Association between Interleukin-6 Gene Polymorphisms and Rheumatoid Arthritis in Chinese Han Population: A

The aim of this study was to investigate the possible association in the interleukin-6 (IL-6) gene withRheumatoidarthritis(RA)inChineseHanpopulationfromShandongProvince.TargetregionsofIL-6genewere amplified by polymerase chain reaction (PCR) and genotyped. A logistic regression analysis wasperformed to detect potential associations in our case-control sample, the odd ratio(OR) and 95%confidence intervals(CIs) were calculated. Furthermore, we systematically tracked all the published studiesinthefieldandperformedameta-analysisforthesinglenucleotidepolymorphisms(SNPs)understudy.256RApatientsand331healthycontrolswererecruitedintothecase-controlstudy.Wefoundallelefrequenciesofrs1800795,rs1800797andrs1474347inRApatientsdifferfromcontrolsubjects(P50.016,0.024,0.020,respectively). Significant difference was observed in haplotype frequencies of GCCGCT between RApatients and controls (P 5 0.0001, OR 5 4.066, 95%CI 5 1.891 , 8.746), while GGCGCT frequencies wasfound lower in RA than controls (P50.006, OR 5 0.669, 95%CI 5 0.501 , 0.894). The results of themeta-analysisshowedassociationpolymorphismwithintheIL-6promoterwithRA.Thesefindingssuggestthat rare IL-6 gene polymorphisms may associate with RA susceptibility in Han Chinese populations;however further studies are needed to assess the validity of the association of IL-6 with RA.