Page 1250 - Veterinary Immunology, 10th Edition

VetBooks.ir Chronic Active Hepatitis

Doberman Pinschers may develop an autoimmune hepatitis. The
symptoms are typical of liver disease with anorexia, depression,

weight loss, diarrhea, polydipsia, polyuria, icterus, and eventually
ascites. The disease commonly presents between 3 and 6 years of
age but may have been present subclinically for many years. On
necropsy, there is intense inflammation and scar tissue formation
around small hepatic veins in the liver. The lesions contain

lymphocytes, plasma cells, and macrophages. The disease
eventually causes progressive fibrosis and destruction of
hepatocytes. About half of affected dogs develop antibodies to

hepatocyte cell membranes. These antibody-positive dogs have
more severe disease than dogs without antibodies. In addition,
lymphocytes from about 75% of affected dogs respond to liver
membrane proteins in vitro. Hepatocytes from affected dogs, but
not from normal dogs, express MHC class II antigens. This MHC

expression correlates with the severity of the disease, whereas
corticosteroid treatment reduced both MHC expression and disease
severity. It has been suggested therefore that the disease results

from a cell-mediated attack on abnormally expressed MHC
molecules or an antigen associated with them.

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