Association of Toll-Like Receptor-9 Polymorphism with Host Susceptibility to Chronic Hepatitis B Virus Infection Among Iraqi Patients

Abstract

TLR9 is essential for the innate immune response by detecting intracellular viral dsDNA, which activates the immune response against HBV. In this research, we aimed to see whether the TLR9 rs187084, rs352140, and rs5743842 polymorphisms were associated with HBV persistence in Iraqi chronic HBV patients. These SNPs were genotyped by the RFLP-PCR technique in 100 HBV patients and 120 healthy controls. The frequencies of the rs187084 G allele were highly significant in HBV patients compared to controls (133 vs. 84 %; p 4.681e-11). with an OR of 3.687. (95% CI: 2.482-5.476) The GG genotype was significantly more prevalent in patients than in controls. (55 vs 10%; p 0.0001), with an OR of 10.00 (95% confidence interval: 4.48-22.32). Also, the frequency of the rs352140 C allele was higher in HBV patients than control (104 vs. 72 %; p= 2.72e-6), with an OR of 2.527 (95% CI: 1.709-3.74). The frequency of rs352140 SNP CC genotypes in patients was also significantly increased. (38 vs 8.3%; p= 0.0001) with an OR of 6.741 (95% CI: 3.14-14.45). Haplotype analysis revealed that the A-T haplotype of TLR-9 SNPs (rs187084 and rs352140) was associated with a considerably lower HBV risk. The other haplotypes of TLR-9 SNPs (rs187084 and rs352140) didn't show any significant. In conclusion, these SNPs are associated with the susceptible persistence of HBV infection, and this is the first study to look for an association between polymorphisms in genes implicated in the innate immune response and HBV infection in the Iraqi population.