Lymphocytic insulitis in a juvenile dog with diabetes mellitus.
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.
Jouvion
G
G
UMR 703 INRA-ENVN, Department of Pathology, National Veterinary School of Nantes, France.
Abadie
J
J
Bach
J M
JM
Roux
F
F
Miclard
J
J
Deschamps
J Y
JY
Guigand
L
L
Saï
P
P
Wyers
M
M
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