Validation of the Odesa Criteria 2026 for Autoimmune Pancreatitis

The study uses an ambispective design, including both retrospective and prospective data collection. Autoimmune pancreatitis (AIP) remains a diagnostic challenge due to its heterogeneous clinical presentation and overlap with pancreatic cancer and other inflammatory conditions. The Odesa Criteria 2026 (OC26) were developed as a flexible, domain-based point scoring system integrating four diagnostic domains: morphology, serology, clinical features, and histology. Each domain contributes weighted points toward a total diagnostic score, enabling structured and reproducible assessment across diverse patient phenotypes. This ambispective observational study evaluates the diagnostic performance of OC26 in real-world clinical practice. The study assesses sensitivity, specificity, predictive values, likelihood ratios, and overall diagnostic accuracy using final clinical diagnosis as the reference standard. Additional analyses include interobserver agreement for domain scoring, diagnostic performance of individual domains, ROC curve analysis for the total OC26 score, and determination of the optimal diagnostic cut-off. The study aims to validate OC26 as a practical, scalable, and reproducible diagnostic tool for autoimmune pancreatitis, supporting its implementation in routine clinical workflows and future international guideline development.