Extracellular deposition of protein as insoluble fibrils resulting in organ dysfunction. Many chronic inflammatory processes or infections can cause secondary amyloidosis (Amyloid A amyloidosis, systemic AA amyloidosis) due to deposition of a proteolytic fragment of serum amyloid A protein (SAA). The condition while rare is a feared complication of rheumatoid arthritis at up to 5% of patients after 20 years as treatments remain experimental and survival from onset is often only a few years. Survival can be related to serum SAA concentration. Staining with congo red is used to identify the amyloid.
Various forms of primary amylodosis exist such as:
- Familial mediterranean fever.
- Primary systemic (amyloid light-chain, or AL) amyloidosis
- ↑ Husby G. Treatment of amyloidosis and the rheumatologist. State of the art and perspectives for the future. Scandinavian journal of rheumatology 1998;27(3):161-5.
- ↑ Lachmann HJ, Goodman HJ, Gilbertson JA, Gallimore JR, Sabin CA, Gillmore JD, et al. Natural History and Outcome in Systemic AA Amyloidosis. N Engl J Med 2007;356(23):2361-2371. (Direct link – subscription may be required.)