Tissue and serum immune response in chronic hepatitis C with mild histological lesions

The immunopathogenesis of chronic hepatitis C virus (HCV) infection is a matter of great controversy and has been suggested to involve a complex balance between cytokines with pro and anti-inflammatory activity. We investigated the expression of inflammatory cells and cytokines in the liver and serum of 51 chronically HCV infected patients and compared them to data from two sets of normal controls: 51 healthy blood donors and 33 liver biopsies of healthy liver donors. We also assessed the relationship between selected cytokines and cell populations in hepatic compartments and the disease stage. Compared with controls, hepatitis C patients had a greater expression of portal TNF-α, TGF-β and CD4⁺ and acinar IFN-γ, TNF-α, IL-1β and IL-4, as well as a higher serum concentration of IL-2, IL-10 and TGF-β. Significant positive correlations were found between portal CD4⁺ and TNF-α, portal CD8⁺ and TGF-β, portal CD45⁺RO and TNF-α, acinar CD45⁺RO and IFN-γ and acinar CD57+ and TGF-β. In conclusion, we have shown that (i) in this sample of predominantly mild disease, the immune response was associated with a proinflammatory response pattern, (ii) CD4⁺ T-lymphocytes played a major role in orchestrating the immune response and (iii) these events primarily took place in the portal space.

Keywords
chronic hepatitis C - cytokines - immunohistochemistry - physiopathology of chronic hepatitis C - T-lymphocytes