Association Of IL28B Gene Polymorphisms With Spontaneously Cleared Of HCV Infection And Treatment Response

Objective:To investigate the relationship between the single nucleotide polymorphisms (SNPs) in IL28B and spontaneous clearance with HCV infection and treatment response by interferon (IFN) and ribavirin (RBV) combination.Methods:192outpatients with chronic hepatitis C infection in2009-2011were divided into three groups, including84cases with complete treatment by interferon and ribavirin and24weeks follow-up(65cases with sustained virologic response (SVR)and19cases with non-response),72untreated cases and36cases with spontaneous virologic clearance. We extracted the DNA from blood samples and performed SNPs of IL28analysis by MALDI-TOF mass spectrum (MALDI-TOF MS) geneotyping at positions rs12979860,rs8099917, rs12980275and rs7248668,comparing the significant differences of allele and genotype among the three groups by statistical analysis.Results:1. The genotype frequencies of SNPs in four sites of IL28B in China were as follows:the rs12979860site was detected86.5%of C/C and13.5%of C/T genotype and TT genotype undetected, both of the rs8099917and rs12980275sites were detected87.5%of T/T and12.5%of G/T genotype,86.5%of A/A and13.5%of G/A genotype,respectively and G/G genotype not found,while the rs7248668site without A/A genotype were detected and87.5%of G/G and12.5%of G/A genotype were.detected. The analysis of linkage disequilibrium in four sites found that rs12979860is in complete linkage disequilibrium with other sites(D’=1,r2=0.87-1).2.The genotype frequencies of C/C(95.5) in rs12979860site and A/A(95.4%) in rs12980275site with chronic HCV infection in group of sustained virologic response were higher than that in non-response group(x2=8.03,p=0.004). Likewise, the genotype frequencies of T/T(95.4%) in rs8099917site and G/G(95.4%) in rs7248668site in sustained virologic response group were higher compared with non-response group with chronic HCV infection(χ2=5.20, P=0.02).3.The genotype frequencies of C/C(94.4%) in rs12979860site and A/A(94.4%) in rs12980275site in spontaneous clearance group were significantly higher than in untreated group with chronic HCV infection (χ2=4.80,P=0.03), while the genotype frequencies of T/T in rs8099917site and G/G in rs7248668site (94.4%) similarly significantly increased in spontaneous clearance group compared with untreated group with chronic HCV infection(x2=4.22,P=0.04).4.There was no significant differences of genotype frequencies of C/C in rs12979860site (95.4%) in sustained virologic response group with chronic HCV infection compared with HCV spontaneous clearance group(x2=0.04, P=0.84).Conclusion:1.The polymorphism of four sits (rs12979860, rs8099917, rs12980275,rs7248668)in IL28B with chronic HCV infection in China mainly are C/C,T/T,A/A and G/G,respectively.2.The polymorphism of rs12979860,rs8099917, rs12980275and rs7248668in IL28B is correlated with spontaneous virologic clearance and SVR after combined treatment by interferon (IFN) and ribavirin (RBV) in patients with chronic HCV infection.