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Overview of Plasma Cell Disorders

(Dysproteinemias; Monoclonal Gammopathy; Paraproteinemias; Plasma Cell Dyscrasias)


James R. Berenson

, MD, Institute for Myeloma and Bone Cancer Research

Last full review/revision Sep 2019| Content last modified Sep 2019
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Plasma cells are present mainly in bone marrow and lymph nodes. Every plasma cell divides repeatedly to form a clone. The cells of a clone produce only one specific type of antibody. Because thousands of different clones exist, the body can produce a vast number of different antibodies to fight the numerous infectious microorganisms to which the body is exposed.

In plasma cell disorders, one clone of plasma cells multiplies uncontrollably. As a result, this clone produces vast amounts of a single antibody (monoclonal antibody) known as the M-protein. In some cases (such as with monoclonal gammopathies), the antibody produced is incomplete, consisting of only light chains or heavy chains (functional antibodies normally consist of two pairs of two different chains called a light chain and heavy chain).

The abnormal plasma cells and the antibodies they produce are limited to one type, and levels of other types of antibodies that help fight infections fall. Thus, people with plasma cell disorders are often at higher risk of infections. The ever-increasing number of abnormal plasma cells also invades and damages various tissues and organs, and the antibody produced by the clone of plasma cells can sometimes damage vital organs, especially the kidneys and bones.

Plasma cell disorders from more common to less common include

These disorders are more common among older people.

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