Production of cytokines in patients infected by hepatitis C virus.

T helper type 1 (Th1) cytokines play an important role in antiviral defence. The purpose of this study was to quantify by ELISA IL2, soluble receptor of IL2 (IL2Rs), IFNgamma TNFbeta, IL4, IL6 and IL10 levels in the sera of 134 HCV-positive patients, 69 of whom were coinfected with HIV, and in 54 HIV-HCV-negative patients. The mean IL2Rs and IFN serum levels were much higher in patients with anti-HCV than in the control group, whereas the mean IL4 and IL6 levels were lower in patients infected with HCV. There were no significant differences in cytokine levels between patients with and without HIV. There were significantly less patients with HCV than controls with IFNgamma levels under cut-off, and significantly more patients with HCV with IL4 levels under cut-off. Although serum level of cytokines must be interpreted with caution, the results suggest that Th1 response is enhanced in HCV infection.