Cytokine profile of peripheral blood mononuclear cells from patients with different outcomes of hepatitis C virus infection

Abstract

The relationship between the balance of helper T-cell type 1 (Th1) or type 2 (Th2) cytokines and the clinical course of hepatitis C virus (HCV) infection is unclear. We evaluated Th1 [interleukin (IL)-2, interferon-gamma (IFN-gamma)] and Th2 cytokine (IL-4, IL-10) and 2,5-oligoadenylate synthetase (OAS, an IFN-induced antiviral protein) production by peripheral blood mononuclear cells from 10 healthy anti-HCV-positive individuals (group A), 10 HCV-RNA-positive with persistently normal alanine aminotransferase (ALT) levels (group B), 10 HCV-RNA-positive with abnormal ALT (group C) and 10 uninfected healthy controls. IL-2 production was significantly increased in group B when compared with all the other groups. No difference was found for IFN-gamma. IL-4 was significantly higher in group C than in both group B (P = 0.0006) and controls (P = 0.004). Compared with controls, IL-10 was significantly decreased in group A (P = 0.013) and B (P = 0.004). The production of 2,5-OAS was significantly higher in group B than in A (P = 0.04) and in C (P = 0.004). Finally, in all HCV-RNA-positive patients, a significant correlation was found between ALT and both IL-2 (r = -0.78; P = 0.0008) and IL-4 (r = 0.75; P = 0.0008). (i) subjects who cleared HCV showed a cytokine profile similar to controls; (ii) a preferential shift towards a Th1 profile seems associated with a more favourable clinical outcome in chronic hepatitis C; and (iii) a prevalent Th2 profile seems implicated in HCV pathogenesis and severity of liver disease.