Abstract: Objective To investigate serum IL-17 and its gene polymorphism in clinical outcomes of individuals with chronic hepatitis B viral infection. Methods 40 patients with hepatitis B liver cirrhosis, 120 patients with chronic hepatitis B,60 patients with asymptomatic HBV carriers and 80 individuals with self-limited HBV infection were rucruited in this study between March 2015 and August 2017. Serum IL-17 levels were detected by ELISA,serum alanine aminotransferase（ALT）,aspartate aminotransferase（AST） and total bilirubin （TBIL） levels were detected by automatic biochemical analyzer. Serum HBV DNA load was detected by polymerase chain reaction with fluorescent probe,and the single nucleotide detection kit was used for polymorphism detection. Results Serum level of IL-17 in patients with hepatitis B liver cirrhosis was higher than in patients with chronic hepatitis B,asymptomatic HBV carrier or self-limited HBV infection（F_3,296=102.8,P<0.05）; serum IL-17 level in patients with chronic hepatitis B was significantly higher than in asymptomatic HBV carrier or self-limited HBV infection（P<0.05）;in patients with hepatitis B liver cirrhosis,serum IL-17 level increased in those with higher serum HBV DNA load（t=5.1,P<0.05） and high ALT level（t=10.7,P<0.05）;in both patients with hepatitis B liver cirrhosis and chronic hepatitis B,serum IL-17 levels increased in those with higher serum ALT levels（t=24.5,P<0.05;t=22.4,P<0.05）and with higher serum bilirubin levels（t=7.3,P<0.05;t=12.8,P<0.05）;the frequency of IL-17-197 AA,AG and GG distribution in patients with liver cirrhosis were 75.0%,10.0% and 15.0%,and allele A distribution frequency was 57.5%,G distribution frequency was 42.5%,while in patients with chronic hepatitis B were 25.8%,16.7%,57.5% and 34.2%,65.8%,respectively,significantly different between the two groups （P<0.05）;the priority frequencies in patients with liver cirrhosis were IL-17-197 AA genotype and A allele,the priority frequencies in patients with chronic hepatitis B were GG genotype and G allele,the priority frequencies in asymptomatic HBV carrier were AA genotype and A allele,and the priority frequencies in self-limited individuals were GG genotype and G allele. Conclusion The host immunity and genetic background determine the outcomes of HBV infection and serum IL-17 plays an important role in the process of chronic hepatitis B virus infection. The AA genotypes and A alleles of IL-17-197A/G might be the HBV susceptible host genes,which increase the adverse outcome of HBV infection.

Key words: Liver cirrhosis, Hepatitis B, Interleukin -17, Gene polymorphism