DOP63 The Toronto IBD global endoscopic reporting (TIGER) score is well correlated with fecal calprotectin and IBD Disk in Ulcerative Colitis patients

Zittan, E.(1,2);Steinhart, A.H.(3); Aran, H.(1);Milgrom, R.(3); Koifman, E.(1);Gralnek, I.M.(1); Zelber-Sagi, S.(2); Silverberg, M.S.(3)

(1)Emek Medical Center, Ellen and Pinchas Mamber Institute of Gastroenterology and Liver Diseases- IBD Unit, Afula, Israel;(2)University of Haifa, School of Public Health- Faculty of Social Welfare and Health Sciences, Haifa, Israel;(3)Mount Sinai Hospital- Zane Cohen Centre for Digestive Diseases- University of Toronto, Division of Gastroenterology- Department of Medicine, Toronto, Canada

Background

Commonly used endoscopic indices in IBD lack ability to provide overall disease burden and severity, generate low inter-observer agreement, and demonstrate incomplete validation of some scores. We developed a new endoscopic reporting tool, the Toronto IBD Global Endoscopic Reporting (TIGER) score for Crohn’s disease (CD) and ulcerative colitis (UC) patients. The aim of our study was to compare the usability and validity of the TIGER score against fecal calprotectin (FC), C-reactive protein (CRP) and IBD DISK score in UC patients.  

Methods

A cohort of 53 UC patients participated in the study.  Blinded IBD experts reviewed and graded ileocolonoscopy videos. In the validation phase, the TIGER score was compared to (1) the Mayo endoscopic score serving as a reference standard and; (2) inflammatory biomarkers FC, CRP and; (3) IBD Disk.

Results

Inter-observer reliability of the TIGER score per segment between reviewers was excellent, Interclass Correlation Coefficient (ICC)=0.94; [95%CI: 0.92-0.96]. For categorized TIGER score, lowest overall agreement was 96.6% [95%CI: 93.5-98.6] and lowest kappa 0.91 [95%CI: 0.84-0.98], reflecting excellent agreement.  Overall agreement per segment between Mayo endoscopic score and TIGER was 84% [95%CI:74%-90%] and kappa coefficient 0.60 [95%CI: 0.42-0.808]. Per subject analysis for UC yielded overall agreement of 80% [95%CI: 64-91] and kappa coefficient 0.44 [95%CI: 0.14-0.75]. There was a significant correlation between TIGER and FC (rs = .794, p < .0001). There was a significant correlation between TIGER and IBD Disk (rs = .613, p < .0001). As expected, there was a lower correlation between TIGER score and CRP (rs = .309, p < .0850) in UC patients.

Conclusion

The TIGER endoscopic score demonstrates significant correlation with FC and IBD disk score in ulcerative colitis patients and thus can be used as a reliable and simple endoscopic score for UC patients to capture overall endoscopic disease burden.