Association between IL-33 Gene Polymorphisms (rs1929992, rs7044343) and Systemic Lupus Erythematosus in a Chinese Han Population.

OBJECTIVE: Interleukin-33 (IL-33) is a member of the IL-1 family, and previous studies found the single-nucleotide polymorphisms (SNPs) in the IL-33 gene was related to susceptibility to autoimmune diseases, including rheumatoid arthritis, ankylosing spondylitis and Behcet's disease. To date, no study has discussed the potential association between IL-33 gene polymorphisms and systemic lupus erythematosus (SLE).

METHODS: We conducted a case-control study including 371 SLE patients and 408 healthy controls to investigate the correlation between the SNPs of IL-33 gene (rs1929992, rs7044343) and SLE in a Chinese Han population.

RESULTS: There was significantly lower expression of allele G for rs1929992 in SLE patients than that in controls (G versus A, P = 0.012, OR = 1.310, 95% CI: 1.060-1.624 after adjustment with sex). Similarly, genotype GG was associated with the susceptibility to SLE as compared with the AA genotype (P = 0.017, OR = 1.714, 95% CI: 1.101-2.669 after adjustment with sex). We also found statistical significance in the dominant model (GG+GA versus AA, P = 0.017, OR = 1.481, 95% CI: 1.074-2.044 after adjustment with sex). However, we found no strong evidence for the association of IL-33 rs7044343 polymorphism with SLE. Moreover, association studies were performed on the relationship between the IL-33 gene polymorphisms and lupus nephritis as well as nine clinical features of SLE, but there was no significant association regarding the distribution of allele and genotype frequencies between SLE patients positive and negative for the presence of sub-phenotypes.

CONCLUSION: Our findings indicate that IL-33 rs1929992 polymorphism may be a potential biomarker for susceptibility to SLE.