MALDI-TOF mass spectrometry can distinguish immunofixation bands of the same isotype as monoclonal or biclonal proteins

Plasma cell disorders (PCDs) are typically characterized by excessive production of a single immunoglobulin, defined as a monoclonal protein (M−protein). Some patients have more than one identifiable M−protein, termed biclonal. Traditional immunofixation electrophoresis (IFE) cannot distinguish if two bands of the same isotype represent biclonal proteins or M−proteins with some other feature. A novel assay using immunoenrichment coupled to...