Cytokine serum levels in patients with chronic HCV infection

The pathogenic role of immune-mediated mechanisms in chronic hepatitis C virus (HCV) infection has not yet been elucidated. In this study, we report different cytokine expression profiles from hemodialysis (HD) and non-HD HCV (+) patients. IL-1β, IL-2, IL-4, IL-6, TNF-α, and TGF-β1 serum levels, and liver biochemical parameters were determined in 85 individuals (41 HD patients and 44 non-HD patients). Screening for HCV RNA and anti-HCV antibodies was performed using qualitative and quantitative reverse transcription polymerase chain reaction (RT-PCR), and standardized enzyme-linked immunosorbent assay (ELISA) and recombinant immunoblot assay (RIBA) methods, respectively. IL-4 and IL-1β demonstrated decreased serum levels in non-HD HCV carriers compared with healthy controls. Both T helper (Th) 1 and Th2 lymphocytes were highly associated with chronic HCV infection, as indicated by the increased IL-2, IL-4, and IL-6 cytokine circulating levels in all chronic active hepatitis (CAH) patients examined. An enhanced Th2 response (IL-4 and IL-6) coupled with increased TNF-α and IL-1β serum levels was reported in HD HCV (–) patients. In conclusion, our data show that a virus-induced Th2 and IL-1β immunosuppression is an early event in HCV-related chronicity. Long-term HD specifically exerts a chronic effect on IL-6, IL-1β, and TNF-α serum circulating levels. Irrespective of the HD status, HCV viremia, and liver biochemistry parameters, both Th1 and Th2 responses are highly associated with chronic HCV infection. J. Clin. Lab. Anal. 16:40–46, 2002. © 2002 Wiley-Liss, Inc.