Page 213 - Veterinary Immunology, 10th Edition

VetBooks.ir

FIG. 7.12 The pathogenesis of reactive amyloid fibril deposition.
Misfolded proteins aggregate to form insoluble fibrils.

Multiple myelomas are plasma cell tumors that secrete

antibodies, especially antibody light chains (Chapter 15). Huge
quantities of antibody light chains and their fragments are
produced, and their misfolding results in the deposition of

immunogenic amyloid in organs. Immunogenic amyloid is the most
common form of amyloid in humans, but is very rare in domestic
animals.
Several other forms of localized amyloidosis are recognized in
domestic animals; for example, old dogs may suffer from vascular

amyloidosis, in which amyloid is deposited in the media of
leptomeningeal and cortical arteries. An inherited form of amyloid
has been described in Abyssinian cats. Tumor-like amyloid nodules
and subcutaneous amyloid have been reported in horses, but in

general, amyloid deposits are found in the liver, spleen, and
kidneys, particularly within glomeruli. In humans, amyloid fibrils

213