Supplementary Material for: Low Back Pain and Sacroiliitis on Cross-Sectional Abdominal Imaging for Axial Spondyloarthritis Diagnosis in Inflammatory Bowel Diseases

Background: Joint damage is the most frequent extraintestinal manifestation in inflammatory bowel disease (IBD). Aims: The aim of the study was to assess the value of low back pain (LBP) associated with sacroiliitis on abdominal imaging for the diagnosis of spondyloarthritis (SpA) in IBD. Methods: We used a questionnaire assessing rheumatological symptoms for all patients with abdominal computed tomography (CT) and magnetic resonance enterography (MRE). Sacroiliitis was assessed on available CT and MRE. Patients were classified as axial SpA according to the Assessment of SpondyloArthritis International Society criteria. Results: Fifty-one patients completed the questionnaire and performed both exams. LBP was present in 27 patients (52.9%), and 10 (19.6%) had an inflammatory component. Sacroiliitis was reported in 12 patients (23.5%), and 6 of them suffered from LBP. Among the 20 patients referred to the rheumatologist, 11 patients suffered from LBP. One patient was HLA-B27 positive and presented sacroiliitis. For the last 10 patients, none of them had a sacroiliitis, and 2 patients were negative for HLA-B27. Conclusion: An axial SpA has been diagnosed in 11.8% of IBD patients undergoing cross-sectional imaging, whereas one-fifth had inflammatory LBP, and sacroiliitis was observed in one-quarter of them. To optimize the diagnosis of axial SpA, HLA-B27 testing might be required for patients with both IBD and LBP, but this will require further investigation before its implementation in routine practice.

研究背景：关节损害是炎症性肠病（inflammatory bowel disease，IBD）最常见的肠外表现。
研究目的：本研究旨在评估腹部影像学检查中伴骶髂关节炎（sacroiliitis）的腰痛（low back pain，LBP）对炎症性肠病患者脊柱关节炎（spondyloarthritis，SpA）的诊断价值。
研究方法：本研究针对接受腹部计算机断层扫描（computed tomography，CT）与磁共振小肠造影（magnetic resonance enterography，MRE）的所有患者，采用评估风湿性症状的问卷开展调研。对可获得的CT与MRE影像进行骶髂关节炎评估，并依据国际脊柱关节炎评估协会（Assessment of SpondyloArthritis International Society）标准将患者归类为轴性脊柱关节炎患者。
研究结果：共计51名患者完成问卷并完成两项检查。其中27名患者（52.9%）存在腰痛，10名（19.6%）伴有炎性成分。12名患者（23.5%）检出骶髂关节炎，其中6名存在腰痛。转诊至风湿科医师的20名患者中，11名存在腰痛。1名人类白细胞抗原B27（HLA-B27）阳性患者检出骶髂关节炎。剩余10名患者均未检出骶髂关节炎，其中2名HLA-B27检测为阴性。
研究结论：接受横断面影像学检查（cross-sectional imaging）的炎症性肠病患者中，11.8%被确诊为轴性脊柱关节炎；其中五分之一伴有炎性腰痛，四分之一检出骶髂关节炎。为优化轴性脊柱关节炎的诊断，对于同时患有炎症性肠病与腰痛的患者，可能需要开展HLA-B27检测，但该方案在临床常规应用前仍需进一步研究验证。