Abstract: Objective To investigate the changes of peripheral blood Th17 and Treg cells and their related serum cytokines in patients with chronic hepatitis C（CHC） and liver cirrhosis（LC）. Methods 33 patients with CHC, 27 with CHC-induced LC patients and 30 healthy persons were recruited in this study between October 2014 and October 2016. The patients with CHC received PR therapy for 12 months. The percentages of peripheral blood Th17 and CD4⁺CD25⁺Foxp3⁺Treg cells and serum interleukin-6（IL-6）,IL-10,IL-17 and transforming growth factor-β （TGF-β） were detected by FCM and ELISA respectively. Results The percentages of Th17 and Treg cells and the Th17/Treg ratio in patients with LC were （4.6±0.7）%,（2.7±0.5）% and （1.6±0.4）,and in patients with CHC were （5.8±0.9）%,（3.1±0.6）% and （1.9±0.5）, both significantly higher than（2.3±0.4）%,（1.7±0.4）% and（1.4±0.2） in healthy control （P<0.05）,and the percentages of Th17 and Treg cells and the Th17/Treg ratio in patients with LC were significantly higher than those in patients with CHC （P<0.05）;serum levels of IL-6, IL-10,IL-17 and TGF-beta in patients with LC were（9.9±2.5） ng/L,（18.0±3.2） ng/L,（15.3±2.8） ng/L and （5.5±0.8） ng/L and in patients with CHC were （14.1±3.0） ng/L,（21.4±4.0） ng/L,（23.3±3.9） ng/L and （7.2±1.2） ng/L,both significantly higher than （6.7±1.1） ng/L,（14.2±2.9） ng/L,（5.3±0.6） ng/L and （4.3±1.0） ng/L in healthy persons（P<0.05）,and serum IL-6,IL-10,IL-17 and TGF-β levels in patients with LC were significantly higher than those in patients with CHC（P<0.05）;the percentages of Th17 and Treg cells,and serum TGF-β,IL-10 and IL-17 levels in patients with CHC at the end of the treatment weere （3.4±0.6）% and （1.9±0.4）%,and （4.7±0.6） ng/L,（15.1±2.5） ng/L and（11.5±2.1） ng/L,all significantly lower than those before treatment（t=7.477,t=7.177,t=4.596,t=4.102,t=6.237,P<0.05）. Conclusion The blood Th17 and Treg cell numbers and their related serum cytokines in patients with CHC and LC increase,which might be closely related to the pathogenesis of hepatitis C viral infection. The surveillance of the regulatory T lymphocytes and cytokines might be helpful in evaluating antiviral therapy.

Key words: Liver cirrhosis, Hepatitis C, Helper T lymphocytes 17, Regulatory T lymphocytes, Cytokines