P0447Cross-sectional study of fecal calprotectin in predicting endoscopic activity in patients with Crohn’s Disease

Abstract Background To evaluate the predictive efficacy of fecal calprotectin (FC) for endoscopic activity in patients with Crohn’s Disease (CD). Methods A cross-sectional study was conducted and patients diagnosed with CD at Peking Union Medical College Hospital between June 2023 and September 2025 were enrolled consecutively. Data collected included general information, laboratory tests hemoglobin (HGB), platelet (PLT), FC, high-sensitivity C-reactive protein (hsCRP), erythrocyte sedimentation rate (ESR), and endoscopic results. FC levels were measured with latex-enhanced turbidimetric immunoassay (LETIA). Endoscopic activity was defined as a Simplified Endoscopic Score for Crohn’s Disease (SES-CD) 2. Patients were divided into an endoscopically active group and an endoscopic remission group based on endoscopic activity. Spearman correlation analysis was used to assess the correlation between FC and endoscopic activity, and receiver operating characteristic (ROC) curve was used to evaluate the diagnostic efficacy of FC. Results A total of 90 patients were enrolled, including 65 males and 25 females with the age of 30 (22,41) and disease course 4.0 (0.5, 8.0). 71 patients (78.9%) had ileocolonic disease involvement (L3), and 55 patients (61.1%) were using biologics. 69 patients in endoscopic activity were assigned to the endoscopically active group, while the remaining 21 were assigned to the endoscopic remission group. There was no statistically significant difference in general characteristics such as age and gender between the two groups (all P 0.05). HGB was significantly lower in the endoscopically active group, while PLT, hsCRP, ESR, and FC were significantly higher than endoscopic remission group (all P 0.05). Among the 90 CD patients, FC levels were significantly correlated with endoscopic activity (ρ = 0.494). ROC curve analysis indicated that the area under the receiver operating characteristic curve for FC in predicting endoscopic activity was 0.836 (95% CI: 0.737–0.935), with a sensitivity of 0.725, specificity of 0.952, and accuracy of 0.778 at the optimal FC cutoff value of 153.8 μg/g. FC outperformed hsCRP and ESR. Conclusion FC measured by LETIA demonstrated certain efficacy in predicting endoscopic activity in CD and would assist in efficient clinical monitoring of CD patients. Conflict of interest: Mr. Zhou, Yuzhe: No conflict of interest Xia, Qianqian: No conflict of interest Guo, Ye: No conflict of interest Han, Wei: No conflict of interest Tang, Xiaoyan: No conflict of interest Lyu, Hong: No conflict of interest Shu, Huijun: No conflict of interest Ruan, Gechong: No conflict of interest Yang, Hong: No conflict of interest Qian, Jiaming: No conflict of interest