Association between interleukin-20 gene Rs 1518108 polymorphisms of and the risk of chronic hepatitis B

The outcome of Hepatitis B virus (HBV) infection is variable in different individuals. Liver injuries in chronic HBV infection appear to be mostly due to the host’s immune response to control the infection. Various studies have provided evidence for an association between single nucleotide polymorphisms (SNPs) within interleukin genes and susceptibility to infectious diseases. The aim of this study was to examine IL-20 gene SNP (rs1518108) in regard to genotype and allele frequencies and its association with HBV outcome. The SNP at position rs1518108 of IL-20 gene was analyzed in the patients with chronic HBV infection and healthy volunteers as control group. Blood samples were collected from 134 ELISA positive hepatitis B patients as well as 119 healthy controls. Evaluation of SNP was performed to find differences in allele and genotype frequencies by PCR-RFLP method in this case-control study. Results showed a slightly higher CT genotype among the patients but the difference was not statistically significant (P=0.856). Genotype and allele frequencies were found in both groups and no significant difference was observed in the frequency of interleukin-20 gene polymorphism (rs1518108) between chronic HBV patients and healthy subjects in relation to genotype (P=0.827) and allele (P=0.784) frequencies. The results suggested that there is no correlation between interleukin-20 (rs1518108) polymorphism with HBV infection or disease progression. Polymorphism could not be regarded as a host genetic factor associated with the HBV infection outcome. Genetic factors other than interleukin-20 or other polymorphisms of this gene, seem to be involved in the process of viral clearance and prevention of chronic hepatitis B.