Association of cytokine gene polymorphisms (IL‑6, IL‑12B, IL‑18) with Behcet's disease : A meta-analysis.

PURPOSE: This study aims to investigate the association of cytokine gene polymorphisms with the risk of Behcet's disease (BD) via comprehensive meta-analysis. METHODS: The Embase and PubMed databases covering the period from the earliest possible year to May 2015 were searched. A total of 13 eligible articles including 2,065 BD patients and 1,559 controls were recruited. Odds ratios (ORs) and 95 % confidence intervals (CIs) were used to assess the strength of the associations. Potential publication bias was evaluated using Egger's linear regression test. RESULTS: Meta-analysis indicated associations between IL‑6 rs1800795, IL‑12B rs3212227, and IL‑18 rs1946518 in all study subjects: IL‑18 rs1946518 in the dominant model (IL‑18 rs1946518: OR = 0.48, 95 % CI: 0.34-0.70, P = 0.000) and the homozygote model (IL‑18 rs1946518: OR = 0.40, 95 % CI: 0.25-0.65, P = 0.000); and IL‑6 rs1800795 and IL‑12B rs3212227 in the dominant model (IL‑6 rs1800795: OR = 0.53, 95 % CI: 0.39-0.72, P = 0.000; IL‑12B rs3212227: OR = 1.26, 95 % CI: 1.06-1.48, P = 0.007; IL‑18 rs1946518: OR = 0.46, 95 % CI: 0.33-0.65, P = 0.000). No significant evidence for associations of IL‑18 rs187238 polymorphisms with BD susceptibility was detected. CONCLUSION: In summary, this meta-analysis finds that IL‑6 rs1800795 and IL‑18 rs1946518 polymorphisms decrease the risk of BD. However, IL‑12B rs3212227 increases BD susceptibility. Further large-scale investigation of this association is necessary.