Ulcerative colitis [UC] is a chronic inflammatory bowel disease [IBD] characterised by colonic inflammation extending to a variable extent from the rectum. Care of the patient with UC requires appropriate input from across the multiprofessional team. These guidelines summarise the recommended medical treatment for adults with UC. Other ECCO guidelines consider the approach to UC diagnosis and monitoring,^1–3 nursing care,⁴ management of disease complications,^5–7 risk of infection,⁸ and technical aspects of surgery.⁹ This document was prepared as part of a process that also led to the publication of a related guideline with recommendations on the surgical care of the patients with UC and on the medical aspects of the management of the patient hospitalised with severe UC. ECCO Guidelines on Therapeutics in Ulcerative Colitis: Surgical Treatment.

This article is the second in a series of two publications relating to the European Crohn’s and Colitis Organisation [ECCO] evidence-based consensus on the management of Crohn’s disease. The first article covers medical management; the present article addresses surgical management, including preoperative aspects and drug management before surgery. It also provides technical advice for a variety of common clinical situations. Both articles together represent the evidence-based recommendations of the ECCO for Crohn’s disease and an update of previous guidelines.

This is the second of a series of two articles reporting the European Crohn’s and Colitis Organisation [ECCO] evidence-based consensus on the management of adult patients with ulcerative colitis [UC]. The first article is focused on medical management, and the present article addresses medical treatment of acute severe ulcerative colitis [ASUC] and surgical management of medically refractory UC patients, including preoperative optimisation, surgical strategies, and technical issues. The article provides advice for a variety of common clinical and surgical conditions. Together, the articles represent an update of the evidence-based recommendations of the ECCO for UC.

Background & Aims: CD11b⁺Gr-1⁺ myeloid-derived suppressor cells (MDSCs) have been shown to cause T-cell tolerance in tumor-bearing mice; however, little is known about the role of MDSCs in chronic inflammation. Here, for the first time, we have identified and analyzed their role in inflammatory bowel disease (IBD). Methods: Repetitive adoptive transfer of clone 4/T-cell receptor (CL4-TCR) transgenic CD8⁺ T cells into VILLIN-hemagglutinin (HA) transgenic mice was performed on days 1, 12, and 27. Recipient mice were analyzed for immunopathology, HA-specific CD8⁺ T-cell responses, and CD11b⁺Gr-1⁺ MDSCs (frequency, phenotype, expression analysis, and in vitro as well as in vivo function). In addition, peripheral blood from patients with active Crohn's disease and ulcerative colitis was examined for the presence and function of human MDSCs denoted as CD14⁺HLA-DR^−/low cells. Results: Repetitive transfer of HA-specific CD8⁺ T cells prevented VILLIN-HA recipient mice from development of severe enterocolitis, which is seen after a single transfer of T cells. Repeated transfer of antigen-specific T cells led to an increase in the frequency of nitric oxide synthase 2 and arginase-expressing CD11b⁺Gr-1⁺ MDSCs in spleen and intestine of VILLIN-HA mice with immunosuppressive function. Cotransfer of MDSCs with HA-specific CD8⁺ T cells into naive VILLIN-HA mice ameliorated enterocolitis, indicating a direct immune regulatory effect of MDSCs on induction of IBD by antigen-specific T cells. Finally, an increase in the frequency of human MDSCs with suppressor function was observed in peripheral blood from patients with IBD. Conclusions: These results identify MDSCs as a new immune regulatory pathway in IBD.