CD4+ T-cell percentage is an independent predictor of clinical progression in AIDS-free antiretroviral-naive patients with CD4+ T-cell counts >200 cells/mm3

Abstract

Background: The aim of this study was to evaluate the clinical prognostic value of the CD4+ T-cell percentage (%CD4), the CD4+/CD8+ T-cell ratio or the CD8+ T-cell count, in addition to the CD4+ T-cell count and viral load (VL) in antiretroviral-naive HIV-infected patients with CD4+ T-cell counts >200 cells/mm(3).

Methods: Antiretroviral-naive patients (n=9,740) who were AIDS-free and had a CD4+ T-cell count >200 cells/mm(3) at their first visit after January 1997 were followed-up until treatment initiation or clinical progression (mean follow-up 17 months and 13,660 person-years). Poisson regression was used for statistical analyses.

Results: Progression to AIDS-defining events (ADEs), serious ADEs and death occurred in 228 patients (crude rate 1.69 per 100 person-years), 105 patients (0.77 per 100 person-years) and 67 patients (0.49 per 100 person-years), respectively. Regarding progression to ADE, the data fit was improved when the model also included the %CD4 (Akaike's information criteria [AIC] 2,049) and, to a lesser extent, the CD4+/CD8+ T-cell ratio (AIC 2,053), in addition to CD4+ T-cell count and VL (AIC 2,056). After adjustment for VL and baseline characteristics, patients with CD4+ T-cell counts of 350-500 cells/mm(3) and %CD4<15% had an estimated incidence of ADE of 3 per 100 person-years, similar to that in patients with CD4+ T-cell counts of 200-350 cells/mm(3) and %CD4>15%. The %CD4 was also significantly associated with the risk of serious ADE. By contrast, %CD4, CD4+/CD8+ T-cell ratio or CD8+ T-cell count had no additional prognostic value for the risk of death.

Conclusions: In antiretroviral-naive HIV-infected patients with CD4+ T-cell counts >200 cells/mm(3), the %CD4 was predictive of the risk of clinical progression independently of CD4+ T-cell count and VL.