Amyloidosis is a group of related diseases in which a protein called amyloid builds up in one or many organs — typically the kidney, heart, central nervous system (CNS), and/or liver — and interferes with organ function, eventually leading to organ failure.
Each year, 3,000 cases of the disease are diagnosed in the United States. Symptoms include fatigue, weight loss, and — depending on the organs involved — may also include a feeling of fullness (liver), numbness and tingling in the lower extremities (CNS), shortness of breath and dizziness on standing (heart), and fluid accumulation in the legs (kidney).
Amyloidosis is classified on the basis of the precursor proteins involved (amyloid is a protein conformation disorder). Treatment is usually aimed at eliminating the source of the abnormal precursor protein.
- Primary amyloidosis (AL, amyloid light chain) is associated with a clonal plasma cell disease and the immunoglobulin light chains made by the abnormal plasma cells. AL also occurs in amyloidosis associated with multiple myeloma. Treatment involves chemotherapy or stem cell transplantation to eliminate the plasma cells (the source of the abnormal light chains).
- Familial amyloidosis (AF) is associated with a genetic abnormality that can be inherited. AF causes the liver to make an abnormal form of a protein called transthyretin. The treatment for AF is liver transplantation.
- Secondary amyloidosis (AA) is associated with inflammation and elevated levels of serum amyloid A caused by inflammation. Treatment involves elimination of the source of inflammation.