Interleukin-16 gene polymorphisms are considerable host genetic factors for patients' susceptibility to chronic hepatitis B infection.

Host genetic background is known as an important factor in patients' susceptibility to infectious diseases such as viral hepatitis. The aim of this study was to determine the effect of genetic polymorphisms of interleukin-16 (IL-16) cytokine on susceptibility of hepatitis B virus (HBV) infected patients to develop chronic HBV infection. Genotyping was conducted using PCR followed by enzymatic digestion and RFLP (restriction fragment length polymorphism) analysis. We genotyped three single nucleotide polymorphisms (SNPs) in the Il-16 gene (rs11556218 T>G, rs4778889 T>C, and rs4072111 C>T) to test for relationship between variation at these loci and patients' susceptibility to chronic HBV infection. Allele frequency of Il-16 gene rs4072111 and rs11556218 was significantly different between chronic HBV patients and healthy blood donors. Genotype frequency of rs4778889 polymorphism of Il-16 gene was significantly different when chronic HBV patients and HBV clearance subjects were compared. Our results showed that Il-16 gene polymorphisms are considerable host genetic factors when we chase biomarkers for prognosis of HBV infected patients.