Abstract Hepatitis B virus (HBV) is a major health problem worldwide. HBV infection can lead to major liver complications such as liver cirrhosis and hepatocellular carcinoma (HCC). Cytokines are small proteins that have important roles in cell signaling and regulation of immune system responses. A recently discovered cytokine, Interleukin-34 (IL-34), promotes differentiation, proliferation and survival of mononuclear cells. New studies reveal that IL-34 has an antiviral activity in vivo and in vitro. The aim of this study is to investigate the association between a single nucleotide polymorphism (SNP) in IL-34 gene (rs34881169 G/A) and chronic HBV infection.

Methods In this case control study genomic DNA of 114 chronically patients and 101 healthy controls was extracted by salting out methods. Genotype of rs34881169 SNP was determined by polymerase chain reaction-restriction fragment length poly morphism methods.

Result A total of 215 individuals (mean age: 40.26±13.40, range from 11 to 80 years) have been studied. No statistically significant difference be¬tween case and control groups has been observed (P=0.281). Distribution of genotypes for rs34881169 were 32 GG (28.1%), 49 GA (43.0%), 33 AA (28.9%) in chron¬ic HBV patients and 19 GG (18.8%), 49 GA (48.5%), 33 AA (32.7%) in control group.

Discussion In the present study, no signifi¬cant relation between rs34881169 SNP of the IL-34 gene and susceptibil¬ity to chronic hepatitis B virus infection was found. Therefore, this polymorphism in gene IL-34 is not a prognostic factor for susceptibility to chronic HBV infection.