Clinical progression of HIV-1 infection according to the viral response during the first year of antiretroviral treatment

Objective: To compare HIV-disease progression according to changes of plasm a HIV RNA observed in the year following initiation of a new antiretroviral treatment. Design: Prospective cohort treated with two nucleoside analogues or a tripl e combination including a protease inhibitor. Methods: A Cox model was used to estimate the effect of viral response duri ng the first year after initiation of treatment on the subsequent occurrenc e of new AIDS-defining events or death. Viral response was fitted either as HIV RNA reduction during the initial 4-12 months of treatment or reduction during the first month. Results: Among 773 patients (47% with triple drug combination) followed for a median period of 27 months, 62 patients experienced a clinical event. Po or viral responders (at least two measurements > 3.7 log(10) copies/ml duri ng 4-12 months of treatment) had a higher risk of disease progression than good responders (RNA < 2.7 log(10) copies/ml) after adjustment [hazard rati o (HR), 2.24; 95% confidence interval (Cl), 1.17-4.29]. Intermediate respon ders (2.7 less than or equal to RNA less than or equal to 3.7 log(10) copie s/ml) had a risk of progression comparable with that of good responders (HR , 1.43; 95% Cl, 0.64-3.22). A large initial viral reduction was also a prot ective factor for clinical progression (HR, 0.51 for 1 log(10) copies/ml in crease of the reduction; 95% Cl, 0.31-0.85) and was associated with the vir al response during the subsequent 4-12 month period. No patient with a redu ction < 0.5 log(10) copies/ml in the first month was classified as a good r esponder in the subsequent 4-12 month period (P < 0.01). Conclusions: A sustained HIV RNA > 3.7 log(10) copies/ml should suggest a p rompt change of treatment. When the reduction in HIV RNA is < 0.5 log(10) a fter 1 month of treatment, this action should be anticipated. A sustained H IV RNA level between 2.7 and 3.7 log(10) copies/ml may permit the deferral of a change of drug regimen according to the patient's history and therapeu tic options. (C) 2000 Lippincott Williams & Wilkins.