Daniel Jean, DVM, DACVIM (LA), PhD: No financial relationships to disclose
Presentation Description / Summary: Equine Inflammatory Bowel Disease (IBD) is an immune-mediated condition characterized by mucosal and submucosal infiltration with various immune cells causing a clinical dysfunction of the gastrointestinal (GI) tract, often resulting in malabsorption, weight loss, colic, and diarrhea. The type of infiltrates will steer its classification into lymphoplasmacytic, eosinophilic, histiocytic, neutrophilic and/or granulomatous enteritis/colitis. Various players of the mucosal immune system are proposed to be implicated in the pathogenesis; namely intestinal epithelial cells, innate lymphoid cells, cells of the innate (macrophages/monocytes, neutrophils, and dendritic cells) and adaptative (T-cells and B-cells) immune system, and their secreted mediators (cytokines and chemokines). There is limited knowledge on the interactions between the different players in equine IBD, and most information is extrapolated from human/small animal IBD data. IBD can be diagnosed with the aid of concurrent appropriate clinical signs, blood work, transabdominal ultrasonography, absorption tests, and GI biopsies that can confirm the presence of infiltration and the type of infiltrate. Standardizing protocols and histological criteria could improve the diagnostic value of digestive biopsies, strengthening the tools available to clinicians and pathologists. Treatment of IBD will be a combination of immunosuppressive medications such as glucocorticoids, anthelmintics, dietary modifications, and sometimes surgery. The efficacy of treatment remains unknown. The prognosis remains variable, depending on severity and extend of the disease as well as the initial response to treatment. A comprehensive understanding of the immunologic mechanisms underlying these clinical manifestations will be of central importance for the development of therapies targeting effectively IBD in equine patients.
Learning Objectives:
to improve the understanding the role of the different immune cells in the pathophysiology of IBD in horses.
to differentiate the resident cell population from significant inflammatory infiltrates is challenging, and how to improve the understanding of histological Interpretation.
to have a more finetuned characterization and quantification of immune cells in the intestines and how these informations will help the clinician in the therapeutic/preventive management of the patient and may even provide a prognostic factor.