ABSTRACT
The monoclonal gammopathies are a group of disorders characterized by the proliferation of a single clone of plasma cells that produce a homogeneous monoclonal protein (M protein or myeloma protein) that consists of two heavy polypeptide chains of the same class and subclass and two light polypeptide chains of the same type. The heavy polypeptide chains are gamma (c) in IgG, alpha (a) in IgA, mu (l) in IgM, delta (d) in IgD, and epsilon (e) in IgE. The light-chain types are kappa (j) and lambda (k). It is essential to differentiate between a monoclonal and a polyclonal increase in immunoglobulins, because the former is associated with a clonal process that is malignant or potentially malignant, whereas a polyclonal increase is due to a reactive or inflammatory process.
