Serum electrophoresis is essential in the investigation of suspected paraproteinaemia and immune deficiency. Characteristic patterns are also seen in the presence of an acute phase response, nephrotic syndrome, alpha 1 antitrypsin deficiency, inflammatory and infective disorders. SPE is performed on all specimens submitted for immunoglobulin quantitation to check whether the immunoglobulins are polyclonal or monoclonal proteins. Polyclonal increases are due to and increased activity of numerous different lymphocytes and are associated with a wide range of infectious and inflammatory diseases including liver disease. The main value in serum electrophoresis is detection of monoclonal immunoglobulins associated with lymphoid malignancy; myeloma or related haematological disorders. Since quantitaive immunoglobulin measurements cannot differentiate between monoclonal and polyclonal immunoglobulins, paraprotein determination (monoclonal protein) must be carried out by quantitation of bands obtained on electrophoresis.
Suspected myeloma and related B cell disease, immunodeficiency.
Quantitation of myeloma.
The level and class of paraprotein have diagnostic and prognostic indications. Average serum concentration (g/L) in myeloma at presentation is IgG 43;IgA 28; IgM 19; IgD 14. The class and concentration re often prognostic (IgA or higher value of any class is poor) IgM in Waldenstroms is usually above 30. In MGUS levels are often below 10g/L. Light chain paraproteins are also detected during electrophoresis. High levels of paraprotein can lead to hyperviscosity syndromes.Note that some paraproteins particularly IgMk can have autoantibody activity and be biologically active at relatively low concentrations (e.g monoclonal rheumoatoid factors or cold agglutinins).
Serum Separator Tube (SST)
Capilliary Zone Electrophoresis (CZE) and Immunofixation of monoclonal proteins.
No restrictions unless cryoglobulinaemia is suspected.
Qualitative description of electrophoretic pattern given (monoclonal, polyclonal, acute phase pattern etc). Paraprotein class of immunoglobulin given any monoclonal protein will be measured by densitometry.
Assay range notes
Quantitation 3-100g/L. Lower values detectable but cannot be quantified.
5 – 7 days
Immunology The James Cook University Hospital