Lack of the association beetween single nucleotide polymorphism in programmed cell death 1 gene and susceptibility to chronic hepatitis B infection in the Iranian population

Introduction: Hepatitis B virus (HBV) is one of the most important causative agents of chronic hepaticdiseases worldwide. Along with viral and immunological components, host genetic background includingsingle nucleotide polymorphisms (SNPs) has a critical role on chronicity or clearance of infection.Programmed cell death 1 is an inhibitory receptor which is expressed on virus-specific T cells and impairsthe T cell response in chronic viral infections. In this research the relationship between a single nucleotidepolymorphism of exon 5 of the programmed cell death 1 gene (PD1) and susceptibility to chronic hepatitisB infection in an Iranian population has been studied.Materials and Methods: In such case-control study, genomic DNA from 160 chronic HBV patients and150 healthy controls was extracted and genotyping was performed by PCR-RFLP method.Results: Frequencies of TT, CT and CC genotypes of single nucleotide polymorphism on position 7785of the exon 5 of PD1 gene were %12.5, %40 and %47.5 in patient group and %10.7, %42.7 and %46.6 incontrol group, respectively. No statistically significant difference was seen between case and control groups(p value: 0.832).Conclusion: Although in later studies the relationship between this SNP and susceptibility to someimmunological disorders such as rheumatoid arthritis was observed, results of this study suggest that thereis no association between PD1 exon 5 C/T single nucleotide polymorphism and susceptibility to chronichepatitis B in the Iranian population.