A
myeloma protein is an abnormal
immunoglobulin fragment or
immunoglobulin light chain that is produced in excess by an abnormal
clonal proliferation of
plasma cells, typically in
multiple myeloma. Other terms for such a protein are
M protein,
M component,
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.