Representative patterns of serum electrophoresis. The upper panel illustrates the normal pattern of serum protein on electrophoresis. Since there are many different immunoglobulins in the serum, their differing mobilities in an electric field produce a broad peak. In conditions associated with increases in polyclonal immunoglobulin, the broad peak is more prominent (middle panel). In monoclonal gammopathies, the predominance of a product of a single cell produces a "church spire" sharp peak, usually in the γ globulin region (bottom panel). The nature of the M component is variable in plasma cell disorders. It may be an intact antibody molecule of any heavy. | Chapter 106. Plasma Cell Disorders Part 2 Figure 106-1 Representative patterns of serum electrophoresis. The upper panel illustrates the normal pattern of serum protein on electrophoresis. Since there are many different immunoglobulins in the serum their differing mobilities in an electric field produce a broad peak. In conditions associated with increases in polyclonal immunoglobulin the broad peak is more prominent middle panel . In monoclonal gammopathies the predominance of a product of a single cell produces a church spire sharp peak usually in the y globulin region bottom panel . The nature of the M component is variable in plasma cell disorders. It may be an intact antibody molecule of any heavy chain subclass or it may be an altered antibody or fragment. Isolated light or heavy chains may be produced. In some plasma cell tumors such as extramedullary or solitary bone plasmacytomas of patients will have an M component. In 20 of myelomas only light chains are produced and in most cases are secreted in the urine as Bence Jones proteins. The frequency of myelomas of a particular heavy chain class is roughly proportional to the serum concentration and therefore IgG myelomas are more common than IgA and IgD myelomas. Multiple Myeloma Definition Multiple myeloma represents a malignant proliferation of plasma cells derived from a single clone. The terms multiple myeloma and myeloma may be used interchangeably. The tumor its products and the host response to it result in a number of organ dysfunctions and symptoms of bone pain or fracture renal failure susceptibility to infection anemia hypercalcemia and occasionally clotting abnormalities neurologic symptoms and manifestations of hyperviscosity. Etiology The cause of myeloma is not known. Myeloma occurred with increased frequency in those exposed to the radiation of nuclear warheads in World War II after a 20-year latency. A variety of chromosomal alterations have been found in patients with myeloma 13q14 deletions
