The HIV-1 viral load assay quantifies HIV-1 RNA in the plasma of HIV-1 infected individuals. Result of HIV-1 RNA testing are reported in copies/mL and/or International Units/mL (IU/mL). Results reported in IU/mL can be compared between laboratories independently which platform was used to obtained results.
Normal range: Not detected when the result is below the level of detection of the assay.
Use
Methods
Branched DNA assay (bDNA; Siemens): A signal amplification technology that detects the presence of specific nucleic acids by measuring the signal generated by branched, labeled DNA probes; a reliable method that provides consistent results in the higher range of the assay.
Real-time PCR (Cobas AmpliPrep/Cobas TaqMan, Roche): Reverse transcription is followed by PCR amplification and quantification of the targeted DNA molecule; generally offers both a wider range of quantification and a lower limit of detection than the bDNA method.
Used in the management of HIV-1 " “infected individuals undergoing antiviral therapy.
Limitations
PCR inhibitors in the specimen may lead to underestimation of viral quantitation or false-negative results in rare cases.
For consistency in interpretation of patient results, the same methodology should be used in patient management.