Ab0941 Fecal Calprotectin in Japanese Patient With Spondyloarthritis

Background: Fecal calprotectin is a well-established predictive marker for inflammatory bowel disease activity, but this marker has been reported to be elevated in spondyloarthritis (SpA) patients even in the absence of inflammatory bowel disease or any other chronic intestinal disease [1]. Fecal calprotectin may be useful as an indicator of treatment choice as well as for assessing disease activity in SpA; however, reference values of fecal calprotectin may vary by race and type of SpA. Most of these data were reported from Western countries, and data on Japanese patients with SpA are limited. Objectives: To determine the differences in fecal calprotectin levels among Japanese SpA types and non-SpA rheumatic and musculoskeletal disease (RMD). Methods: Twenty-three patients with SpA and 23 patients with other RMDs at Kagawa University Hospital from October 2020 to December 2023 were included in the study. All subjects in this study were over the age of 18. Fecal calprotectin was measured by fluorescence enzyme immunoassay (cutoff value 50μg/g). Subjects complicated with inflammatory bowel disease were excluded. We firstly compared fecal calprotectin levels in patients with SpA and patients with other RMDs. Additionally, the association between clinical characteristics and fecal calprotectin levels in patients with SpA was analyzed. We used the Mann–Whitney U test to compare fecal calprotectin levels. All P values were 2-sided, and a P value of <0.05 was considered significant. Results: Of the 23 patients with SpA included in the study, 8 had ankylosing spondylitis and 9 had psoriatic arthritis. The other RMDs without SpA included 17 cases of Behcet's disease and 2 cases of systemic lupus erythematosus. In the analysis of clinical characteristics, SpA and other RMDs groups showed differences in C-reactive protein levels and age, but not between ankylosing spondylitis and other SpAs. Fecal calprotectin level in patients with SpA was significantly higher than in other RMDs patients (168 μg/g; IQR 38-444 μg/g vs. 36 μg/g; IQR 13-96 μg/g, p=0.0044). Patients with ankylosing spondylitis tended to have higher fecal calprotectin level than patients with other SpAs (435 μg/g; IQR 142-985 μg/g vs. 101 μg/g; IQR 36-269 μg/g, p=0.0707). Conclusion: Among Japanese patients, fecal calprotectin level in patients with SpA was significantly higher than that in other RMDs patients. Because fecal calprotectin levels in patients with SpA are higher than reference values in healthy individuals and in other rheumatic diseases, caution must be exercised in the interpretation of this biomarker used to screen for inflammatory bowel disease complications at determining therapeutic agents. Further study is needed to evaluate the significance of fecal calprotectin measurement in SpA. REFERENCES: [1] Simioni J, Skare TL, Campos APB, et al. Fecal Calprotectin, Gut Inflammation and Spondyloarthritis. Arch Med Res. 2019;50(1):41-46. Acknowledgements: NIL. Disclosure of Interests: None declared.