Metabolic turn over of amyloid fibrils and post-treatment regression of amyloid deposits in systemic amyloidosis with polyneuropathy

Abstract

Systemic amyloidosis that includes familial transthyretin (TTR)-related amyloid polyneuropathy (FAP) and primary systemic immunoglobulin light chain (AL)-derived amyloidosis was long considered to be an incurable disease, but effective therapeutic approaches developed during 20 years ago: liver transplantation for FAP and high dose melphalan with autologous peripheral blood stem cell transplantation (Auto-PBSCT). Systemic amyloidosis is characterized by the presence of an amyloid precursor protein in serum and both treatments can cease the production of amyloid precursor proteins in serum. After transplantation the progression of FAP symptoms certainly stopped, and the patients who were in an early stage of the disease and underwent successful operation showed considerable improvement in their quality of life. Similar clinical recovery was seen in primary systemic AL amyloidosis patients with polyneuropathy after high dose melphalan with auto-PBSCT. Histopathological regression of amyloid deposits on aspirated abdominal fat tissues and/or gastroduodenal mucosa was demonstrated in the patients with long post-treatment courses, indicating that an amyloid precursor protein is dynamically turned over in the lesions with amyloid deposits.