Cautions

This test is not licensed by the US Food and Drug Administration (FDA) as a screening test for HIV-1 infection in donors of blood, human cells, tissues, or tissue products.

Although this quantitative HIV-1 RNA test is not FDA-approved for diagnostic purposes, the US Department of Health and Human Services Panel on Antiretroviral Therapy and Medical Management of HIV-Infected Children recommends the use of molecular-based assays to detect HIV-1 RNA or proviral DNA for the diagnosis of HIV infection in infants under 2 years and born to HIV-infected mothers.

A single HIV-1 viral load test result should not be used as the sole criterion in guiding therapeutic decisions and intervention in the clinical care of individuals living with HIV-1. Viral load results should be correlated with patient symptoms, clinical presentation, and CD4 cell count. Due to the inherent variability in the assay, physiologic variation, and concurrent illnesses in the infected patients, less than 100-fold (<2 log) changes in HIV-1 viral load should not be considered significant changes.

Viral load results of less than 20 copies/mL do not necessarily indicate absence of HIV-1 viral replication. Inhibitory substances may be present in the specimen, leading to negative or falsely low HIV-1 RNA results. Improper specimen collection or storage may lead to negative or falsely lower viral load results.

Although this commercial HIV-1 viral load assay is optimized for quantification of viral load in HIV-1 infection due to HIV-1 groups M (subtypes A to H) and O strains, results generated from HIV-1 group O strains may be discordant (≥ 0.5 log copies/mL) with those obtained from other commercially available HIV-1 viral load assays. The assay is not reliable for quantifying viral loads in infection caused by HIV-1 group N and HIV-2 strains.

ACD plasma specimens are not optimal for HIV-1 viral load testing because such specimens show HIV-1 RNA levels that are approximately 15% lower than those collected in tubes containing EDTA. Plasma specimens stored frozen in plasma preparation tubes (PPT) are not suitable for HIV-1 viral load testing due to falsely high viral load results from release of intracellular HIV-1 nucleic acids (DNA and RNA) during the freezing process.

Due to the potential cross-reactivity between some nucleic acid testing assays and certain lentiviral vector-based CAR T-cell therapies, clinicians should exercise caution when ordering and interpreting HIV testing in patients who have received CAR-T cell therapy. Some lentiviral CAR-T vectors contain a target region of the test, which can lead to false-positive HIV-1 results.