Measurement of HIV-1 RNA plasma levels (viral load) provides quantitative measurement of viremia and is used in conjunction with CD4+ T-cell counts. The baseline (pre-treatment) HIV RNA level, combined with the baseline CD4 count, predicts progression to AIDS and death.1,2 Periodic viral load assessment is used to track progression of the infection and is the most important indicator of antiretroviral treatment response. Stable or increasing levels are associated with disease progression and/or treatment failure, whereas decreasing levels indicate therapeutic response. The primary goal of treatment is to decrease the viral load below detectable levels (<48 RNA copies/mL for this quantitative PCR assay), which typically occurs within 12 to 24 weeks.3
Measurement of the HIV RNA level and the CD4 count is recommended at the following intervals: 1) at entry into care; 2) every 3 to 6 months to monitor progression of HIV infection in untreated patients;
3) 2 to 8 weeks after initiation of therapy and every 4 to 8 weeks thereafter until the viral load is below detectable limits; 4) 2 to 8 weeks after changing therapy; and 5) every 6 to 12 months to monitor continuing effectiveness of therapy in stable patients unless new treatment with interferon, corticosteroids, or anti-neoplastic agents is initiated.3 HIV-1 RNA testing is generally not recommended within 4 weeks of immunization or resolution of intercurrent infections.