Abstract: Objective The purpose of this study is to investigate the changes of serum interleukin-17A （IL-17A）,fibroblast growth factor （FGF） and IL-7 levels in patients with hepatitis C virus （HCV） infection and to explore the possible mechanism of clearance of viral infection. Methods 70 patients including 52 with chronic hepatitis C and 18 with spontaneous viral clearance of HCV infection were recruited in our hospital between January 2017 and January 2018. 30 healthy persons were selected at the same time in our hospital for control. Serum aspartate aminotransaminase （AST） and alanine aminotransaminase （ALT） levels were detected by automatic biochemical analyzer. Serum anti-HCV antibodies were detected by automatic electrochemiluminescence immunoanalyzer. Serum IL-17A,FGF and IL-7 levels were detected by ELISA,and serum hepatitis C virus RNA loads were detected quantitative detection kits purchased from the United States. Results In our series of patients with chronic hepatitis C,the infected HCV genotypes were mainly type 1b and type 2a,accounting for 67.3% （35/52） and 25.0% （13/52）,respectively;serum ALT and AST levels in patients with chronic hepatitis C were（61.1±50.5） U/L and（57.0±42.8） U/L,respectively,which were significantly higher than those in individuals with spontaneous HCV clearance [（25.0±14.2） U/L and（25.5±9.4） U/L,respectively,P<0.01];serum levels of IL-17A,FGF and IL-7 in patients with chronic hepatitis C were （0.25±0.13） ng/L,（0.51±0.13） ng/L and （0.49±0.12） ng/L, statistically significantly lower than 【（0.75±0.14） ng/L,（0.93±0.11） ng/L and （0.71±0.10） ng/L,respectively,P<0.01】 in individuals with spontaneous HCV clearance,or 【（1.35±0.12） ng/L,（1.49±0.12） ng/L and（0.99±0.12） ng/L,P<0.01】 in healthy persons and there were a significant differences as respect to the three cytokines between patients with spontaneous HCV clearance and healthy persons （P<0.01）. Conclusion In the individuals with spontaneous HCV clearance,serum IL-17A,FGF,and IL-7 levels significantly increased as compared to those in patients with chronic hepatitis C,hinting those cytokines might be involved in the immune response of human body to terminate the hepatitis C viral infection and the mechanisms needs further investigation.

Key words: Hepatitis C, Interleukin-17A, Fibroblast growth factor, Interleukin-7, Spontaneous HCV clearance, Mechanism