Monoclonal gammapathies

Abstract

A monoclonal gammapathy is characterized by a selective increase of a single serum immunoglobulin due to an only dysregulated clone of B lymphocytes. The laboratory diagnosis of monoclonal immunoglobulins needs a linked serum and urine analysis showing charge and isotype homogeneity. Monoclonal gammapathies are common in the general population and affect about 3% in general population older than age 50. They are a very heterogeneous group of diseases of different etiologies. At presentation about half of them are classified as MGUS (monoclonal gammopathy of undetermined significance) whereas only 30 % have clinically documented plasma cell dyscrasias (multiple myeloma (MM), Waldenstrom’s macroglobulinemia (WM), primary systemic amyloidosis (AL), or a related disorder. Multiple myeloma (MM) is comprised about of 80% monoclonal gammopathies. It is characterized by plasma cells proliferation (>10%) within the bone marrow and an excess of secreted monoclonal immunoglobulins.