Overview

Amyloidosis is not cancer, but it is a serious, potentially life-threatening condition that can occur because of some cancers. The basis of amyloidosis is the amyloid, which is an abnormal protein that enters tissues or organs. When enough amyloid proteins are present in an organ to interfere with its functioning and cause symptoms, the condition called amyloidosis results.

Amyloid proteins are made by plasma cells, a type of white blood cell in the bone marrow (the spongy, red tissue in the inner part of the large bones). In normal situations, these plasma cells make antibodies that protect the body from diseases or infection. The antibodies are created, used, and then broken down and recycled by our bodies. However, in amyloidosis, the plasma cells produce antibodies that cannot be broken down. These abnormal proteins leave the bloodstream and eventually enter tissues and organs.

Only in the past few decades have doctors and researchers begun to understand the nature of amyloid proteins and how they can cause damage.

There are different types of amyloidosis, including the following:

AL amyloidosis. This is the most common type of amyloidosis in the United States. The amyloid proteins that accumulate in the tissues in this condition are known as light (L) chains. It is not usually associated with another underlying condition, although it is sometimes associated with multiple myeloma.

AA amyloidosis. In this condition, the amyloid protein that accumulates in the tissues is known as the A protein. AA amyloidosis is associated with chronic diseases, such as diabetes, tuberculosis, rheumatoid arthritis, or inflammatory bowel disease. It may also accompany aging. The spleen, liver, kidneys, adrenal glands, and lymph nodes may be involved.

Hereditary amyloidosis (ATTR). Hereditary amyloidosis is a specific type of amyloidosis that can be passed down from generation to generation in a family. It may cause peripheral sensory and motor neuropathy (problems with the central nervous system), carpal tunnel syndrome, and eye abnormalities. The most common subtypes involve the transthyretin (TTR) protein. Hereditary amyloidosis is rare.

This section covers AL, AA, and hereditary amyloidosis. Other types of amyloidosis include ß2 microglobulin amyloidosis, which occurs in some patients with chronic renal (kidney) problems, and localized forms of amyloidosis.

Statistics

Primary amyloidosis is rare, affecting about 2,000 people per year in the United States. Secondary amyloidosis is more common than primary amyloidosis.

Source: Amyloidosis Foundation

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