Previous studies suggested that interleukin-17 and Th17 cell play an important role in the pathogenesis of childhood Henoch-Schonlein purpura (HSP). The purpose of our study is to elucidate whether the IL17A and IL17F gene polymorphisms are susceptibility genes for the development of HSP in Chinese children. A total of 148 HSP patients and 202 controls were enrolled for analyzing the single nucleotide polymorphisms (SNP) of IL17A (rs2275913, rs8193037 and rs3819025) and IL17F (rs763780 and rs9463772). TaqMan Real-Time polymerase chain reaction method was used in SNP genotyping. Compared to the healthy controls, the IL17A rs2275913 variant allele A showed a significant association with HSP [odds ratio (OR) 0.70; 95 % CI 0.51-0.94, P = 0.018]. Genotyping analysis demonstrated rs2275913 was associated with a decreased HSP risk (G/A vs. G/G: OR 0.56; 95 % CI 0.33-0.95; A/A vs. G/G: OR 0.46; 95 % CI 0.24-0.86; P = 0.032). Also, our findings showed that the A allele of IL17A rs3819025 was associated with a higher risk of HSP nephritis (OR 1.61; 95 % CI 1.00-2.58; P = 0.047). In addition, a risk haplotype of IL17A (GGA) was found (OR 1.84; 95 % CI 1.17-2.88; P = 0.008). However, no significant differences between HSP patients and healthy controls were observed when comparing genotype, allele or haplotype frequencies of the IL17F rs763780 and rs9463772 polymorphisms. In this study, we confirmed that the rs2275913 polymorphism of the IL17A gene was associated with susceptibility to HSP in Chinese children. However, there was no relationship between IL17F rs763780 and rs9463772 polymorphisms and HSP susceptibility.
Keywords: Henoch–Schonlein purpura; Inflammation; Interleukin-17; Polymorphism.