[Complex formation between monoclonal IgM and albumin in a patient with macroglobulinaemia (author's transl)].

A remarkable interaction between a monoclonal IgM(x) protein and autologous albumin was found in the serum of a 76 year old male patient (Ke.E) without morphological characteristics of Waldenströms disease. The components were bound noncovalently. Immunoelectrophoretic analysis of 50 additional monoclonal IgM and 10 IgA sera showed a complex formation with albumin in 62% (IgM) and in 90% (IgA). The degree of interaction was, however, less pronounced in comparison with that observed in the serum of Ke.E.