From arthritis to Alzheimer's disease: current concepts on the pathogenesis of amyloidosis.

Amyloid is a generic term referring to a group of diverse but specific extracellular protein deposits which all have common morphologic properties, staining characteristics, and x-ray diffraction and infrared spectra. This review considers the new classification of amyloids, based on the underlying peptides forming the protein fibril, and their diversity. The pathogenesis of inflammation-associated amyloid and its relationship to high density lipoprotein metabolism is examined in detail. The lessons learned from models of inflammation-associated amyloid are extended to the other amyloids (e.g., Alzheimer's disease), and potential reasons for the common structural properties of all amyloids are explored.