Genetic Polymorphisms of the IFNLR1 Gene Correlate with HCV Infection and Biochemical Features of Chronic HCV Patients in Yunnan, China.

Hepatitis C virus (HCV) infection could lead to serious liver diseases, but the pathogenic mechanisms were not completely clear. Cytokines play critical roles in infection, and the genetic polymorphisms in the cytokine genes are widely studied in infectious diseases. The variations in the IL28B gene were associated with HCV infection, viral clearance, and biochemical features of patients, but the studies of its receptor (IFNLR1/IL10RB) were rare. In this study, we collected 395 chronic HCV patients and 397 normal controls to investigate the genetic role of the IFNLR1 gene. Eight tagSNPs were genotyped, and the haplotypes were constructed. Genotypes CT (23.80% vs. 17.13%) and TT (75.19% vs. 81.36%) of rs7532146 showed higher and lower frequencies in HCV patients than that in controls (P = .022; P = .039). Haplotypes GGAATCTC (P = .028) and AAAGCCCT (P = .002) were risk factors for HCV infection, but haplotype GAAATCTT (P = .027) played protective role in HCV infection. Moreover, we identified that the ALT level was significantly lower in HCV patients with genotype TT of rs4489498 than those with other genotypes (CC vs. TT: P = .037; CT vs. TT: P = .013). HCV viral load was highest in HCV patients with genotype CC of rs4489498 than in patients with other two genotypes (CC vs. CT: P = .006; CC vs. TT: P = .039). In conclusion, the genotypes and haplotypes in the IFNLR1 gene were associated with HCV infection and biochemical features of Chinese HCV patients.