Association Between Interleukin-33 Polymorphism and Henoch-Schönlein Purpura in Chinese Children

Interleukin-33 (IL-33) was one of the members of IL-1 family, and it was reported that the single nucleotide polymorphisms (SNPs) in the IL-33 gene was contribute to the susceptibility to immune related diseases, including rheumatoid arthritis, asthma, Behcet’s disease, systemic lupus erythematosus and ankylosing spondylitis. However, the potential association between SNPs in IL-33 gene and Henoch-Schönlein purpura (HSP) was not explored. We designed a case-control study, a total of 181 HSP patients and 202 healthy pediatric controls were included, which aimed to study the relationship between the SNPs in the IL-33 gene (rs1929992, rs7044343) and HSP with a Chinese pediatric cohort. There were no evidence for the association of rs1929992 and rs7044343 polymorphism in IL-33 gene with pediatric HSP patients (C versus T, P = 0.622, OR = 0.931, 95% CI: 0.7 - 1.238; TT versus CC, P = 0.742, OR = 0.908, 95% CI: 0.513 - 1.609; CT versus CC, P = 0.158, OR = 0.714, 95% CI: 0.446 - 1.141 and C versus T, P = 0.920, OR = 0.986, 95% CI: 0.742 - 1.309; TT versus CC, P = 0.939, OR = 0.978, 95% CI: 0.549 - 1.741; CT versus CC, P = 0.416, OR = 0.817, 95% CI: 0.501 - 1.331, respectively). Moreover, association studies were performed on the correlation between IL-33 gene polymorphisms and HSP nephritis patients as well as patients with gastrointestinal manifestation and joint involvement. However, there were no significant association regarding the distribution of allele and genotype frequencies between HSP patients with different system involvement and healthy controls either. The present findings indicated that both of rs1929992 and rs7044343 in gene IL-33 polymorphism were not related to the susceptibility to HSP and the different system involvement of HSP patients.