Fecal Calprotectin Combined with Blood Inflammatory Biomarkers Enhances Diagnostic Evaluation and Supports Mucosal Healing Assessment in Pediatric Crohn’s Disease

Pu Li,1,* Yu Xu,1,* Yingqin Zhou,2 Ruizhuang Sun,1 Zhidong Gu,1,3 Jun Meng1,3 1Department of Laboratory Medicine, Ruijin-Hainan Hospital, Shanghai Jiao Tong University School of Medicine (Hainan Boao Research Hospital), Ruijin, Hainan, People’s Republic of China; 2Department of Clinical laboratory, Pujiang Hospital, Minhang Area, Shanghai, People’s Republic of China; 3Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China*These authors contributed equally to this workCorrespondence: Jun Meng, Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 201821, People’s Republic of China, Tel +86 13916232907, Email [email protected] Zhidong Gu, Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 201821, People’s Republic of China, Tel +86 13801653534, Email [email protected]: Previous small-sample study suggested that fecal calprotectin (FC) combined with blood inflammatory biomarkers may aid in Crohn’s disease (CD) diagnosis. This study aimed to validate the FC’s diagnostic and mucosal healing assessment value of FC and a noninvasive composite index in pediatric CD.Patients and Methods: Patients aged 2– 17 years who underwent ileocolonoscopy for suspected or established CD were enrolled. Based on endoscopy, participants were classified into three groups: controls (functional gastrointestinal disorders), MH (mucosal healing, SES-CD < 3, indicating minimal or absent visible inflammation), and ML (mucosal lesions, SES-CD ≥ 3). Fecal and blood samples were collected before endoscopy. Group differences were assessed using Kruskal–Wallis/Dunn’s tests; correlations were evaluated via Spearman coefficients; ROC analysis was used to assess diagnostic performance. A composite index was constructed by weighting CRP, ESR, and IL-6 based on their correlations with FC.Results: Among 123 participants, FC levels significantly differed across groups (P