REVIEW ARTICLEHistological Remission in Ulcerative Colitis Under the Microscope Is the CureChateau, Thomas MD1,2; Feakins, Roger MD3; Marchal-Bressenot, Aude MD, PhD4; Magro, Fernando MD, PhD5,6,7; Danese, Silvio MD, PhD8; Peyrin-Biroulet, Laurent MD, PhD2Author Information 1Department of Hepato-Gastroenterology, University Hospital of Grenoble, University of Grenoble Alpes, Grenoble, France; 2Department of Hepato-Gastroenterology and Inserm U954, University Hospital of Nancy, University of Lorraine, Vandoeuvre-lès-Nancy, France; 3Department of Cellular Pathology, Royal Free Hospital, London, United Kingdom; 4Department of Pathology, University Hospital of Reims, Reims, France; 5Department of Gastroenterology, Hospital São João, Porto, Portugal; 6Department of Biomedicine, Unit of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto, Porto, Portugal; 7MedInUP, Center for Drug Discovery and Innovative Medicines, Porto, Portugal; 8IBD Center, Humanitas Clinical and Research Center, Milan, Italy. Correspondence: Laurent Peyrin-Biroulet, MD, PhD. E-mail: firstname.lastname@example.org. SUPPLEMENTARY MATERIAL accompanies this paper at http://links.lww.com/AJG/B310, http://links.lww.com/AJG/B309, http://links.lww.com/AJG/B311, http://links.lww.com/AJG/B312, http://links.lww.com/AJG/B313 Received July 01, 2019 Accepted September 18, 2019 Online date: December 5, 2019 The American Journal of Gastroenterology: February 2020 - Volume 115 - Issue 2 - p 179-189 doi: 10.14309/ajg.0000000000000437 Buy SDC Metrics Abstract In recent years, the therapeutic goals in ulcerative colitis (UC) have become increasingly stringent. Histological features seem to be a reliable predictor of disease outcomes after therapy, and histological remission (HR) is the new frontier in the treatment of UC. Here, we first provide a historical perspective before reviewing indexes in the era of biologics; histology as a treatment goal in UC trials; the poor correlation between symptoms, endoscopy, and histology; and the impact of histology on disease outcomes. HR seems to be a promising end point for the treatment of UC because it is typically associated with better outcomes. Two new validated indexes are available to assess histology more accurately in trials, and they may also be applicable to clinical practice. Additional interventional trials are now necessary to establish definitions of HR and its potential for disease modification. © The American College of Gastroenterology 2020. All Rights Reserved.