M components and cancer.

Intention of this study was to prove or exclude in patients with different neoplasms some M components which can escape routine electrophoretic analysis or immunoelectrophoretic analysis with polyvalent antiserum. All serum samples from 606 patients were investigated also with monospecific antisera against heavy chains--alpha, gamma, mu and delta--and in suspicion of abnormality also with antisera against light chains. Patterns similar to those found in cases of heavy chain diseases were absent in all patients. M components of IgD class were not found, as well. As to M components of usual types a relatively high incidence was found in lymphoproliferative malignancies excluded myelomas or Waldenstroöm's macroglobulinemias (5.61% in adults and 2.32% in children). On the basis of results the importance of immunoelectrophoretical analysis with monospecific antisera in all these cases is pointed out; not only in attempt to discover additional subjects of heavy chain diseases but also to detect mild "macroglobulinemic" abnormalities which may not be so far detected on electrophoretical pattern.