Interactions of interleukin-12A and interleukin-12B polymorphisms on the risk of intracranial aneurysm

Several lines of evidence indicate that inflammatory processes play pivotal role in the development of intracranial aneurysm (IA). Recently, polymorphisms in the interleukin-12 (IL-12) gene were shown to be associated with immune-mediated inflammatory disease. The aim of this study was to investigate the interactions of IL-12A and IL-12B polymorphisms on the risk of IA in a Chinese population. A total of 422 individuals (including 164 patients with IA and 258 controls) were involved in the study. The polymorphisms (i.e., rs2243115 and rs568408 in IL-12A and rs3212227 in IL-12B) were genotyped by polymerase chain reaction-restriction fragment length polymorphism assay and DNA sequencing. We found an association of the AC/CC genotypes and C allele of IL-12B rs3212227 with an increased risk of IA, compared with the AA genotype and A allele (AC/CC vs. AA: OR = 2.09, 95 % CI: 1.29-3.38; C vs. A: OR = 1.45, 95 % CI: 1.10-1.91). Moreover, a significant gene interaction of IL-12A and IL-12B was evident on the risk of IA, and subjects carrying variant genotypes of IL-12B rs3212227 had an increased risk of IA. In the stratified analysis by gender, the IL-12B rs3212227 AC/CC genotypes had an increased risk of IA compared with the AA genotype in male patients (AC/CC vs. AA: OR = 4.63, 95 % CI: 1.92-11.16). These findings suggest that the IL-12A and IL-12B independently and jointly be involved in the susceptibility to IA.