Vacuolar myopathy in a dog resembling human sporadic inclusion body myositis.
Sporadic inclusion body myositis (sIBM) is the most common myopathy in people over the age of 50 years. While immune-mediated inflammatory myopathies are well documented in dogs, sIBM has not been described. An 11-year-old dog with chronic and progressive neuromuscular dysfunction was evaluated for evidence of sIBM using current pathologic, immunohistochemical and electron microscopic diagnostic criteria. Vacuoles and congophilic intracellular inclusions were identified in cryostat sections of multiple muscle biopsies and immunostained with antibodies against amyloid-beta peptide, amyloid-beta precursor protein, and proteosome 20S of the ubiquitin-proteosome system. Cellular infiltration and increased expression of MHC Class I antigen were observed. Cytoplasmic filamentous inclusions, membranous structures, and myeloid bodies were identified ultrastructurally. These observations constitute the first evidence that both the inflammatory and degenerative features of human sIBM can occur in a non-human species.
King
Jason
J
Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA.
LeCouteur
Richard A
RA
Aleman
Monica
M
Williams
D Colette
DC
Moore
Peter F
PF
Guo
Ling T
LT
Mizisin
Andrew P
AP
Shelton
G Diane
GD
D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D004283:Dog Diseases / Q000473:pathology* / Q000503:physiopathology; D004285:Dogs; D004576:Electromyography / Q000379:methods; D008297:Male; D046529:Microscopy, Electron, Transmission / Q000379:methods; D018482:Muscle, Skeletal / Q000503:physiopathology / Q000648:ultrastructure; D018979:Myositis, Inclusion Body / Q000473:pathology / Q000503:physiopathology / Q000662:veterinary*; D014617:Vacuoles / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure
D015703:Antigens, CD