Abstract: Objective To investigate blood IFN-γ gene polymorphism in patients with hepatitis B-induced acute-on-chronic liver failure （ACLF）. Method Single nucleotide polymorphism （SNP） technique was applied to detect blood single nucleotide polymorphism of IFN-γ gene +874T/A and +2109 A/G in 51 patients with ACLF and 50 healthy controls. Results The frequency of +874 locus TA+AA genotype in patients with ACLF was 54.9%,much higher than 24.0% in the control（P<0.05）,and A allel was 38.2%,also much higher than 22.0% in the control（P<0.05）;the frequency of +2109 locus AG+GG genotype in patients with ACLF was 51.0%,much higher than 26.0% in the control（P<0.05）,and G allel was 32.4%,much higher than 16.0% in the control（P<0.05）;there was no significant difference as respect to the frequencies of +874 and +2109 allele and genotype between 28 survivals and 23 dead（P>0.05） at the end of 3 month follow-up. Conclusion IFN-γ gene +874 locus A allel and its genotype and +2109 locus G allel and its genotype might be the genetic susceptibility genes for the occurrence of ACLF.

Key words: Acute-on-chronic liver failure, Hepatitis B, IFN-γ, Gene polymorphism