A Simplified Geboes Score for Ulcerative Colitis.

Background and Aims: The original Geboes Score [OGS] is the most commonly used histological score in ulcerative colitis [UC], but rather complicated to use in daily clinical practice. The aim of this study was to develop a Simplified Geboes Score [SGS] and to compare it with the OGS in patients newly diagnosed with UC. Methods: All patients diagnosed with UC at a tertiary referral centre between 2005 and 2010, who had serial colonoscopies with biopsies, were retrospectively included. The 5-year endoscopic/histological evolution after diagnosis was recorded. Histological activity was scored by an experienced inflammatory bowel disease pathologist and three trained readers using the OGS and also the new SGS that only includes variables linked to active inflammatory disease. The correlation between endoscopic and histological activity and the histological inter-observer agreement were measured. Results: A total of 528 slides from 339 colonoscopies of 103 UC patients were reviewed. Forty [12%] colonoscopies presented Mayo 0, 74 [22%] Mayo 1, 107 [31%] Mayo 2 and 118 [35%] Mayo 3. Active microscopic disease [>= 3.1 in both scores] was described in 10/40 [25%] patients who were in complete endoscopic remission [Mayo 0], and 62/74 [84%] with mild endoscopic lesions [Mayo 1]. The correlation analysis between endoscopy and OGS/SGS did not show significant differences between the histological scores. The inter-observer agreement was moderate for all the grades of the SGS. Conclusions: The assessments of histological activity based on the OGS and the SGS were comparable in newly diagnosed active UC patients. Further prospective validation should now be done to replace the OGS with the SGS.