Rate of CD4+ Cell Count Increase over Periods of Viral Load Suppression: Relationship with the Number of Previous Virological Failures

Abstract

Background. Although the kinetics of CD+ cell counts have been extensively studied in antiretroviral-naive HIV-infected patients, data on individuals who have failed combination antiretroviral therapy (cART) are lacking. Methods. This analysis was based on the ICONA Foundation Study. Subjects with ≥1 episode of viral suppression after starting first-line cART were included (np3537). Following a viral rebound, patients who achieved another episode of viral suppression could reenter the analysis. The percentage of patients with an increase in CD+ cell count 1300 cells/mm3 was estimated using Kaplan-Meier techniques; the rate of CD+ cell count increase per year was estimated using a multivariable, multilevel linear model with fixed effects of intercept and slope. Multivariable models were also fitted to include several covariates. Results. The median time to reach a CD+ cell count increase <300 cells/mm3 from baseline was significantly associated with the number of failed regimens: 34 months, 41 months, 51 months, and 45 months in subjects without evidence of previous virological failure, or 1, 2, or ≥3 previous virologically failed regimens, respectively (P