P0219Real-Time Calprotectin for Real-World IBD: Clinical Validation of a point-of care, app based Calprotectin Test

Background Fecal calprotectin (FCal) is a key non-invasive biomarker for diagnosing inflammatory bowel disease (IBD), differentiating it from functional disorders, and monitoring disease activity. However, routine laboratory assays typically require 3–5 days, delaying diagnostic clarification, escalation of therapy, and adherence to treat-to-target principles. A rapid, app-based point-of-care (POC) FCal test that produces results within minutes may streamline patient pathways, enable same-visit decision-making, and improve clinical efficiency. We aim to validate the diagnostic accuracy of a POC FCal device [QuantOn Cal®] for distinguishing IBD from irritable bowel syndrome (IBS) and for assessing clinical and endoscopic disease activity in established IBD in a real-world scenario. Methods This prospective study included consecutive patients presenting with gastrointestinal symptoms who underwent POC FCal testing during their initial visit over 3 years. Final diagnoses of IBS or IBD were confirmed after ≥6 months of structured clinical follow-up. In patients with IBD, POC FCal values were correlated with clinical activity (Truelove & Witts for ulcerative colitis [UC] and CDAI for Crohn’s disease [CD]). Correlation with endoscopic activity (Mayo endoscopic subscore 0 vs 1–3 for UC; SES-CD for CD) was done when available. Diagnostic accuracy was assessed using ROC analysis. Results Among 1,292 patients, 582 had IBS and 710 had IBD. Mean FCal levels were 37 µg/g in IBS and 473 µg/g in IBD. Mean FCal in patients with UC was 156 µg/g in clinical remission vs 938 µg/g in active disease and 177 vs 908 µg/g in patients with CD respectively. Endoscopic correlation was available in 219 patients with UC (197 active disease and 22 in remission) and 117 patients with CD (79 active disease and 38 in remission). Mean FCal in patients with UC was 149 vs 895 µg/g in endoscopic remission vs activity and 190 vs 812 µg/g in patients with CD respectively. An FCal threshold of 105 µg/g differentiated remission from active IBD with an AUROC of 0.939. Conclusion This app-based POC FCal test demonstrates excellent diagnostic accuracy for distinguishing IBD from IBS and shows strong correlation with clinical and endoscopic activity across UC and CD in a real-world setting. Immediate availability of reliable inflammatory markers enables same-visit therapeutic decisions, reduces diagnostic delays, and supports timely implementation of treat-to-target strategies. Integration of POC FCal into routine practice may substantially improve the efficiency, responsiveness, and overall quality of IBD care. Conflict of interest: Dr. Nagarajan, Kayal Vizhi: No conflict of interest Indi, Supriya: No conflict of interest Reddy, Shravani: No conflict of interest Bang, Anand: No conflict of interest Yelsangikar, Amit: No conflict of interest Bhat, Ramya: No conflict of interest Chandy, Anila: No conflict of interest Nagar, Anupama: No conflict of interest Bhat, Naresh: No conflict of interest