A quantitative human immunodeficiency virus type 1 (HIV-1) RNA polymerase chain reaction assay has been validated analytically and clinically in over 13,000 samples. The assay is highly reproducible with intra-and inter-assay precision of 16 and 19%, respectively. In 1542 of 1548 subjects with CD4 + counts of 0-500 cells per mm3, viral RNA levels were quantifiable and ranged from about 3000- 52,200,000 copies per milliliter. Median plasma HIV-1 RNA values were inversely proportional to CD4 + counts from 0-400 cells per mm3. When patients were off antiretroviral therapies for 14 days prior to the initial baseline RNA PCR evaluation, the mean variance between the two baseline values was 23%. Ninety-five percent of these patients had a sufficient plasma viral load to quantitate a 10 fold (1 log) diminution in viral load caused by antiviral therapy. In contrast, only 20% and 45% of these subjects had sufficient p24 and ICD p24 levels to detect a 50% diminution in circulating virus. The assay has been shown to correlate well with the Roche Biomedical RNA PCR assay (r(2)=.869) using samples from 20 patients at 6 timepoints. The high precision and reproducibility of this quantitative RNA PCR assay provide an enhanced means of evaluating therapeutic drug regimens for HIV-1.

CD4 Lymphocyte Count HIV Core Protein p24/BLOOD HIV Infections/DRUG THERAPY/*VIROLOGY HIV-1/GENETICS/*ISOLATION & PURIF Human Polymerase Chain Reaction RNA, Viral/*BLOOD Reproducibility of Results ABSTRACT

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