OP024 Agreement among central readers in the evaluation of endoscopic disease activity in Crohn's disease

Abstract

of a biomarker test that can identify and stratify young IBD patients. Methods Samples from well-characterized patients were collected from 15 North American GI centers. Median age was 15 (IQR: 13-16). Samples from 251 patients were used: 147 Crohn's disease (CD), 47 ulcerative colitis (UC) and 57 non-IBD disease controls. A combination of serological markers (ASCA-IgA, ASCA-IgG, ANCA, pANCA, anti-OmpC, anti-Fla2, anti-FlaX and anti-CBir1), four gene variants (ATG16L1, NKX2-3, ECM1, and STAT3) and five inflammatory markers (CRP, SAA, ICAM, VCAM, and VEGF) were used in this evaluation. Identification of IBD, CD, and UC and was made with the aid of a machine learning model. Sensitivity, specificity, NPV, PPV and accuracy statistics were calculated for both the IBD vs. Non-IBD component of the diagnostic model, and separately for the CD vs. UC component (for patients called IBD by the model). Results The multi-marker biomarker diagnostic model performed in classifying IBD, CD and UC in pediatric patients as reported in Table 1. We observed a sensitivity of 86.1% and a specificity of 86% for identifying young adults with IBD. The sensitivity and specificity for classifying CD in patients called IBD by the model was 91.9% and 75.8%, respectively. UC sensitivity and specificity was 82.1% and 90.5%, respectively. Diagnostic accuracy of the biomarkers was 86.1% for IBD vs. non-IBD, 88.2% for CD and 88.9% for UC. The IBD NPV and PPV were 64.5% and 95.4% respectively. CD NPV and PPV were 73.5% and 92.7%, respectively. UC NPV and PPV were and 95.5% and 67.6%, respectively. Conclusion Our results demonstrate that a combination of serological, genetic, and inflammatory markers may be utilized for classifying non-IBD, CD, and UC in the young adult patient population. Further studies are required to further investigate the clinical utility of this biomarker test. Table 1