What Do the Elevated Protein Levels Mean in My Patients with Myeloma, Amyloidosis, and Related Disorders?

Multiple myeloma, light chain amyloidosis, and other plasma cell dyscrasias are characterized, in part, by abnormal production of paraproteins that are often responsible for the sequelae of those diseases. These paraproteins are whole or fragmented immunoglobulins produced by clonal antibody-secreting cells (usually plasma cells, but occasionally, B lymphocytes). Significant heterogeneity exists in the presentation of these diseases, ranging from incidental detection of a monoclonal protein in an asymptomatic patient, to life-threatening manifestations that require urgent diagnostic confirmation and intervention. Successful management of such scenarios requires a fundamental understanding of the laboratory assays at one's disposal, their role in the workup of paraproteinemias, and the interpretation thereof. This review broadly covers these assays and their roles in the diagnosis, prognosis, and management of these diseases.