Amyloidosis occurs when abnormal antibody proteins or other protein fragments build up in an organ. As the protein accumulates, organ function begins to decline. Amyloidosis can affect any organ. In its primary form, it is a serious but rare condition: only eight out of every million Americans are diagnosed every year. Its cause is unknown.Amyloid Antibodies and Bone Marrow
The proteins that accumulate in organs are called amyloid proteins. In some cases, the amyloid proteins are abnormal antibodies produced by the bone marrow. Normal antibodies circulate in the blood and break down over time. Amyloid antibodies do not break down as easily. Instead, the antibodies accumulate in the bloodstream. The abnormal antibodies eventually leave the blood and are deposited in organs.
Amyloidosis Can Affect Any Organ
Amyloid deposits can build up in any organ in the body. The disease may affect a single organ, or it may be systemic, affecting organs throughout the body. The following areas of the body appear to be more susceptible to amyloid accumulation than others:
Protein Build-up and Disease
Although the cause of amyloidosis is a mystery, we know that it can be inherited. The condition has also been linked to long-term kidney dialysis and other specific diseases.
Abnormal plasma cells are responsible for the excessive protein production in some forms of amyloidosis, as well as in other diseases such as multiple myeloma, a type of bone marrow cancer.
Amyloid deposits have been found in the brains of patients with Alzheimer’s, the leading cause of dementia in the United States. Protein deposits in the brain are also associated with Creutzfeldt-Jakob disease and mad cow disease (bovine spongiform encephalopathy). Creutzfeldt-Jakob disease is a rapidly progressing brain disease characterized by prion protein build-up. Mad cow disease is a similar disorder that affects cattle and sheep. Eating meat contaminated with mad cow disease increases the chances of developing Creutzfeldt-Jakob disease.
If excessive proteins are deposited in the pancreas, type 2 diabetes may result due to an impaired production of insulin.
Prognosis, Symptoms, and Survival Rates
Amyloidosis symptoms and prognosis depend heavily on the organ affected by amyloid deposits. Amyloidosis of the brain, for instance, may result in dementia, while cardiac difficulties may develop if deposits build up in the heart. A gradual loss of kidney function due to amyloid build-up may lead to kidney failure.
Survival rates vary from a few months to several decades, depending on the area of the body affected and the type of amyloidosis diagnosed.