HIV-1/2 Antigen and Antibodies, Fourth Generation, with Reflexes
Also known as: Fourth Generation HIV, 4th Generation HIV
Use
This fourth-generation HIV‑1/2 antigen and antibody combination assay enables detection of acute HIV‑1 infection via p24 antigen as well as established infection through HIV‑1 and HIV‑2 antibodies. It is compliant with the current CDC‑recommended diagnostic algorithm for HIV infection detection and reflexive confirmatory pathway. Reactive results on the initial screen reflex to HIV‑1/2 antibody differentiation and, if differentiation is negative or indeterminate, further reflex to HIV‑1 RNA qualitative PCR testing to confirm infection status.
Special Instructions
Reflex testing: if the primary Ag/Ab screen is repeatedly reactive, HIV‑1/2 antibody differentiation is performed; if that result is negative or indeterminate, then HIV‑1 RNA qualitative real‑time PCR is performed, each at additional charge. This assay aligns with guidelines for screening and diagnostic confirmation.
Limitations
The fourth‑generation Ag/Ab assay may detect passively transferred maternal antibodies and is therefore not appropriate for infants younger than 2 years of age. Detection window: half of patients become repeatedly reactive within 18 days post‑infection and over 99% react within 45 days; infection cannot be reliably excluded before 45 days after exposure.
Methodology
Immunoassay (Multiplex Protein Panel)
Biomarkers
Result Turnaround Time
Not provided.
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
3.0 mL
Minimum Volume
2.0 mL
Container
Serum separator tube (gel‑barrier) preferred; red‑top tube (no gel) acceptable
Collection Instructions
For serum: collect in serum separator or red‑top tube, invert, clot for 30 minutes, centrifuge, separate. For red‑top, transfer to plastic screw‑cap vial. For EDTA plasma: collect in EDTA tube, invert, centrifuge, separate plasma within 2 hours, aliquot.
Storage Instructions
Spun serum separator tubes may be submitted at room temperature or refrigerated unopened; red‑top serum transferred to plastic screw‑cap vial.