The serum proteome of patients featuring immunoglobulin M (IgM) gammopathy and diagnosed as having IgM multiple myeloma or Waldenstrbm's macroglobulinemia was characterized by differential scanning calorimetry and HevyLite (TM) (HLC) assay. The thermodynamic properties of the thermograms and their deviation from the typical healthy thermogram were found to correlate with the monoclonal protein concentration and the level of the involved (monoclonal) IgM heavy/light chains. Patients monitoring during treatment showed that the variations in the shape of the DSC profiles corresponded to fluctuations of the IgM heavy/light chain levels verifying the two parameters as non-invasive markers for disease progression. (C) 2015 Elsevier B.V. All rights reserved.