The assessment of segmental healing by the Modified Mayo Endoscopic Score (MMES) complements the prediction of long-term clinical outcomes in patients with ulcerative colitis.

Abstract

Current endoscopic scoring systems for ulcerative colitis (UC) do not consider the extent of mucosal inflammation. The modified Mayo endoscopic score (MMES) was developed to detect segmental endoscopic improvement. We evaluated the ability of the MMES to predict long-term clinical outcomes and compared it to the widely used Mayo endoscopic subscore (MES). Consecutive patients with moderate to severe UC starting biological therapy were enrolled between January 2014 and September 2017 in this prospective observational study. A clinical and endoscopic evaluation was performed at baseline and at week 8/14. A modified Mayo score was used to grade clinical activity, MES and MMES were used to evaluate endoscopic activity. Patients were divided into 3 groups according to the evolution of endoscopic activity, namely endoscopic improvement (MES ≤ 1), segmental endoscopic response only (MES > 1, but decrease in MMES ≥ 30%) or no endoscopic response (all others). Over the follow-up period clinical relapse-, discontinuation- and colectomy-free survival were assessed. A total of 150 patients were included (48% female, median age 42 years, median disease duration 7 years) with a median follow-up of 61 months. We identified 69 patients with endoscopic improvement, 27 with segmental endoscopic response and 54 without endoscopic response. Patients with segmental endoscopic response showed intermediate long-term clinical outcomes as compared to the other two groups (log rank p = 0.003 for clinical relapse-, and p < 0.001 for both discontinuation- and colectomy-free survival). The MMES exhibited a benefit in predicting long-term outcome in UC even though endoscopic improvement remains the strongest predictor.