To assess the impact of immediate vs. deferred antiretroviral therapy (ART) on CD4+ recovery among individuals early in HIV infection.
Using serologic markers of early infection together with self-reported dates of infection and HIV diagnosis, ART-naive participants who were randomized to immediate vs. deferred ART in the Strategic Timing of Antiretroviral Treatment trial were classified into subgroups of duration of HIV infection at baseline. CD4+ cell count recovery over follow-up according to duration of HIV infection was investigated.
Three subgroups were defined: first, infected 6 months or less (n = 373); second, infected 6–24 months (n = 2634); and third, infected 24 months or longer (n = 1605). Follow-up CD4+, CD8+, and CD4+ : CD8+ ratio for the immediate and deferred ART groups were compared by subgroup using linear models. For the deferred ART group, decline to CD4+ less than 350 cells/μl or AIDS according to infection duration was compared using time-to-event methods.
Follow-up CD4+ cell count differences (immediate minus deferred) were greater for those recently infected (+231 cells/μl) compared with the two other subgroups (202 and 171 cells/μl; P < 0.001). CD4+ : CD8+ ratio treatment differences varied significantly (P < 0.001) according to duration of infection. In the deferred ART group, decline to CD4+ less than 350 cells/μl or AIDS was greater among those recently infected (16.1 vs. 13.2 and 10.5 per 100 person years for those infected 6–24 and ≥24 months; P = 0.002).
In this randomized comparison of immediate vs. deferred ART, the CD4+ cell count difference was greatest for those recently infected with HIV, emphasizing the importance of immediate ART initiation.