DOP050. Mucosal healing in ulcerative colitis: Do Mayo 0 and 1 scores really have the same prognostic value? A prospective observational cohort study
M. Barreiro-de Acosta, N. Vallejo, D. de la Iglesia, L. Uribarri, I. Baston, R. Ferreiro, A. Lorenzo, J.E. Dominguez-Muñoz, University Hospital Santiago de Compostela, Gastroenterology, Santiago, Spain
Mucosal healing has become a common endpoint in most therapeutic trials and an important objective that we try to assess in ulcerative colitis (UC) patients. Despite there being important differences between endoscopic Mayo sub-scores of 0 and 1, most important trials consider both as mucosal healing. We hypothesised that only an endoscopic Mayo score of 0 should be defined as mucosal healing. The aim of this study is to evaluate the difference between endoscopic Mayo-0 and Mayo-1 in the clinical course of UC.
A prospective observational cohort study was designed. All UC patients who presented mucosal healing in a colonoscopy were consecutively included and classified according to the Montreal Classification. Mucosal healing was defined as an endoscopic Mayo sub-score of 0 or 1. In order to avoid interpretation bias, all colonoscopies were performed and scored by the same endoscopist. Mayo-0 was defined as normal or inactive disease and Mayo-1 as presence of erythema, decreased vascular pattern or mild friability. Clinical relapse was defined as the need for remission induction treatment, any treatment escalation, hospitalisation or colectomy. In order to assess the clinical course of UC, all clinical relapses were evaluated at months 6 and 12. The influence of demographic variables in the different Mayo subgroups in the clinical course was also evaluated. Results are shown as odds ratio (OR) and 95CI and analyzed by the chi-squared test and multiple regression whenever appropriate.
187 consecutive UC patients with mucosal healing [127 (67.9%) Mayo-0 and 60 (32.1%) Mayo-1] were included [94 male (50.3%), mean age 52 years, ages ranging from 22 to 85]. UC was classified as E1 in 31.3% of patients, E2 in 42.2%, and E3 in 26.5% according to the Montreal classification. 9.4% of patients with Mayo-0 and 36.6% with Mayo-1 presented a relapse during the first 6 months of follow-up (p < 0.001). These differences in relapses were independent of the UC extension (E1 p = 0.006, E2 p = 0.002, E3 p = 0.008). During the following 6 months (from 6 to 12 month) the number of patients who relapsed was similar in Mayo 0 and 1 scores (14.6%vs 16.6%, p = 0.868), probably influenced by the therapy escalation in those who relapsed in the previous 6 months. The only factor independently associated with relapses in a multivariate analysis was a Mayo-1 endoscopic sub-score (OR = 6.27, 95% CI 2.75–14.30, p < 0.001).
Patients with Mayo sub-score 1 presented a worse clinical course than those with Mayo sub-score 0, regardless of the extension of UC. This study demonstrated that mucosal healing should only be considered for patients with an endoscopic Mayo score of 0.