The role of serum Th1 and Th2 cytokines in patients with chronic hepatitis B and hepatitis C virus infection

Abstract

Background. The imbalance of pro-inflammatory Th1 and anti-inflammatory Th2 cytokine production may play an important role in the immunopathogenesis of hepatitis B and C virus infection. The aim of this study was to analyze serum levels of Th1 and Th2 cytokines in patients with chronic hepatitis virus infection of different etiology. Materials and methods. The serum levels of Th1 cytokines: interferon-gamma (IFN-γ), interleukin-2 (IL-2), soluble IL-2 receptors (sIL-2R), and a Th2 cytokine, interleukin-10 (IL-10) were measured by EIA assay in 20 healthy controls and in 62 patients (47 males and 15 females, mean age 26.0 years) with chronic hepatitis virus infection according to the etiology: 15 patients with hepatitis B, 21 patients with hepatitis C and 26 patients with mixed hepatitis (B + C). The levels of the cytokines were compared with the traditional biochemical (alanine transaminase, ALT) and viral (HBV DNA or HCV RNA) indicators of infection. Results. Apart from etiology, the serum levels of IFN-γ, sIL-2R and IL-10 cytokines were higher in patients with chronic hepatitis B and/or C than those in the healthy controls (P < 0.05). The sIL-2R and IL-10 levels were significantly correlated with ALT activity, although there was no correlation between the mentioned cytokines and the presence of HBV DNA or HCV RNA. However, the levels of IL-2 were significantly lower only in cases of chronic HCV monoinfection, while they were close to normal in chronic hepatitis B and in mixed hepatitis. The mean levels of sIL-2R tended to be increased in the cases of chronic hepatitis B, hepatitis C and mixed hepatitis, but the differences were not statistically significant. Conclusion. Amongst the Th1 and Th2 cytokines studied, sIL-2R, IFN-γ and IL10 co-participate in the pathogenesis of chronic hepatitis B or C and can be used for evaluating the immune state of the organism. Our data suggest that sIL-2R is closely related with the severity of the pathological process of liver lesions.