Is mucosal healing more common than clinical remission in ulcerative colitis? – Is it the truth or only a myth coming from the studies?

Background. The most important goals of the recent therapies of ulcerative colitis (UC) are to induce and maintain clinical remission and to achieve mucosal healing (MH). Rate of endoscopic remission has been shown to be higher than that of clinical remission in large trials like ULTRA and PURSUIT. The aim of our study was to evaluate the correlation between clinical and endoscopic disease activities of UC defined by activity scores. Methods. Clinical and endoscopic activities were evaluated in 100 consecutive UC patients. Clinical activities were defined by two activity indices: the Rachmilewitz Activity Index (CAI) and the partial Mayo score. Colonoscopies and patient enrolments were performed by 2 experienced gastroenterologists and endoscopists. They graded the findings both according to the endoscopic part of the Rachmilewitz Activity Index (EI) and the Mayo endoscopic subscore. Mucosal healing was defined as Mayo endoscopic subscore and EI of 0. Histological activity was scored by Riley score. Results. Clinical and endoscopic activities showed strong correlations using both scoring systems (p=0.0029 and p=0.0001). Endoscopic disease activity also correlated with the histological activity (p≥0.001). Significant correlation was shown between the clinical activity and MH (p=0.0012 and p≥0.001). No association was showed with the extension of the disease and clinical or endoscopic activity. Conclusion. Assessment of MH is very important for guiding therapy and for evaluation of remission in patients with UC. Our result showed good correlation between the clinical, endoscopic and histological activities of UC focusing on the importance of evaluating the endoscopic activity of the patients