The aim of this study was to determine whether the functional interleukin-4 (IL-4) -590 C/T, IL-4 receptor (IL-4R) 1902 G/A, IL-18 -607 C/A, and -137 G/C polymorphisms polymorphisms confer susceptibility to rheumatoid arthritis (RA).
Meta-analysis was conducted on the associations between these IL-4, IL-4R, and IL-18 polymorphisms and RA.
A total of 12 comparative studies were included in this meta-analysis. Meta-analysis of the IL-4 -590 C/T polymorphism showed an association in all study subjects and Europeans (OR for the TT genotype = 2.280, 95% CI = 1.315-3.952, p = 0.003; OR = 2.139, 95% CI = 1.089-4.199, p = 0.027). However, meta-analysis showed no association between RA and the IL-4R 1902 G allele in all study subjects and Europeans. Meta-analysis showed no association between RA and the IL-18 -607 C allele (OR = 1.159, 95% CI = 0.967-1.387, p = 0.110). Meta-analysis of the IL-18 -137 G/C polymorphism revealed no association between RA and the IL-18 -137 G/C polymorphism.
This meta-analysis demonstrates that the IL-4 -590 T/C polymorphism is associated with susceptibility to RA in Europeans, but the IL-4R + 1902 G/A, IL-18 -607 C/A and -137 G/C polymorphisms are not associated with RA.