Slower CD4 cell decline following cessation of a 3 month course of HAART in primary HIV infection: findings from an observational cohort

Objective: To investigate the effect of a short course of HAART during primary HIV infection (PHI) on rate of CD4 cell and viral load change. Methods: Data following HAART cessation from 89 individuals (seroconverting 1999-2003) who chose to take a 3 month course of HAART at PHI were compared with 179 untreated controls in CASCADE, using linear and nonlinear random effects models. Participants were non-randomized but frequency matched for age, sex, risk factor, year of seroconversion and presentation within the first 6 months of seroconversion. Time to CD4 cell count < 350 cells/mu l and initiation of clinically indicated antiretroviral therapy (ART) were also compared as competing risks. Results: The rate of CD4 cell decline following therapy cessation appeared significantly slower among treated participants than untreated controls: losses of 51 cells/mu l [95% confidence interval (CI), 32-69] and 77cells/mu l (95% Cl, 65-89), respectively, 3 years after seroconversion (P = 0.011). Based on extrapolated data, viral loads also differed significantly at this point (4.09 and 4.53 copies/ml, respectively). At 2 years, there was no significant difference in mean viral load levels: 4.31 copies/ml (95% Cl, 4.14-4.48) and 4.47 copies/ml (95% Cl, 4.28-4.66), respectively. CASCADE seroconverters were more likely to reach CD4 cell count < 350 cells/mu l or initiate clinically indicated ART (hazard ratio, 1.45; 95% Cl, 1.02-2.05; P=0.039). Conclusion: A short course of ART at PHI may delay CD4 cell decline. Confirmation of this requires a randomized clinical trial powered to address definitively the role of ART intervention in PHI (currently underway through SPARTAC). (C) 2007 Lippincott Williams & Wilkins.