Find Locations
For hours, walk-ins and appointments.HIV p24 Antigen/Antibody With Reflex to Confirmation
CPT:
87389. If reflex testing is performed, concomitant CPT codes/charges will apply.
Synonyms
- HIV Antigen/Antibody
- HIV-1
- HIV-2
- Human Immunodeficiency Virus
- p24
Test Includes
HIV p24 antigen/antibody screen for HIV-1 antibody, HIV-2 antibody, and HIV-1 p24 antigen by EIA; reflex of EIA positive specimens to a HIV-1/HIV-2 antibody differentiation assay; specimens positive by the screening assay but negative by the antibody differentiation assay reflex to HIV-1/HIV-2 RNA testing by qualitative nucleic acid amplification (NAA).
Special Instructions
This test requires a dedicated, unopened, gel-barrier tube or red-top tube sent directly to the testing facility.
This test may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin (also termed as vitamin B7 or B8, vitamin H, or coenzyme R). It is recommended to ask all patients who may be indicated for this test about biotin supplementation. Patients should be cautioned to stop biotin consumption at least 72 hours prior to the collection of a sample.
Expected Turnaround Time
1 - 2 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Related Documents
For more information, please view the literature below.
Human Immunodeficiency Virus 1/O/2 Cascade: Fourth-generation Antigen/Antibody Detection
Specimen Requirements
Specimen
Serum
Volume
2 mL
Minimum Volume
1 mL (Note: This volume does not allow for repeat testing.)
Container
Gel-barrier tube
|
Gel-barrier tube |
|
Gel-barrier tube tube |
Collection
Usual blood collection technique (do not freeze serum gel tubes; send to the lab refrigerated)
Storage Instructions
Refrigerate.
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 7 days (stability provided by manufacturer or literature reference) |
| Frozen | 14 days (stability provided by manufacturer or literature reference) *This stability information is intended for laboratory storage. Do not freeze serum gel tubes; send to the lab refrigerated. |
| Freeze/thaw cycles | Stable x5 (stability provided by manufacturer or literature reference) |
Causes for Rejection
Specimen aliquot; specimen grossly hemolyzed; specimen in container other than those listed; received outside of specimen and/or storage and/or labeling requirements
Test Details
Use
CDC-recommended algorithm for laboratory diagnosis of HIV infection, including acute and primary infection
Limitations
Reactive (repeatedly) specimens must be investigated by additional supplemental tests. A negative test for an individual does not preclude exposure to or infection with HIV-1 and/or HIV-2. Negative results can occur if the quantity of the marker present in the sample is too low for detection by the assay or if the marker is not present during the stage of disease in which a sample is collected.
Methodology
(1) HIV antigen/antibody enzyme immunoassay (EIA) screen for antibodies to HIV-1 and HIV-2 and HIV-1 p24 antigen: Reflex to supplementary differentiation assay; (2) Screen positive with negative antibody typing: Reflex to qualitative nucleic acid amplification (NAA)
References
Association of Public Health Laboratories. Suggested Reporting Language for the HIV Laboratory Diagnostic Testing Algorithm. APHL 2019. APHL Web site. https://www.aphl.org/aboutAPHL/publications/Documents/ID-2019Jan-HIV-Lab-Test-Suggested-Reporting-Language.pdf. Accessed November 2019.
Centers for Disease Control and Prevention. Laboratory testing for the diagnosis of HIV infection : updated recommendations. CDC Stacks Web site. https://stacks.cdc.gov/view/cdc/23447. Accessed November 2019.
Clinical and Laboratory Standards Institute. Criteria for Laboratory Testing and Diagnosis of the Human Immunodeficiency Virus Infection, Approved Guideline. M53-A. Wayne, Pa: CLSI; 2011.
LOINC® Map
© 2025 Laboratory Corporation of America® Holdings. All Rights Reserved.
CPT Statement/Profile Statement
The LOINC® codes are copyright © 1994-2021, Regenstrief Institute, Inc. and the Logical Observation Identifiers Names and Codes (LOINC) Committee. Permission is granted in perpetuity, without payment of license fees or royalties, to use, copy, or distribute the LOINC® codes for any commercial or non-commercial purpose, subject to the terms under the license agreement found at https://loinc.org/license/. Additional information regarding LOINC® codes can be found at LOINC.org, including the LOINC Manual, which can be downloaded at LOINC.org/downloads/files/LOINCManual.pdf