RAPID AND PRECISE QUANTIFICATION OF HIV-1 RNA IN PLASMA USING A BRANCHED DNA SIGNAL AMPLIFICATION ASSAY

The level of human immunodeficiency virus type 1 (HIV-1) RNA in human plasma has been quantitated directly with use of a solid-phase nucleic acid hybridization assay, based on branched DNA (bDNA) signal amplifi cation technology with chemiluminescent detection. Signal amplificatio n is accomplished by the incorporation of sites for 1,755 alkaline pho sphatase-labeled probes per genome of HIV-1, after successive hybridiz ation of target-specific oligonucleotides and bDNA amplifier molecules , The assay is performed in microwells, much like an immunoassay, and is amenable to routine laboratory use, Reproducibility and specificity studies indicated that the bDNA method was precise and showed no reac tivity with seronegative donors. HIV-1 RNA levels were quantitated for 348 seropositive specimens, with a detection rate of 83% for those sp ecimens from patients with <500 CD4(+) T-cell counts. Plasma RNA level s were found to change with disease stage, and in response to antivira l therapy, Quantitation of HIV-1 RNA in the plasma of HIV-1-infected p atients, with use of the bDNA assay, may be a useful method for monito ring HIV-1 disease progression and therapeutic response.