Associations between interleukin-1 polymorphisms and susceptibility to vasculitis: a meta-analysis

The objective of this study was to determine whether interleukin-1 (IL-1) polymorphisms are associated with susceptibility to vasculitis. A meta-analysis was conducted to investigate possible associations between IL-1A, IL-1B, and IL-1 receptor antagonist (IL1RN) polymorphisms and vasculitis. A total of 17 studies involving 1384 vasculitis cases [Beh double dagger et's disease (BD), IgA vasculitis, anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), Kawasaki disease (KD), giant cell arteritis, and Takayasu's arteritis] and 2710 controls were included in the meta-analysis. This analysis showed an association between BD and the TT + TC genotypes of the IL-1A-889 C/T polymorphism in the entire study population [odds ratio (OR) = 0.623, 95 % CI = 0.395-0.981, p = 0.045), and a trend toward an association in a Turkish population (OR = 0.578, 95 % CI = 0.331-1.010, p = 0.054). A meta-analysis of the IL1RN polymorphism revealed no association with vasculitis in all study subjects (OR for IL1RN*2 = 0.904, 95 % CI = 0.626-1.304, p = 0.588). However, stratification by ethnicity revealed a significant association between the IL1RN*2 allele and vasculitis including AAV, BD, KD in Asians (OR = 2.393, 95 % CI = 1.429-4.006, p = 0.001), but not in Caucasian and Turkish populations (OR = 0.776, 95 % CI = 0.487-1.238, p = 0.288; OR = 0.914, 95 % CI = 0.667-1.252, p = 0.576, respectively). No association was found between vasculitis and the IL-1B-511 C/T polymorphism, or the IL-1B+3953 C/T polymorphism. This meta-analysis suggests that the IL-1A-889 C/T polymorphism is associated with susceptibility to BD, and that the IL1RN*2 allele is associated with susceptibility to vasculitis including AAV, BD, and KD in Asians.