Validation of a quantitative RNA PCR assay for HIV‐1 in human plasma

Abstract

A quantitative human immunodeficiency virus type 1 (HIV-1) RNA polymerase chain reaction assay has been validated analytically and clinically in > 13,000 samples. The assay is highly reproducible with intra- and inter-assay precision of 16% and 19%, respectively. In 1,542 of 1,548 subjects with CD4+ counts of 0–500 cells per mm3, viral RNA levels were quantifiable and ranged from ∼ 3,000–52,200,000 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% (0.1 log). Of these patients, 95% 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 high precision and reproducibility of this quantitative RNA PCR assay provide an enhanced means of evaluating therapeutic drug regimens for HIV-1. © 1996 Wiley-Liss, Inc.