Associations between TNF-α -308 A/G and lymphotoxin-α +252 A/G polymorphisms and susceptibility to sarcoidosis: A meta-analysis

Several studies have examined the effects of the tumor necrosis factor-α (TNF-α) -308 A/G and lymphotoxin-α (LT-α) +252 A/G polymorphisms on susceptibility to sarcoidosis, showing mixed results. The purpose of this study was to examine whether the TNF-α -308 A/G and LT-α +252 A/G polymorphisms confer susceptibility to sarcoidosis. We did a literature search from MEDLINE and EMBASE indices, and conducted a meta-analysis examining the association between TNF-α -308 A/G and LT-α +252 A/G polymorphisms and sarcoidosis. A total of 13 separate comparisons including 1,396 patients with sarcoidosis and 2,344 controls were considered in our meta-analysis. The meta-analysis revealed a significant association between the TNF-α -308 A allele and sarcoidosis (odds ratio [OR] = 1.480, 95 % confidence interval [CI] 1.057-2.073, p = 0.002). Stratification by ethnicity indicated an association between the TNF-α -308 A allele polymorphism and sarcoidosis in Europeans (OR = 1.445, 95 % CI = 1.010-2.065, p = 0.044), but not Asians (OR = 4.693, 95 % CI = 0.548-40.29, p = 0.158). The results also showed a significant association between the LT-α +252 G allele and sarcoidosis (OR = 1.266, 95 % CI = 1.048-1.528, p = 0.014). Stratification by ethnicity indicated an association between the LT-α +252 G allele and sarcoidosis in Europeans (OR = 1.307, 95 % CI = 1.045-1.635, p = 0.019), but not in Asians (OR = 1.169, 95 % CI = 0.824-1.660, p = 0.381). Our meta-analysis demonstrates that the TNF-α -308 A/G and LT-α +252 A/G polymorphisms are associated with susceptibility to sarcoidosis in an European population.