IL18 and rheumatoid arthritis: Meta-analysis showed no statistic association between RA and the IL-18 rs1946518 polymorphism in all genetic models (additive model: OR=0.752,95%CI=0.562-1.006; dominant model: OR=0.730, 95%CI =0.479-1.113; recessive model: OR=0.537, 95%CI=0.271-1.064).