Saturday, January 12, 2008

Timeline of Immune Restoration with HAART

Excerpted from the abstract of this study (registration required), we find that progress with HAART is exuberant the first four months and dwindles afterwards, and reaches a plateau after three years with many patients never attaining a CD4 count sufficient to overcome immune deficiency.

Methods: A total of 1281 HIV-infected patients initiating HAART were enrolled in the AntiPROtease (APROCO) cohort. We investigated determinants of increase in CD4 count using longitudinal mixed models in patients who maintained a plasma HIV RNA <500>
Results: A total of 870 patients had a virological response at month 4. The median follow-up time was 57 months. Mean estimated increases in CD4 count in patients with persistent virological response were 29.9 cells/µL/month before month 4, 6.4 cells/µL/month between months 4 and 36, and 0.7 cells/µL/month (not significantly different from 0) after month 36. Three factors were associated with a significantly positive CD4 count slope after month 36: male gender (+0.9), no history of antiretroviral therapy at baseline (+1.7) and baseline CD4 count <100>500 cells/µL was achieved in 83% of those with a baseline CD4 count ≥200 cells/µL and in 45% of those with a baseline CD4 count <200>
Conclusion: The increase in CD4 count reaches a plateau after 3 years of virological response. Even if patients initiating HAART with low CD4 counts still show a CD4 count increase after 3 years, it remains insufficient to overcome immune deficiency in all patients.




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