Genetic Variations Of IL17F And IL23A Show Associations With Behcet’s Disease And Vogt-koyanagi-harada Syndrome

ObjectiveAccumulating evidences showed that Th17 cell or Th17 cell-related genes has emerged as a major player in autoimmune or autoinflammatory diseases such as uveitis. This study aimed to investigate the associations of IL17 A, IL17F, IL23A, and IL23 R copy number variants(CNVs) with Vogt-Koyanagi-Harada(VKH) syndrome and Behcet’s disease(BD) and the possible mechanisms involved.MethodsTaq Man real-time polymerase chain reaction assay was used for genotyping of copy number variant. Cell proliferation was measured by colorimetric assay. Protein level was examined by ELASA.ResultsIncreased frequencies of more than 2 copies of IL17F and IL23A were found in BD patients as compared with controls(IL17F: P=4.17×10-8,OR=2.2; IL23A: P=2.86×10-11,OR=2.8, respectively). A similar result was found for VKH syndrome(IL17F: P=2.84×10-13, OR=2.7; IL23A: P=4.46×10-17, OR=3.4, respectively). Interestingly, the association of IL17F and IL23A with BD was found only in male patients(IL17F: P=1.06×10-6,OR=2.3; IL23A: P=3.81×10-8 OR=2.8, respectively), but not in female patients. No association of CNVs in IL17 A and IL23 R was found for BD and VKH syndrome. IL17F protein levels were correlated positively with gene copy numbers(P=3.43×10-7). Individuals with high IL17F copies showed enhanced peripheral blood mononuclear cells(PBMC) proliferation(P=5.67× 10-3).ConclusionsHigh gene copy numbers of IL17F and IL23A were associated with BD and VKH syndrome. Enhanced IL17F protein production and PBMC proliferation were associated with high IL17F copy numbers.