Laboratory Analysis for Monoclonal Gammopathies
Monoclonal gammopathy is a disorder caused by proliferation of a single clone of plasma cells. Monoclonal gammopathies may be present in a wide spectrum of diseases that include malignancies of plasma cells or B lymphocytes (eg, multiple myeloma or macroglobulinemia), disorders involving monoclonal proteins of abnormal structure, and apparently benign premalignant conditions. Plasma cells secrete immunoglobulins (antibodies) and each clone of plasma cells produces a single type of immunoglobulin (monoclonal protein). In plasma cell proliferative disorders, there is an expansion of a single plasma cell clone, and the increased concentration of its secreted immunoglobulin can be detected as a monoclonal protein. The presence of a monoclonal immunoglobulin serves as a marker of the clonal proliferation of the plasma cells, and is diagnostic for a monoclonal gammopathy.
Protein electrophoresis and immunofixation electrophoresis of both serum and 24-hour urine have been the standard assays for diagnosis of monoclonal gammopathy. However, Mayo Medical Laboratories now recommends #87997 Monoclonal Protein Study, Expanded Panel, Serum. A Mayo Clinic study has demonstrated that the use of a serum free light chain assay increased the diagnostic sensitivity of serum studies, eliminating the need for urine studies in the screening stage. #87997 Monoclonal Protein Study, Expanded Panel, Serum offers improved detection of monoclonal gammopathies, includes a serum free light chain assay in the initial diagnostic screen, and eliminates the need for a 24-hour urine specimen.