Severe weight loss in HIV / HCV-coinfected patients treated with interferon plus ribavirin: incidence and risk factors.

Weight loss is reported by more than 20% of hepatitis C virus (HCV)-monoinfected patients treated with the peg-interferon (peg-IFN) and ribavirin combination. The aim of this study was to determine the incidence and risk factors of severe weight loss (> or =10%) in human immunodeficiency virus (HIV) / HCV-coinfected patients participating in a randomized, controlled 48-week trial comparing peg-IFN alpha 2b plus ribavirin with IFN alpha-2b plus ribavirin. Univariate and multivariate analyses were used to identify links with antiretroviral treatments, anti-HCV therapy and clinical and laboratory findings. One hundred eleven (28.9%) of 383 patients who received at least one dose of anti-HCV treatment subsequently had severe weight loss. Among patients who took at least 80% of the planned total dose, severe weight loss occurred in 74 patients (32.7%). In multivariate analysis, age >40 years [hazard ratio (HR), 1.59; 95% CI 1.09 to 2.31; P = 0.016], body mass index (BMI) >22 (HR, 1.72; 95% CI, 1.16 to 2.55; P = 0.0069), peg-IFN alpha-2b (HR, 1.82; 95% CI, 1.24 to 2.69; P = 0.0022) and female sex (HR, 1.60; 95% CI, 1.05 to 2.43; P = 0.027) were associated with severe weight loss. In contrast, patients taking non-nucleoside reverse transcriptase inhibitors (NNRTI)-containing antiretroviral regimens were less likely to lose weight (HR, 0.62; 95% CI, 0.39 to 0.96; P = 0.034). Lipodystrophy tended to occur more frequently in patients who had severe weight loss than in the other patients (26.1%vs 17.6%; P = 0.0682) and patients whose weight loss >5% persisted 24 weeks after the completion of anti-HCV therapy (n = 58 / 111) were more likely to be receiving stavudine-based antiretroviral therapy, suggesting that mitochondrial toxicity plays some role in weight loss. These findings show that severe weight loss is a frequent side effect of anti-HCV therapy in HIV / HCV-coinfected patients. The underlying mechanisms remain to be identified.