title: Lymphocytic insulitis in a juvenile dog with diabetes mellitus.
abstract: Autoimmune diabetes has never been described in a juvenile dog, whereas serological evidence has established its development in adult dogs. Diabetes mellitus was diagnosed in a 3-mo-old Donge de Bordeaux dog suffering from persistent hyperglycemia and concurrent insulinopenia. Histological analysis of the pancreas revealed inflammatory lesions in 40% of the islets of Langerhans, with infiltration predominantly by T lymphocytes (more than 90%), either at the edge (peri-insulitis: 10%) or in the islets (insulitis: 30%). The remaining 60% of the islets showed a marked atrophy due to massive beta cell loss with no loss of alpha cells. This pattern is quite similar to that observed in humans in which a characteristic insulitis containing high numbers of T lymphocytes is found in 20% of the islets at diabetes diagnosis. By contrast, in rodent models, nearly 70% of the islets of Langerhans show inflammation at diagnosis and macrophages and dendritic cells predominate in the inflammatory lesions. This is the first report of lymphocytic insulitis in a juvenile dog exhibiting diabetes mellitus. Our observations suggest an autoimmune origin for the disease in this dog that is similar to human type 1 diabetes mellitus, for which there is no accurate spontaneous large animal model.
authors.affiliation: UMR 703 INRA-ENVN, Department of Pathology, National Veterinary School of Nantes, France.
authors.forename: G
authors.initials: G
authors.lastname: Jouvion
authors.forename: J
authors.initials: J
authors.lastname: Abadie
authors.forename: J M
authors.initials: JM
authors.lastname: Bach
authors.forename: F
authors.initials: F
authors.lastname: Roux
authors.forename: J
authors.initials: J
authors.lastname: Miclard
authors.forename: J Y
authors.initials: JY
authors.lastname: Deschamps
authors.forename: L
authors.initials: L
authors.lastname: Guigand
authors.forename: P
authors.initials: P
authors.lastname: Saï
authors.forename: M
authors.initials: M
authors.lastname: Wyers
mesh_terms: D000818:Animals; D003920:Diabetes Mellitus / Q000473:pathology* / Q000662:veterinary*; D004285:Dogs; D006943:Hyperglycemia / Q000209:etiology; D007150:Immunohistochemistry; D007249:Inflammation / Q000276:immunology / Q000473:pathology; D050417:Insulin-Secreting Cells / Q000473:pathology*; D013601:T-Lymphocytes / Q000276:immunology