Life Science Encyclopedia

Paraproteinemia (also known as "monoclonal gammopathy") is the presence of excessive amounts of a single monoclonal gammaglobulin (in this case denominated "paraprotein") in the blood. It denotes an underlying immunoproliferative disorder.

Types

Paraproteinaemias may be categorised according to the type of monoclonal protein found in blood:

• Light chains ("Bence Jones protein") only;
• Heavy chains only;
• Whole immunoglobulins (albeit often with an abnormal light / heavy chain ratio). In this case, the paraprotein goes under the name of "M-protein" ("M" for monoclonal). If immunoglobulins tend to precipitate within blood vessels with cold, that phenomenon takes the name of cryoglobulinaemia.

Possible causes

• Leukaemias and lymphomas of various types.
• Myeloma
• Waldenström macroglobulinemia (IgM only)
• Amyloidosis (either light or heavy chains only)

If no cause is identified, the term "monoclonal gammopathy of undetermined significance" is used.