Context: There is little information available on the correlation between HIV-1 RNA level, CD4 cell count and the risk of progression to AIDS or death during treatment with reverse transcriptase inhibitors.
Objectives: To define the correlation between HIV-1 RNA level, CD4 cell count and the 1 year risk of progression to AIDS or death.
Design: Pooled analysis of six randomized clinical trials of zidovudine/lamivudine versus control treatments.
Setting: Investigational sites in Europe, North America, Australia and South Africa.
Patients: The trials recruited 1488 adult HIV-1-infected male and female patients aged > or = 18 years, with inclusion CD4 cell count between 25 and 500 x 10(6) cells/l. Patients were either nucleoside analogue-naive or pre-treated, and at all stages of HIV-1 disease.
Main outcome measures: : Progression (defined as all new and recurrent AIDS-defining events or death) was correlated with the HIV-1 RNA level and CD4 cell count during the first 8 to 52 weeks of treatment.
Results: During a median 1 year follow up, progression was largely restricted to patients with both low CD4 cell count (< or = 200 x 10(6) cells/l) and high HIV-1 RNA level (> 5000 copies/ml). There was an increase in the incidence of progression events with rises in HIV-1 RNA level > 5000 copies/ml and reductions in CD4 cell count under 200 x 10(6) cells/l. The events occurring with HIV-1 RNA < 5000 copies/ml were generally atypical.
Conclusions: Progression to AIDS or death is rare for patients with HIV-1 RNA < or = 5000 copies/ml, particularly when CD4 cell count is more than 200 x 10(6) cells/l.