Association between IL and 6 gene polymorphisms and circulating IL-6 levels in Behcet’s disease: A meta-analysis

Abstract

ObjectivesThis study aimed to investigate the association between circulating interleukin-6 (IL-6) levels and Behçet’s disease (BD), and associations between polymorphisms in IL-6 gene and BD susceptibility. MethodA search of relevant articles was conducted in the Medline, Embase, and Web of Sciences databases. Subsequently, a meta-analysis was performed to assess circulating IL-6 levels in both the BD and control groups. Additionally, we investigated the association between the functional IL-6 promoter −174 G/C polymorphism and the risk of developing BD. ResultsNineteen studies involving 923 patients with BD and 910 controls were included in this meta-analysis. The results demonstrated a significant elevation in circulating IL-6 levels in the BD group than in the control group (standardized mean difference [SMD] = 1.600, 95 % confidence interval [CI] = 0.732–2.496, P<0.001). Furthermore, IL-6 levels were significantly higher in the active disease group than in the inactive disease group (SMD=1.292, 95 % CI=0.059–2.525, P<0.001). Intriguingly, the meta-analysis revealed an association between BD and the IL-6 CC+CG genotype in Arabs (odds ratio [OR] = 0.588, 95 % CI=0.393–0.881, P=0.010), whereas no such association was observed in European or Asian populations. ConclusionsOur meta-analysis revealed significantly higher circulating IL-6 levels in patients with BD and found evidence of association between IL and 6 promoter −174 G/C and BD susceptibility.