Association Of MIF-173, IL-4R+1902, IL-6-174 Genetic Polymorphisms With The Risk Of Rheumatoid Arthritis In Northwest Chinese Population.

Background:Rheumatoid arthritis(RA) is a complex multi-factorial diseases caused by environmental influences and an unknown number of predisposing genes. The objective of this research is to perform a genetic association of genetic polymorphisms of the macrophage inhibitory factor(MIF),interleukin-4 receptor (IL-4R) and IL-6 genes with the susceptibility and severity of RA in Northwest Chinese population,seeking evidence for involvement in the onset or the erosive outcome of RA.Material and Methods:We enrolled 129 RA patients and 249 normal controls. Polymerase chain reaction was used to identify the MIF-173(G-C),IL4R+1902(A-G), IL6-174(G-C) polymorphisms,followed by restriction-enzyme digestion and agarose gel electrophoresis.The data were analyzed by the chi-square test,and calculating odds ration(OR) and 95%confidence intervals(CI).Results:The genotype of MIF-173,when G/C vs.G/G,there was significant differences between the RA and control groups(x~2=4.420,Pearson's P=0.036 OR =1.695,95%CI=1.034～2.778),when C/C vs.G/G,the differences were not significant.(x~2=0.432,Pearson's P=0.511 OR=1.277,95%CI=0.615～2.653).The genotype and allele distributions of IL4R+1902 showed the differences were not significant(P＞0.05).There were significant differences between the RA and control groups of the IL6-174G/C(P＜0.05).Conclusion:We found a significant association of the allele IL6-174C and carriers of the allele C of MIF-173 with increased risk of RA in the Chinese population from northwest China..But the polymorphism of IL-4R+1902 gene detected did not indicate an association with the risk of RA in the investigated population.