Amyloidosis

Abstract

Amyloidosis is a generic term for a group of diseases caused by misfolding and extracellular accumulation of certain proteins as fibrillar deposits that stain with Congo red and produce pathognomonic green birefringence when viewed by microscopy under crossed polarised light. The process of amyloid formation and deposition causes progressive organ dysfunction. Amyloidosis is remarkably diverse and can be hereditary or acquired, localised or systemic and lethal or merely an incidental finding. So far, 27 different human proteins with in vivo amyloidogenic potential have been identified of which 15 cause systemic amyloidosis. The classification of amyloid is based on the fibril protein, and different amyloidogenic proteins give rise to distinct but frequently overlapping clinical syndromes. The kidneys are frequently involved in systemic amyloidosis (Table 29.1) which, without treatment, is usually fatal. Current management of amyloidosis is dependent upon determining the fibril protein and reducing its abundance. This can result in regression of amyloid deposits, prevention or recovery of organ failure and improved survival.