Idiotype‐bearing Peripheral Blood Lymphocytes in Human Multiple Myeloma and Waldenström's Macroglobulinaemia

Antisera raised against idiotypic determinants (ID) of myeloma proteins and macroglobulins have been used to differentiate peripheral blood lymphocyte (PBL) populations from individual patients. ID-positive lymphocytes not resembling plasma cells have been regularly found in peripheral blood in these diseases. For further characterization ID-positive lymphocytes were enriched from the peripheral blood by affinity chromatography using heterologous anti-idiotypic sera. Two patients with IgG myeloma, one patient with Waldenström's macroglobulinaemia and two persons with benign monoclonal hyperglobulinaemia (BMH) were examined by this technique. The ID-positive PBL population was shown to be heterogeneous with respect to non-tumour-specific surface markers, such as sheep erythrocytes (SRBC), Fc and C receptors. Tumour-specific idiotypic determinants will thus allow a more correct recognition of the total tumour cell compartment in these diseases.