Interleukin-28B genetic variations and spontaneous clearance of hepatitis C antibody-positive blood donors in China.

BACKGROUND: Single-nucleotide polymorphisms (SNPs) near the interleukin (IL)28B gene have been shown to be associated with spontaneous clearance of hepatitis C virus (HCV) infection in western populations. Anti-HCV-reactive and HCV RNA-negative samples were often found in Chinese blood donors. This study was to determine whether the IL28B gene variant is also associated with the natural outcome of HCV infection in Chinese blood donors.

STUDY DESIGN AND METHODS: A total of 111 anti-HCV-negative blood donors and 100 anti-HCV-reactive subjects were enrolled in this study. HCV-infected blood donors were classified into spontaneous clearance group and chronic infection group through HCV RNA detection. IL28B genetic variations (rs8099917 and rs12979860) were genotyped by polymerase chain reaction and direct sequencing.

RESULTS: A total of 24 (24.0%) donors spontaneously cleared HCV. The rs12979860 C allele frequency was 90.3% and the rs8099917 T allele frequency was 96.7% in our study. The rs12979860 CC genotype was strongly associated with spontaneous HCV clearance. Female blood donors had a higher rate of spontaneous HCV clearance than male donors (15/42 [35.7%] vs. 9/58 [15.5%], p = 0.02).

CONCLUSIONS: The rs12979860 CC variant upstream of IL28B gene is associated with spontaneous clearance of HCV in Chinese blood donors and female donors are more likely to clear HCV infection than male donors.