07/22/10

PRN Reports From AIDS 2010: When Should HIV Treatment Be Started?

The optimal CD4 count at which to start therapy is still not clear.

The latebreaker presentations today included an investigation of the benefits to starting antiretroviral therapy at different CD4 strata. Joseph Eron from the University of North Carolina at Chapel Hill presented the results from the CASCADE study, a prospective collaborative study that involves 26 cohorts of patients with well-estimated dates of HIV seroconversion.

The investigators used the cohorts to compare those starting antiretroviral therapy to treatment naïve patients within monthly sequential nested subcohorts between 1/1996 and 5/2009. The outcomes measures were time to AIDS and/or death compared in the treatment and treatment naïve groups. The analysis was done using survival analysis and Cox proportional hazards models.

Of the 9,455 patients with 52,268 person-years of follow-up, 812 (8.6%) developed AIDS and 544 (5.8%) died. Antiretroviral therapy was found to reduce AIDS and AIDS-related deaths for those patients with CD4 of ≤350 cells/µL (adjusted HR 0.59, 95% CI: 0.53, 0.81).

Although starting ART at CD4 counts between 350 and 500 cells/µL was also associated with reduced risk, this was not statistically significant; adjusted HR 0.75 (95% CI: 0.49, 1.14). No reduction in risk for any endpoints were noted above CD4 counts of 500 cells/µL. All cause mortality, however, was noted to be lower among those who started ≤500 cells/µL, adjusted HR 0.51 (0.33, 0.80). The greatest protective effect was noted at lower CD4 counts ≤200 cells/µL.

Given these results, there may be benefits to starting ART at higher CD4 counts up to, but not above 500 cells/µL.

Reference:

Funk et al. HAART initiation and clinical outcomes: insights from the CASCADE cohort of HIV-1 seroconverters on 'When to Start'. Presented July 22, 2010 at the XVIII International AIDS Conference, Vienna, Austria. Oral Abstract THLBB201.

Source: Reporting from Vienna, Austria for PRN News: Anita Radix MD, MPH and Susan Weiss FNP, AAHIVS