Meta-analysis demonstrates association between TLR polymorphisms and rheumatoid arthritis

We investigated whether Toll-like receptor (TLR) polymorphisms confer susceptibility to rheumatoid arthritis and whether they influence clinical characteristics of rheumatoid arthritis. Studies were considered relevant for our meta-analysis if at least two comparisons of an issue were available. Eleven studies with 2078 patients with rheumatoid arthritis and 2581 controls were included, encompassing European and Asian studies. Meta-analysis of three European studies showed no significant association between the TLR4 Asp299Gly (rs4986790) polymorphism and rheumatoid arthritis (odds ratio = 0.897, 95% confidence interval = 0.734-1.096, P = 0.289). One Turkish study showed a significant difference between TLR9 rs187084 allele frequencies and rheumatoid arthritis patients and controls, while another study revealed a significant association between rheumatoid factor and TLR8 rs5741883. A Korean study on the numbers of guanine-thymine [(GT)(n)] repeats in intron II of the TLR2 gene found a significantly higher S-allele frequency in rheumatoid arthritis patients than in controls (30.3 vs 23.0%). Overall findings for the meta-analysis including all the studies conclude that TLR polymorphism is associated with development and clinical characteristics of rheumatoid arthritis in Asian and Middle East populations.