Definition and evaluation of mucosal healing in clinical practice.

Since the introduction of biological therapy, endoscopic and histological remission, i.e. mucosal healing, has become an important therapeutic goal in Crohn's Disease and Ulcerative Colitis. Mucosal healing is associated with lower rates of hospitalization and surgery, although its role in preventing progression and changing the natural history of the disease has not been clearly demonstrated. A precise definition of mucosal healing has not yet been established, although the concept used in clinical trials is the "complete absence of all inflammatory and ulcerative lesions in all segments of gut" at endoscopy. This definition does not include mucosal improvement and does not distinguish among grades of mucosal healing. In both Crohn's Disease and Ulcerative Colitis trials, several qualitative and quantitative numeric endoscopic indices have been proposed to measure and distinguish endoscopic changes. In addition, the microscopic features associated with inflammatory bowel diseases are considerably modified by the course of the disease and the treatments adopted. However, it is not yet clear whether microscopic healing should be a primary endpoint in clinical trials. In this paper we discuss endoscopic and histological findings and the limitations of the endoscopic and histological indices as a basis for a standardised diagnosis of mucosal healing.

NCX-1015, a nitric-oxide derivative of prednisolone, enhances regulatory T cells in the lamina propria and protects against 2,4,6-trinitrobenzene sulfonic acid-induced colitis in mice.

NCX-1015 is a nitric oxide (NO)-releasing derivative of prednisolone. In this study we show NCX-1015 protects mice against the S. A. development and induces healing of T helper cell type 1-mediated experimental colitis induced by intrarectal administration of 2,4,6-trinitrobenzene sulfonic acid (TNBS). The beneficial effect of NCX-1015 was reflected in increased survival rates, improvement of macroscopic and histologic scores, a decrease in the mucosal content of T helper cell type 1 cytokines (protein and mRNA), and diminished myeloperoxidase activity in the colon. In contrast to its NO derivative, only very high doses of prednisolone were effective in reproducing these beneficial effects. NCX-1015 was 10- to 20-fold more potent than the parent compound in inhibiting IFN-gamma secretion by lamina propria mononuclear cells. Protection against developing colitis correlated with inhibition of nuclear translocation of p65Rel A in these cells. In vivo treatment with NCX-1015 potently stimulated IL-10 production, suggesting that the NO steroid induces a regulatory subset of T cells that negatively modulates intestinal inflammation.