Association Between The Polymorphism Of Type I Interferon Receptor Promoter Gene And Treatment Response To Antivirus In Patients With Chronic Hepatitis C

Objective:To investigate the association between polymorphism of type1interferon receptor(IFNAR1) promoter gene and the treatment response to interferon alpha (IFN a) in patients with chronic hepatitis C(CHC).Methods:73CHC patients who consented to receive peg-IFN α,in combination with ribavirin therapy were enrolled in this study. The treatment response were monitored. The subjects were divided into two groups response and no response.The genes of IFNAR1promoter in these patients were sequenced. Measurement data were analyzed by t test and enumeration data were analyzed by Chi square test.Results:1.Among the seventy-three patients treated with peg-IFN a and ribavirin,47patients achieved response and26patients had no response. There were no significant difference in sex, age, alanine aminotransferase (ALT) tsesting and HCV RNA genetype testing before treatment between the responsers and the non responsers, but the HCV RNA level testing before treatment was significant lower in the responsers than the non responsers,P=0.003.2.Polymorphisms were identified in IFNAR1promoter gene, which include G/C substitution at locus-568, C/T substitution at locus-408, C/T substitution at locus-3and GT microsatellite repeat sequence at locus-77.These four sites were in linkage, and they composed ten haplotypes, such as haplotype-568C/-408C/-77(GT)5/-3C and haplotype-568C/-408T/-77(GT)5/-3T (appearace rate:52.054%and15.068%).3.The relation between the genetype of IFNAR1and the response rate to antivirus therapy:The response rate to antivirus therapy in CHC patients with haplotype non-568C/-408C/-77(GT)5/-3C was higher than that in patients with haplotype-568C/-408C/-77(GT)5/-3C (77.1%vs52.6%,x2=4.773, P=0.029). The response rate to antivirus therapy in CHC patients with haplotype-568C/-408T/-77(GT)5/-3T was higher than that in patients with haplotype non-568C/-408T/-77(GT)5/-3T (90.9%vs59.7%,x2=3.92, P=0.048). Conclusion:The genetype-568C/-408T/-77(GT)5/-3T or non-568C/-408C/-77(GT)5/-3C of the IFNAR1prometer is associated with better response to IFN-α treatment in patients with chronic hepatitis C, suggesting that Polymorphisms of IFNAR1promoter gene are associated with the treatment response to IFN-a in CHC patients.