Association Of Six Well-Characterized Polymorphisms In Tnf-Alpha And Tnf-Beta Genes With Sarcoidosis: A Meta-Analysis

Backgrounds: In this study, we aimed to investigate the association of six well-characterized polymorphisms in tumor necrosis factor alpha and beta (TNF-alpha and TNF-beta) genes with the risk for sarcoidosis via a comprehensive meta-alpha nalysis.Methods And Findings: The electronic MEDLINE (Ovid) and PubMed databases covering the period from the earliest possible year to June 2013 were searched. Total 13 qualified articles including 1584 patients with sarcoidosis and 2636 controls were recruited. The data were analyzed by RevMan software, and risk estimates were expressed as odds ratios (ORs) and 95% confidence intervals (95% CIs). Analyses of the full data set failed to identify any significant association of TNF-alpha gene -307A (OR=1.25; 95% CI: 0.98-1.59), -1031C (OR=0.88; 95% CI: 0.71-1.1), -863A (OR=0.89; 95% CI: 0.72-1.11), -238A (OR=0.97; 95% CI: 0.71-1.32), and -857T (OR=1.14; 95% CI: 0.74-1.77) alleles, but a significant association for TNF-beta 252A allele (OR=1.65; 95% CI = 1.33-2.04; P<0.00001). Under a random-effects allelic model, there was marginally significant increased risk of sarcoidosis for -307A allele among Caucasians (OR=1.25; 95% CI: 0.96-1.62; P=0.09) but not among Asians (OR=2.12; 95% CI: 0.31-14.27; P=0.44). There was a low probability of publication bias as reflected by the fail-safe number.Conclusions: This meta-alpha nalysis extended previous findings on the association between the TNF-alpha and TNF-beta genetic polymorphisms and sarcoidosis, by showing that the TNF-beta gene A252G polymorphism might be a potential risk factor for the development of sarcoidosis.