The anion gap and routine serum protein measurements in monoclonal gammopathies.

Background And Objectives: An abnormal anion gap and an increased total protein and globulin are clues to the diagnosis of monoclonal gammopathy. We explored the utility of these markers in IgG, IgA, IgM, and free light chain monoclonal gammopathies.

Design, Setting, Participants, & Measurements: The anion gap, Na(+) - (Cl(-) + HCO(3)(-)), corrected for hypoalbuminemia, was calculated in patients with monoclonal gammopathies.