TNF Polymorphisms in Patients with Behçet Disease: A Meta-analysis

Background and Aims Polymorphisms in the tumor necrosis factor (TNF) gene at the locations −308, −238, −863, −857 and −1031 have been studied in various ethnic groups for possible association with Behçet's disease. The aim of this meta-analysis is to examine the association between polymorphism in the TNF gene at the locations −308, −238, −863, −857 and −1031 and Behçet's disease. Methods A literature review was performed using MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials for original studies published in English up to October 31, 2009 and that examined the association of the TNF-α promoter polymorphisms with Behçet's disease. All pooled odds ratios (OR) were derived from random-effects model with its 95% confidence intervals (CI). We assessed statistical heterogeneity among studies using Cochrane Q test and by calculating I2 . The Cochrane collaboration's software program, RevMan 5 was used to prepare and complete this review. Results The literature search resulted in 13 studies. Ten studies met the included criteria and thus were selected. Overall, −1031C (OR = 1.35, 95% CI = 1.09–1.68), −238A (OR = 1.51, 95% CI = 1.12–2.04) and −857T (OR = 0.76, 95% CI = 0.58–0.98) had a significant association with Behcet's disease. The pooled estimates for the other polymorphisms were not statistically significantly associated with Behcet's disease; −308A and −863A. Conclusions Behcet's disease was associated with the −1031C, −238A and the −857T promoter polymorphisms in various ethnic groups.