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HIV Ag/Ab (4th Generation)

HIV Combo Test HIV p24 Antigen/Antibody HIV 1&2 Antibody
Serum (SST) Reactive/Non-reactive

About this test

Fourth-generation combination immunoassay detecting HIV-1 p24 antigen and antibodies to HIV-1/2. Reduces window period to 18–45 days post-exposure. Reactive results require confirmatory testing.

Reference Ranges

Sex Age Range Notes
All All ages See notes Non-reactive or Reactive (confirmatory required if reactive)

Clinical Interpretation

Low / Decreased
Non-reactive with high clinical suspicion — repeat at 45 days post-exposure.
High / Increased
Reactive — early HIV infection (p24 antigen), established HIV infection. Requires confirmatory HIV-1/2 differentiation assay ± viral load.
Specimen
Serum (SST)
Reporting Unit
Reactive/Non-reactive
Category
🦠 Microbiology

⚠ Clinical Note
Reference ranges are indicative. Always interpret results in the context of the individual patient and local laboratory reference intervals, which may vary.