Monoclonal gammopathy in general practice. Diagnostic value of typing and quantitation of immunoglobulins.

Abstract

The diagnostic value of typing and quantitation of immunoglobulins were investigated in 88 persons with monoclonal gammopathy diagnosed in general practice. Of the 88 persons, 13 had malignant monoclonal gammopathy (MMG) and 75 monoclonal gammopathy of undetermined significance (MGUS). IgG was the immunoglobulin most often associated with a benign disorder. The higher the concentration of M-component was, the higher too was the frequency of MMG. All 40 persons with normal levels of immunoglobulins had MGUS. Suppression of immunoglobulins other than the M-component was found in 69% with MMG and 20% with MGUS. The combination of an elevated level of monoclonal immunoglobulin and suppression of other immunoglobulins was seen in 69% with MMG, but in only 12% with MGUS. The results from typing and quantitating may serve to indicate whether further investigations are justified in patients not suspected of MMG, but in whom a M-component is found.