Background and purpose: Cytokines are a group of endogenous proteins which play an influential role in regulating the inflammatory responses and defeating infectious diseases. Elevated levels of proinflammatory cytokines and their receptors are usually observed in association with immune responses against viral infections such as hepatitis B virus (HBV) infection. IL 12 and its receptor play an important role in the clearance of viral infections, especially HBV. The aim of this study was to investigate the association between interleukin 12 receptor B1 gene single nucleotide polymorphism (rs3746190 A/G) and chronic HBV infection susceptibility.

Materials and methods: In a case control study, genomic DNA of 150 chronic HBV infected patients and 150 healthy controls was extracted by salting out method and single nucleotide polymorphism (rs3746190 A/G) was genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

Results: A total of 300 individuals were studied. The frequency of rs3746190 A/G gene for CC, CT, TT genotypes was 40.7%, 46%, and 13.3% in chronic patients and 38%, 49.3%, and 12.7% in control group, respectively. After genotyping and statistical analysis, no significant difference was seen between the cases and controls (P=0.845).

Conclusion: This study did not find any significant association between rs3746190 A/G single nucleotide polymorphism of the IL12RB1 gene and susceptibility to chronic hepatitis B virus infection. Therefore, polymorphism in gene IL12RB1 is not an effective factor for susceptibility to chronic HBV.