Amyloid
Amyloid: Any of a number of complex proteins that are deposited in tissues and that share selected laboratory features such as a change in the fluorescence intensity of certain aromatic dyes like Congo Red.
The deposition of amyloid occurs in a number of diseases. In many of these, there is disagreement as to whether amyloid causes the disease or is simply a sign of the disease downstream from the cause. (In Alzheimer’s disease, those who believe that the deposition of beta-amyloid protein kills neurons are called baptists.)
Amyloid may be deposited widely in the body, as in systemic amyloidosis. Or the deposition of amyloid may be organ-specific and limited, for instance, to the pancreas, as in type 2 diabetes, or the central nervous system, as in Alzheimer’s disease, Parkinson’s disease, Huntington disease, Creutzfeldt-Jakob disease and bovine spongiform encephalopathy (mad cow disease).
The term amyloid comes from amylo- (starch) + -oid (like) = like starch. This reflects the mistaken identification of the substance as starch based on crude staining techniques.
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A group of diseases that result from the abnormal deposition of a protein, called amyloid, in various tissues of the body. Amyloid protein can be deposited in a localized area, and it may not be harmful or it may affect only a single tissue of the body. This form of amyloidosis is called localized amyloidosis. […]
- Amyloidosis, primary
A disorder of plasma cells (special white blood cells that produce antibodies), this is one of a group of diseases (called amyloidosis) in which protein deposits (amyloid) accumulate in one or more organ systems in the body. Primary amyloidosis is the most common type of amyloidosis in many countries including the U.S. The protein deposits […]
- Amyloidosis, hereditary
A familial (inherited) disorder in which protein deposits (amyloid) accumulate in one or more organ systems in the body. Hereditary amyloidosis is a relatively uncommon cause of amyloidosis. The more common forms of amyloidosis are primary an secondary amyloidosis. However, hereditary amyloidosis is found worldwide. It occurs in families of nearly every ethnic background. The […]
- Amyloidosis, secondary
One of a group of diseases (called amyloidosis) in which protein deposits (amyloid) accumulate in one or more organ systems in the body, secondary amyloid is caused by a chronic infection or inflammatory disease such as rheumatoid arthritis, familial Mediterranean fever, osteomyelitis, or granulomatous ileitis. The protein deposits in this type of the disease are […]
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ALS usually leads to death within 5 years of the time the diagnosis of ALS is made; the range is from 2 to 7 years.