Beyond Neutrophils for Predicting Relapse and Remission in Ulcerative Colitis

Background and Aims This study examines colonic histological features in ulcerative colitis [UC] in endoscopic remission to determine which cell types and biopsy sites best predict a patient's likelihood of remaining in remission. Methods This is a retrospective chart, endoscopy and histology review of 166 patients with UC in endoscopic remission followed in a single inflammatory bowel disease practice over a median of 6 years [range, 2-11 years]. Clinical remission was based on global physician assessment and colonoscopy reports, and clinical relapse on chart review. Histological features of previous injury and also number and location of plasma cells and eosinophils were assessed. We evaluated all of these features semi-quantitatively using a standard set of illustrations for the grade to maintain consistency. Multiple logistic regression and survival analyses were used to identify features associated with relapse. Results Clinical relapse occurred in 44 patients. Ulceration, especially in the left colon, was highly predictive of relapse. In the absence of acute inflammation of ulceration, the variables most predictive of relapse were increased plasma cells in the basal 20% of the lamina propria, and eosinophils in the left colon. The variable most predictive of persistent remission was the presence of intra-epithelial eosinophils whether in the surface epithelium or within crypts, especially in the right colon. Lamina propria eosinophils [grade > 2] throughout the colon predicted relapse. Conclusion In the absence of neutrophils or ulceration, left-sided plasmacytosis in the basal 20% of the lamina propria and increased lamina propria eosinophils provide the best indicators of relapse in UC in clinical and endoscopic remission.