Rapid clearance of virus after acute HIV-1 infection: correlates of risk of AIDS

Abstract

Objective: Our objective was to define early virologic and immunologic determinants of human immunodeficiency virus (HIV) type 1 disease progression among 22 case subjects with acute infection from the Trinidad Seroconvertor Cohort.

Methods: A linear segmented regression model was fitted to sequential quantitative virus load measurements. Parameters of virus kinetics during different phases of primary infection were correlated with clinical and immunologic end points, by use of Kaplan-Meier estimates and Cox regression.

Results: Ten individuals developed acquired immunodeficiency syndrome (AIDS)-defining events. In univariate analysis, progression to AIDS was associated with rate of initial HIV clearance (P=.002), virus load during set point (P=.008), and CD4(+) cell count during steady state (P=.04). In the multivariate analysis, a rapid rate of initial clearance was the sole independent predictor of subsequent progression to AIDS and was associated with a 92% reduction in the risk of AIDS. The rate of initial clearance is inversely correlated with the number of early symptoms (r=-0.66; P=.0008). However, symptoms did not predict subsequent risk of AIDS.

Conclusion: Among a subset of patients, rapid clearance of plasma HIV-1 after peak viremia is associated with lower viral set point, prolonged virus suppression before loss of virologic control, and decreased risk of AIDS. These findings are consistent with the hypothesis that effective immune responses during the earliest phase of infection are important determinants of the subsequent natural history.