Using quantitative immunoprecipitation mass spectrometry (QIP-MS) to identify low level monoclonal proteins

Mass spectrometry has recently been proposed as a novel sensitive screening tool for monoclonal gammopathies. In a small study we have tested the ability of quantitative immunoprecipitation mass spectrometry (QIP-MS) to identify low level monoclonal immunoglobulins not currently detected by the initial serum protein electrophoresis (SPEP) screen. QIP-MS positively identified the primary monoclonal immunoglobulins in all 11 patient samples alongside additional monoclonal immunoglobulins in a subset of patient samples. We conclude that QIP-MS has clinical utility as a first-line screening tool for monoclonal gammopathy investigation, identifying monoclonality in patients with higher sensitivity and resolution compared to the current standard methods.