Polymorphisms of Inflammatory Cytokine Genes and Risk for Intracranial Aneurysm: A Systematic Review and Meta-Analysis

PURPOSE: Inflammatory cytokines are thought to be involved in the pathogenesis of intracranial aneurysm (IA), although results among studies in the literature are inconsistent. This article sought to review studies on the associations among polymorphisms in inflammatory cytokine genes and IA risk and to provide recommendations for future research. MATERIALS AND METHODS: A systematic search of PubMed, Embase, and Web of Science was conducted up to August 4, 2019. The associations between polymorphisms of inflammatory cytokine genes and IA risk were estimated by pooled odds ratios (ORs) and 95% confidence intervals (CIs). Subgroup analyses were performed according to race. Qualitative systematic review was conducted for variants that were studied in only one study. All analyses were performed using STATA 12.0. RESULTS: 13 studies investigating the associations between polymorphisms in five inflammatory cytokine genes (TNF-α, IL-1α, IL-1β, IL6, and IL-12B) and IA were reviewed. Combined results showed that the A allele of TNF-α rs1800629 polymorphism has a protective effect against IA (dominant model: OR=0.65, 95% CI=0.47–0.89, p=0.007). No associations were identified between polymorphisms in IL-1α rs1800587, IL-1β rs16944, IL6 rs1800795 and rs1800796, or IL-12B rs3212227 and IA risk. CONCLUSION: This review demonstrated an association between TNF-α rs1800629 polymorphism and IA in Caucasians, illustrating the potentially important role of genes involved in inflammation in IA.