Introduction:T-lymphocyte (Th)helper cells are the basic regulating sub-population of the immune system of the organism in defence against different types of viruses incl.the virus of hepatitis C (HCV).The mechanism of their action during chronic HCV infection,however,remains still obscure. Objective:To examine the sub-population of Th-lymphocytes in the peripheral bloodstream and hepatic tissue in patients with chronic viral hepatitis C (CHC)before the beginning of antiviral treatment.Assess the mechanisms of their compartmentalization in hepatic tissue. Method:The method of immunophenotyping and the method of marking intracellular cytokines were used. Results:We proved an increased number of memory CD4+CD45RO+T-lymphocytes in patients with CHC and their localization in hepatic tissue.In the peripheral bloodstream of these patients a predominance of Th1- lymphocytes was found ,producing IFN-gamma as compared with Th2-lymphocytes producing IL-4.A diffe- rence in production of IL-2,TNF-alpha,and IL-10 activated by peripheral Th-lymphocytes between groups of patients with CHC and the control group was not found.In patients with CHC the number of peripheral Th-lymphocytes expressing on their surface the chemokine receptor CXCR3 was increased.Cells with chemo- kine receptors CCR5 or CXCR3 on their surface are found more frequently in hepatic tissue than in the peripheral bloodstream. Conclusion:Based on the assembled results the authors conclude that there is a predominance of memory Th1-lymphocytes producing IFN-gamma in the peripheral blood of patients with CHC and assume that they circulate to the site of inflammation in hepatic tissue via CXCR3 and CCR5 of chemokine receptors.

        Key words: chronic hepatitis C –memory T helper lymphocytes –T-1 helper lymphocytes (Th1)–chemokine receptors CXCR3 and CCR5