It is well known that highly active antiretroviral therapy (HAART) suppresses HIV and leads to immunological rebound, but the magnitude of CD4 cell gains has not been well characterized outside the highly structured setting of a clinical trial.

As reported in the March 2008 issue of AIDS Research & Human Retroviruses, investigators analyzed the patterns of CD4 cell count and plasma viral load changes in 170 treatment-naive HIV positive individuals who initiated HAART between 1997 and 2003. Immunological success (an increase of > 50 CD4 cells/mm3) was evaluated using Kaplan-Meier survival analysis and Cox proportional hazard models.

A large majority of participants -- 80% -- experienced a confirmed CD4 cell count increase of more than 50 cells/mm3 after HAART initiation. Multivariate analysis showed that patients with a pre-HAART viral load of 100,000 copies/mL or greater were more likely to achieve immunological success compared to those with a lower viral load, "suggesting that individuals with the highest HIV viral load levels may benefit the most from HAART initiation," the study authors wrote.

They added that, "Future studies of immunological rebound are warranted to further define and characterize immune responses to HAART in diverse populations in order to optimize guidelines for initiation of treatment and assessment of successful responses."

4/18/08

Reference
JT Blackard, SL Welles, A Ackerman, and others. Immunological rebound after initiation of highly active antiretroviral therapy in treatment-naive patients. AIDS Res Hum Retroviruses 24(3): 499-504. March 2008.