use
The Lymphocyte Subset Panel 1 - CD4 Absolute Count Only test aids in the clinical management of HIV-positive individuals. CD4 cells, also known as Helper T-cells, are a type of white blood cell that express both CD3 and CD4 antigens. These cells are critical in the body's immune response, particularly in the context of HIV infection. Monitoring the absolute count of CD4 T-cells is essential in categorizing HIV-related clinical conditions as per the CDC's classification system. The measurement of CD4 T-cell levels assists in establishing decision points for initiating prophylaxis against P. jirovecii, antiviral therapy, and monitoring the efficacy of HIV treatment. The Public Health Service recommends that CD4 T-cell levels be monitored every 3 to 6 months in all HIV-infected persons.
Special Instructions
This test is specifically designed for enumerating the absolute cell counts of Helper T-cells in lysed whole blood. It is performed in a CLIA certified laboratory for clinical purposes and has not been approved by the FDA. Specimens must be analyzed within specified stability times. Some medications may affect immunophenotyping results; thus, a list of medications should be included on the patient test request form.
Limitations
The test is not approved for New York State clients and requires whole blood specimens to be analyzed within the specified ambient stability times, as refrigerated or frozen storage conditions are unacceptable. Clotted or hemolyzed specimens are also deemed unacceptable. The test performance was determined by ARUP Laboratories, and it has not obtained FDA clearance or approval. The test aids in assessing CD4 levels below critical thresholds for prophylactic interventions, providing crucial data for HIV treatment management, although it does not assess additional CBC data.
Methodology
Cell-based / Cytometry (Flow Cytometry)
Biomarkers
LOINC Codes
- 24467-3
Result Turnaround Time
1-2 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
4 mL
Minimum Volume
0.5 mL
Container
Lavender (EDTA), pink (K2EDTA), or green (sodium or lithium heparin) tubes
Collection Instructions
Collect blood in Hemogard tubes, which are preferred for laboratory automation and safety.
Storage Instructions
Transport specimen at room temperature immediately upon collection.
Causes for Rejection
Clotted or hemolyzed specimens
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | EDTA: 72 hours; Heparin: 48 hours |
| Refrigerated | Unacceptable |
| Frozen | Unacceptable |
Other tests from different labs that may be relevant