Objective: To assess the impact of immediate vs. deferred antiretroviral therapy (ART) on CD4 recovery among individuals early in HIV infection.
Design: 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.
Methods: 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.
Results: 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).
Conclusion: 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.