Objectives: Endoscopic mucosal healing is a key endpoint for the treatment of ulcerative colitis (UC). The role of microscopic activity in predicting disease relapse has not been fully assessed. We aimed to investigate the predictive role of serologic and histologic markers on disease relapse in UC patients with endoscopically inactive disease.
Methods: Adult UC patients with endoscopically inactive disease (Mayo 0) and a 12-month follow-up between 2008 and 2011 were retrospectively included. An expert pathologist evaluated all colonic biopsies for histologic activity (Geboes score) and the presence of basal plasmacytosis. Blood samples collected around the time of endoscopy were analyzed. Disease relapse, defined as a clinical Mayo score ≥3, was documented during follow-up.
Results: The study cohort consisted of 75 patients (53% men, median age 47 years). Despite normal endoscopy, histology showed inflammatory activity with a Geboes score ≥3.1 in 40% and basal plasmacytosis in 21% of patients. At 12 months, clinical relapse was observed in 20% (n=15) of patients. Presence of basal plasmacytosis (P=0.007) and a Geboes score ≥3.1 (P=0.007) were predictive of disease relapse. Using multivariate analysis, the presence of basal plasmacytosis was predictive of clinical relapse (odds ratio (OR) 5.13 (95% confidence interval (CI): 1.32-19.99), P=0.019), whereas the use of biologicals at endoscopy favored remission (OR 0.24 (95% CI: 0.05-1.01), P=0.052).
Conclusions: We demonstrated that the presence of basal plasmacytosis predicts UC clinical relapse in patients with complete mucosal healing. We recommend closer follow-up and optimization of medical therapy in patients with basal plasmacytosis.