P184. Mucosal healing does not correspond to histological healing in ulcerative colitis
L. Laterza1, I. Scoleri1, S. Bibbò1, E. Gaetani1, G. Bruno1, L. Larosa2, A. Poscia3, A. Amato4, L.M. Minordi2, L. Bonomo2, G. Cammarota1, A. Gasbarrini1, V. Gerardi1, 1Gastroenterology Division, Catholic University of the Sacred Hearth, Rome, Italy, 2Radiology Department, Catholic University of the Sacred Hearth, Rome, Italy, 3Institute of Hygiene, Catholic University of the Sacred Hearth, Rome, Italy, 4Institute of Anestesiology, Catholic University of the Sacred Hearth, Rome, Italy
Ulcerative colitis (UC) is a chronic inflammatory disease limited to the large bowel mucosa, thus mucosal healing (MH) assessed by endoscopy could be a potential target in the treatment of these patients. In fact, MH demonstrated to modify the natural history of the disease, reducing the need for surgery and the risk of colorectal cancer. MH lowers the risk of disease reactivation, but some patients relapse in spite of the presence of MH. It is reasonable to think that the microscopic disease activity beyond MH could explain these cases. Our aim is to assess how many patients with MH have a microscopic disease activity and what kind of lesions are the most frequent in these cases.
We used Mayo endoscopic score to assess endoscopic activity. 28 patients with MH defined as Mayo score=0 were enrolled. For each patient microscopic disease activity has been evaluated by an expert pathologist based on the presence of acute or chronic inflammatory cell infiltrate, basal plasmacytosis, basal lymphoid aggregates, stromal changes, lamina propria eosinophils, crypt branching, crypt distortion, crypt atrophy/depletion, cryptitis, crypt abscesses, surface irregularity, mucin depletion, erosions and Paneth cell metaplasia.
No patients showed absence of histological lesions, whereas in all patients a chronic inflammatory infiltrate persisted. In 60.71% of cases an acute inflammatory infiltrate could be demonstrated. 42.86% of patients showed basal lymphoid aggregates, 25% mucin depletion, 21.43% basal plasmacytosis and 17.86% lamina propria eosinophils. 21.43% of patients had cryptitis, 14.29% crypt distortion and Paneth cell metaplasia. Erosions and crypt atrophy/depletion were present in 10.71% and 7.14% of cases, respectively. Only 3.57% of patients had crypt abscesses. No patients showed surface irregularity, stromal changes or crypt branching.
A microscopic disease activity persists in all patients with MH, thus the endoscopic remission does not correlate with histological healing. Further studies are required to assess if persistent histological lesions could predict clinical relapse.