How to Test for Paraprotein?

A paraprotein can be detected in the blood using tests called Serum Protein Electrophoresis and Serum Free Light Chains. These will detect slightly different kinds of paraproteins (“Intact Paraprotein” or “Light Chain”), but they are both produced by the same process and are usually managed the same way.

What is paraprotein in your blood?

A paraprotein is a monoclonal immunoglobulin or immunoglobulin light chain (Bence Jones protein) present in the blood or urine and arising from clonal proliferation of mature B‐cells, most commonly plasma cells or B‐lymphocytes. Alternative terms include monoclonal protein or M‐band.

What investigations would be performed if a paraprotein was identified?

Serum and/or urine immunofixation is conducted to confirm the presence of the paraprotein as well as to determine the isotype of the paraprotein. A serum light chain assay is conducted or recommended to the ordering clinician.