Abnormal Nucleic Acid Metabolism of Lymphocytes in Plasma Cell Myeloma and Macroglobulinemia

I NCREASED NUMBERS of plasmacytoid cells, associated with the formalion of large amounts of monoclonal proteins is characteristic of plasma cell myeloma and macroglobulinemia of Waldenstr#{246}m. Although aberrations of the immune response1 are present in both diseases, patients with myeloma are particularly prone to bacterial infections.1’2 In the malignant lymphoid disorders of chronic lymphocytic leukemia3 and generalized Hodgkin’s disease,4 the transformation response of lymphocytes to phytohemagglutinin (PHA) is impaired. Using the incorporation of radiolabeled nucleosides into lymphocyte desoxyribonucleic acid (DNA) and ribonucleic acid (RNA), we have studied patients with myeloma and macroglobulinemia, and correlated the in vitro cellular responses with serum immunoglobulin levels and past history of infection. The results demonstrate significant impairment of lymphocyte responsiveness to PHA in these disorders.