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 hepatic diseases worldwide. Along with viral and immunological components, host genetic background including single 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 impairs the T cell response in chronic viral infections. In this research the relationship between a single nucleotide polymorphism of exon 5 of the programmed cell death 1 gene (PD1) and susceptibility to chronic hepatitis B infection in an Iranian population has been studied.   Materials and Methods: In such case-control study, genomic DNA from 160 chronic HBV patients and 150 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 7785 of the exon 5 of PD1 gene were %12.5, %40 and %47.5 in patient group and %10.7, %42.7 and %46.6 in control 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 some immunological disorders such as rheumatoid arthritis was observed, results of this study suggest that there is no association between PD1 exon 5 C/T single nucleotide polymorphism and susceptibility to chronic hepatitis B in the Iranian population