Myeloma Protein

Myeloma Protein is usually a monoclonal antibody or immunoglobulin fragment that is produced by malignant myeloma cells, or plasma cells.

Other terms for this protein is M-protein, spike protein,or paraprotein. This proliferation of the myeloma protein has several deleterious effects on the body, including impaired immune function, abnormally high viscosity ("thickness") of the blood, and kidney damage.

Myeloma is a malignancy of the plasma cell. Plasma cells produce immunoglobulins, which are commonly called antibodies. There are literally thousands of different antibodies, each consisting of pairs of heavy and light chains. Antibodies are typically grouped into five types: IgA, IgD, IgE, IgG, and IgM. When someone contracts myeloma, a malignant clone, a rogue plasma cell, reproduces in an uncontrolled fashion, resulting in overproduction of the specific antibody that it was designed to produce. Each type of antibody has a different number of light chain and heavy chain pairs. As a result, there is a characteristic normal distribution of plasma cells in the blood by molecular weight. When there is a malignant clone, there is usually overproduction of a single antibody, resulting in a "spike" on the normal distribution, which is called an M spike (or monoclonal spike). People will sometimes develop a condition called MGUS (Monoclonal gammopathy of undetermined significance), where there is overproduction of one antibody but the condition is benign (does not threaten the patient's health). An explanation of the difference between multiple myeloma and MGUS can be found in the International Myeloma Foundation's Patient Handbook and Concise Review