Predictive value of HIV-1 RNA detection in plasma by branched DNA assay during long-term zidovudine therapy.

The predictive value of human immunodeficiency virus type 1 (HIV-1) RNA detection in plasma using branched DNA assay was studied in a subgroup of 36 asymptomatic HIV-1-infected patients enrolled in a multicenter, double-blind, randomized study. Patients were randomized to receive either zidovudine (AZT) 1 g/day or placebo and were monitored for a mean time of 61 months. HIV-1 RNA was detected in plasma using branched DNA assay at months 0, 6, 12, 24, and 36. HIV-1 RNA was detected at levels of > or = 10(4) RNA eq/ml (eq/ml) in 8.3% of the patients at baseline, and this percentage increased during the first two years in the placebo group only. The detection rate of HIV-1 RNA at three years was 50% in both the AZT and the placebo groups. HIV-1 RNA levels ranged from 10(4) to 478 x 10(3) RNA eq/ml. HIV-1 RNA was detected at levels of > or = 10(4) eq/ml a mean time of 19 +/- 13 months before progression to AIDS in 76.5% of progressing patients. In a multivariate analysis including baseline CD4+ count, the initial randomization group, HIV-1 RNA detection in plasma, and detection of p24 antigenemia during the first three years of follow-up, the best independent predictors of progression to AIDS at five years and the best independent predictors of death at five years were HIV-1 RNA detection in plasma and p24 antigenemia.