Evaluation of single nucleotide polymorphism in interleukin 22 (IL-22) gene and its association with chronic hepatitis B infection.

Abstract

This study aimed to evaluate rs1179251 single nucleotide polymorphism in the IL-22 gene as a host factor and its effect on chronic hepatitis B infection. Interleukin 22 (IL-22) belongs to a group of recently discovered cytokines, and it is produced and secreted by innate lymphoid cells (ILCs) and T helper 22 (Th22) cells. This cytokine plays dual roles as pro-inflammatory and anti-inflammatory effects in various conditions and different tissues of the body. This study was performed based on a case-control format to assess IL-22 rs1179251 single nucleotide polymorphism genotypic and allelic frequencies among 227 hepatitis B chronic patients and 227 healthy controls. The polymerase chain reaction and restriction fragment length polymorphism techniques were employed to determine the polymorphism's genotypes. Genotypes Frequencies in patients' group were determined CC 59.91%, CG 37.89%, and GG 2.20% respectively in comparison to CC 63.44%, CG 31.72% and GG 4.85% in control group. The findings revealed that there was no statistically significant difference in the genotypes (P=0.156) frequencies of IL-22 gene polymorphism (rs1179251) between patients and control groups. No association was found between rs1179251 single nucleotide polymorphism in IL-22 gene and chronic hepatitis B infection. So, in spite of the importance of IL-22 gene in immune responses, the studied polymorphism does not serve a decisive role in susceptibility to hepatitis B virus chronic infection.