Association between tumor necrosis factor-α (TNF-α) promoter-308 G/A and response to TNF-α blockers in rheumatoid arthritis: a meta-analysis

Tumor necrosis factor (TNF)-alpha promoter -308G/A polymorphism has been shown to be associated with high TNF-alpha production and poor response to anti-TNF-alpha treatment. However, not all patients show a good response to TNF-alpha antagonists, so this association remains controversial. This study was designed to investigate whether TNF-alpha promoter -308 G/A polymorphism is associated with responsiveness to anti-TNF therapy in rheumatoid arthritis (RA) patients. The 28-joint count Disease Activity Score (DAS) 28 or the American College of Rheumatology (ACR) improvement criteria 20 were used to measure patient response. A meta-analysis was performed. Pooled ORs and 95 % CIs were calculated by both dominant and recessive genetic models. Fifteen studies with a total of 2127 patients were included in this meta-analysis. The results showed that patients with the G allele responded better to the treatment (OR = 1.87, 95 % CI 1.26-2.79). A subanalysis showed similar results. Based on the results of this meta-analysis, RA patients with the TNF-alpha promoter -308 G allele respond better to TNF-alpha antagonist treatment, suggesting that this allele plays a major role in anti-TNF-alpha treatment response.