Endoscopic features and genetic background of inflammatory bowel disease complicated with Takayasu arteritis

Background and Aim Takayasu arteritis (TA) is occasionally complicated with inflammatory bowel disease (IBD). This study assessed the endoscopic and genetic features of IBD complicated with TA (IBD-TA). Methods This study retrospectively reviewed the clinical charts of 142 TA patients (14 men and 128 women; median age 48.5 years [range, 18–97 years]). Human lymphocyte antigen (HLA) types and a single-nucleotide polymorphism rs6871626 in the IL12B gene were assessed in 101 and 81 patients with TA, respectively. Results Inflammatory bowel disease was diagnosed in 13 (9.2%) of the 142 patients. The endoscopic features of IBD-TA at initial diagnosis (n = 8) showed discontinuous and focal mucosal inflammations (n = 7, 87.5%), and only one case was diagnosed as ulcerative colitis (UC) at the first colonoscopy. In the genetic comparison of HLA class I between TA patients with IBD and those without IBD, HLA-B*52:01 and C*12:02 were more frequent in the IBD-TA group (P = 0.001 and P = 0.009, respectively). Meanwhile, HLA-DRB-1*15:02, DQA-1*01:03, DQB-1*06:01, and DPB-1*09:01 as HLA class II were positively associated with IBD-TA (P = 0.004, P = 0.019, P = 0.019, and P = 0.002, respectively). IL12B rs6871626 did not show an association with IBD-TA compared with that with TA without IBD. Conclusions The endoscopic findings of IBD-TA at initial diagnosis were atypical for UC or Crohn's disease. IBD-TA possessed the HLA haplotype, which had a susceptible effect on UC.