Association of baseline CD4+ cell count and HIV-RNA on sustained virologic response to interferon-ribavirin in HIV/HCV coinfected patients

Background and rationale for the study. We assessed the association of CD4+ T-cell counts and HIV-RNA on sustained viral response (SVR) after therapy with pegylated interferon and ribavirin (PR) in HIV/HCV coinfected patients. We examined two large cohorts of coinfected patients treated with PR in Spain between 2000 and 2008. SVR was defined as undetectable HCV-RNA at 24 weeks after the end of PR. Results. We studied 1682 patients, of whom 38% achieved SVR. Baseline factors independently associated with reduced odds of SVR included genotype 1 or 4, HCV-RNA > 500,000 IU/mL, advanced liver fibrosis, CDC clinical category C, and detectable HIV-RNA. By multivariate logistic regression analysis, we found that, in comparison with patients with combination antiretroviral therapy (cART) and undetectable HIV-RNA, the odds ratio [95% confidence interval (CI)] of SVR was 0.56 (0.41-0.78) for cART and detectable HIV-RNA, 0.86 (0.56-2.57) for no-cART and detectable HIV-RNA, and 1.38 (0.74-2.57) for no-cART and undetectable HIV-RNA. Conclusions. Detectable HIV-RNA, but not CD4+ T-cell count, was associated with reduced odds of SVR. However, this finding was only confirmed for cART and detectable HIV-RNA, raising the question as whether this represents a true association of HIV-RNA on response to PR or a spurious association due to poor adherence to treatment.