Study Of The Association Of IL-17A And IL-17F Polymorphisms With Susceptibility To Behcet's Disease And Vogt-Koyanagi-Harada Syndrome In Chinese Han Population

OBJECTIVE: Interleukin (IL)-17 has been shown to play an important role in certain autoimmune diseases. The present study was performed to investigate the association of IL-17A and IL-17F gene polymorphisms with two autoimmune uveitis entities, Vogt-Koyanagi-Harada (VKH) syndrome and Behcet's disease (BD), in a Chinese Han population.METHODS: A total of 362 BD patients, 385 VKH patients and 412 controls were genotyped for IL-17A/rs2275913 and IL-17F/rs763780 using polymerase chain reaction restricted fragment length polymorphism. The Chi-square test was performed to compare allele and genotype distributions. A binary logistic regression analysis was used to assess the influence of the gender on the association of IL17 polymorphisms with BD.RESULTS: The result showed that the genotype and allele distribution of the two SNPs in all subjects were in Hardy-Weinberg equilibrium. A significantly decreased frequency of IL-17F/rs763780 C allele (P=0.006, Pc= 0.036,) and an increased frequency of TT genotype (P=0.005, Pc=0.030) were observed in VKH patients as compared with normal controls. There was neither association of the two tested SNPs with BD, nor association after adjusting gender ratio in this disease. Stratification analysis failed to find any association of extraocular manifestations of two uveitis entities and the tested two SNPs.CONCLUSIONS: The C allele and TT genotype of rs763780 in IL-17F gene is probably associated with the protection or susceptibility to VKH syndrome. The tested two IL-17 SNPs are not associated with Behcet's disease.