Targeting Mucosal Healing in Crohn's Disease.

The goals of medical treatment for Crohn's disease are to induce remission and prevent long-term complications. The assessment of disease activity and response to therapy has moved beyond symptom-based measures to more objective ones, including mucosal healing. Studies of medical therapies target mucosal healing, or more accurately endoscopic remission, as an important treatment outcome. Mucosal healing leads to higher rates of sustained clinical remission and lower rates of hospitalization and disease-related surgery. Although an important goal, treating to the endpoint of mucosal healing has significant limitations. Studies validating mucosal healing are largely based on ileocolonoscopy, which is invasive and limits visualization to the colon and terminal ileum. Other tests, such as capsule endoscopy, noninvasive radiographic imaging, and serum and stool biomarkers, hold promise as alternatives, but more studies are needed. Although patients may demonstrate endoscopic response with optimization of the current medical therapies and the novel therapies under study, many patients do not attain mucosal healing. If there is clinical remission but incomplete mucosal healing after optimization of a therapy, it is not clear whether that therapy should be abandoned. However, despite these limitations, mucosal healing is an important treatment goal for the evaluation of new and existing therapies for Crohn's disease both in clinical studies and in practice.