Plasma cells syntheses and assembles immunoglobulin from two heavy and two light chains thus producing 5 types (IgG, IgA, IgM, IgD and IgE) and this can be further types as being kappa or lambda based on the light chain.
Monoclonal gammopathies: A disease state associated with a single plasma cell producing elevated levels of an immunoglobulin of a single class and type, known as monoclonal proteins, M-proteins or paraproteins. These can be of a benign nature or of uncertain significance and in some cases, indicate a malignancy, such as multiple myeloma or Waldenström’s macroglobulinaemia. These must be differentiated from polyclonal gammopathies seen as secondary due to clinical disorders such as chronic liver disease, collagen disorders, rheumatoid arthritis and chronic infection. These abnormal plasma proteins are filtered by kidney and appear in the urine thus providing valuable insight not only into the type of protein but also the renal function.
These can be easily seen as abnormal electrophoretic pattern. A suggested work-up for full characterisation includes measuerement of IgG, IgA, IgM, IgD; B2M; albumin, total protein, densitometry (paraprotein quantitation), cryoglobulin; viscosity; immunofixation; Kappa and Lambda light chains and Creatinine.
Initially B-cell abnormalities can be visualised by electrophoresis, this will show elevated levels of protein with different mobilities. In this example, the immunoglobulin abnormalitites is seen as a band in the far left-hand side track (for comparison see the track on the near-left which is normal (included for reference purposes)). The abnormal band will require further investigation to determine the type of immunoglobulin present.