OBJECTIVETo investigate the association of single nucleotide polymorphisms (SNPs) in the interleukin 17 (IL-17) gene and serum protein levels in patients with chronic hepatitis C virus (HCV) infection.

METHODSA total of 228 patients with chronic HCV infection and 81 healthy controls were enrolled in the study. The frequencies of IL-17 rs8193036 and rs2275913 polymorphisms were detected by the TaqMan SNP genotyping assay. Serum levels of IL-17 protein were detected by ELISA. Pairwise comparisons were made by the Chi-square test, and the significance of between-group differences was assessed by the Student's t-test with P less than 0.05.

RESULTSThe patients with chronic HCV infection and the healthy controls showed similar frequencies of the rs8193036 C/T allele (x2 = 1.428, P = 0.232) and the rs2275913 A/G allele (x2 = 0.106, P = 0.744). In addition, the two groups showed similar distribution of the rs8193036 CC (chronic HCV infection: 46.49% vs. healthy controls: 41.98%), CT (45.61% vs. 44.44%) and TT (7.89% vs. 13.58%) genotypes (x2 = 2.346, P = 0.309), and of the rs2275913 AA (16.23% vs. 13.58%), AG (48.25% vs. 50.62%) and GG (35.53% vs. 35.80%) genotypes (x2 = 0.340, P = 0.844). Subgroup analysis of chronic HCV infection patients stratified according to HCV genotypes 1 and 2 showed no differences in the distribution of rs8193036 and rs2275913 alleles (x2 = 1.127, P = 0.288; x2 = 1.088, P = 0.297) and genotypes (x2 = 2.825, P = 0.246; x2 = 0.970, P = 0.616). However, the chronic HCV infection group did show significantly higher levels of serum IL-17 than the controls (97.67+/-39.68 vs. 71.60+/-19.78 pg/ml, t = 2.414, P = 0.033).

CONCLUSIONChronic HCV infection is associated with increased serum IL-17; however, the IL-17 polymorphisms rs8193036 and rs2275913 were not associated with chronic HCV infection susceptibility in this study's Chinese cohort.