- A disorder that results from the abnormal deposition of a particular protein, called amyloid, in various tissues of the body. Amyloid protein can be deposited in a localized area, and not be harmful, or in can cause serious changes in virtually any organ of the body. Amyloidosis can occur as an isolated disease or as a result of another illness, including multiple myeloma, chronic infections (such as tuberculosis or osteomyelitis), or chronic inflammatory diseases (such as rheumatoid arthritis and ankylosing spondylitis). The protein that deposits in the brain of patients with Alzheimer's disease is a form of amyloid.
* * *1. A disease characterized by extracellular accumulation of amyloid in various organs and tissues of the body; may be local or generalized; may be primary or secondary. 2. The process of deposition of amyloid protein. [amyloid + G. -osis, condition]- a. of aging characterized by deposition of Congo-red staining material, derived from a variety of proteins, especially in nervous tissue, myocardium and pancreas. Associated with Alzheimer syndrome; intractable congestive heart failure may result.- focal a. SYN: nodular a..- lichenoid a. (lik′en-oyd) localized cutaneous a. with pruritic brownish-red papules, often scaling, most commonly on the lower legs in middle age, due to amyloid infiltration of the papillary dermis. SYN: a. cutis, lichen a.. [G. leichen, lichen, a lichen-like eruption + eidos, resemblance]- light chain-related a. the most common form of primary a. in which the fibrillar amyloid deposits are derived from the amino terminal variable region of the light chains of immunoglobulin; seen in B-lymphocyte and plasma-cell dyscrasias (especially multiple myeloma) and other forms of gammopathy.- macular a. a localized form of a. cutis characterized by pruritic symmetrical brown reticulated macules, especially on the upper back; microscopically, amyloid is deposited as small subepidermal globules.- a. of multiple myeloma foci of a. in mesenchymal tissues of some persons with multiple myeloma; no direct relation between amyloid and Bence Jones protein is conclusively known.- nodular a. a localized form of a. in which amyloid occurs as hard masses or nodules beneath the skin or mucous membranes, e.g., in the larynx, often with local plasma cell infiltration; may be associated with plasma cell dyscrasia or systemic a.. SYN: amyloid tumor, focal a..- primary a. several forms of a. are known, following autosomal dominant [MIM *104750, *105120, *105150, *105200, *105210, *105250] recessive [MIM 204850 and *204900], and X-linked [MIM 301220] inheritance and not associated with other recognized disease. Tends to involve diffusely the arterial walls and mesenchymal tissues in the tongue, lungs, intestinal tract, skin, skeletal muscle, and myocardium, interfering with vital functions; the amyloid frequently does not manifest the usual affinity for Congo red, and sometimes provokes a foreign-body type of inflammatory reaction in the adjacent tissue.- renal a. renal deposits of amyloid, especially in glomerular capillary walls, which may cause albuminuria and the nephrotic syndrome. SYN: amyloid nephrosis (1).- secondary a. a. occurring in association with another chronic inflammatory disease; organs chiefly involved are the liver, spleen, and kidneys, and the adrenal glands less frequently.- senile a. a common form of a. in very old people, usually mild and limited to the heart or seminal vesicles. SEE ALSO: a. of aging.
* * *am·y·loid·o·sis .am-ə-.lȯi-'dō-səs n, pl -o·ses -.sēz a disorder characterized by the deposition of amyloid in organs or tissues of the animal body see PARAMYLOIDOSIS
* * *n.infiltration of the liver, kidneys, spleen, and other tissues with amyloid, a starchlike substance. In primary amyloidosis the disorder arises without any apparent cause; secondary amyloidosis occurs as a late complication of such chronic infections as tuberculosis or leprosy and also in Hodgkin's disease. Amyloidosis is also very common in the genetic disease familial Mediterranean fever (see polyserositis).
* * *am·y·loi·do·sis (am″ə-loi-doґsis) [amyloid- + -osis] a group of conditions of diverse etiologies characterized by the accumulation of insoluble amyloid in various organs and tissues of the body, which compromises vital function. The associated disease states may be inflammatory, hereditary, or neoplastic, and the deposition can be local or generalized (systemic). The most widely used classification is based on the chemistry of the amyloid fibrils.
Amyloidosis. (A), Apple-green birefringence of deposits under polarized light (Congo red). (B), Fluorescence of deposits under ultraviolet light (thioflavine T).
Medical dictionary. 2011.