Abstract. The main objective of this work was to identify allelic variants of cytokine genes at the polymorphic positions of G-308A TNFА, T-330G IL-2, С-590Т IL-4, С-703Т IL-5, and C-592A IL-10, and to assess their contribution to predisposition and resistance of human patients to progression of viral hepatitis C infection. We observed significant increase in frequency of T/G T-330G IL-2 genotype in HCV-infected patients, as compared to healthy individuals. Distribution analysis of C-590T promoter alleles of the IL-4 gene displayed a wide overrepresentation of C/T genotype among HCV-infected patients. Likewise, we have shown the G/A genotype of G-308A TNFA to be highly frequent in the group of HCV-infected patients, whereas this genotype was rare in the sample of healthy persons. When analysing allelic frequencies of cytokine genes at these polymorphic positions, we get an opportunity to predict predisposal for the chronic variant of viral hepatitis C in HCV-infected persons.

Abstract. The main objective of this work was to identify allelic variants of cytokine genes at the polymorphic positions of G-308A TNFА, T-330G IL-2, С-590Т IL-4, С-703Т IL-5, and C-592A IL-10, and to assess their contribution to predisposition and resistance of human patients to progression of viral hepatitis C infection. We observed significant increase in frequency of T/G T-330G IL-2 genotype in HCV-infected patients, as compared to healthy individuals. Distribution analysis of C-590T promoter alleles of the IL-4 gene displayed a wide overrepresentation of C/T genotype among HCV-infected patients. Likewise, we have shown the G/A genotype of G-308A TNFA to be highly frequent in the group of HCV-infected patients, whereas this genotype was rare in the sample of healthy persons. When analysing allelic frequencies of cytokine genes at these polymorphic positions, we get an opportunity to predict predisposal for the chronic variant of viral hepatitis C in HCV-infected persons.

Immunopathogenesis of chronic viral hepatitides was studied by modern immunological, molecular, genetic methods. We revealed an imbalance in the production of immunoregulatory cytokines by mononuclear leukocytes (primarily of the Th2 type). The risk of progression and chronic course of viral hepatitides in Caucasian population was associated with alleles of promoter regions −330G and −592A in the IL-2 and IL-10 genes, respectively, as well as with the T/T genotype of the polymorphic region C590T in the IL-4 gene. The C/C genotype of the IL-10 gene promoter region C592A was shown to be a factor determining resistance to long-term persistence of hepatitis B and C viruses.