Multiple Myeloma and Benign Monoclonal Gammopathy: Differentiation by Immunofluorescence of Lymphocytes

Abstract

The proportions of T and B cells among peripheral blood lymphocytes were studied in 46 patients with plasma cell myeloma and in 14 patients with benign monoclonal gammopathy. Significant lowering (P < 0.001) of percentages of B cells having normal surface Ig was found in the myeloma group, whereas the patients with benign M-components showed normal proportions of B cells. Mean percentage of total B cells in myeloma patients was 10.3% ± 6.9%, whereas mean B-cell value in benign monoclonal gammopathy was 21.4% ± 11.7%. Normal B-cell values were 22.9% ± 7.1%. Myeloma patients in remission tended to have normal proportions of B cells. Individually specific or idiotypic M-component antigenic Ig markers were present in relatively high percentages in peripheral blood lymphocytes from two patients with myeloma, whereas the reverse was true in a patient with a benign M-component. There was some overlap in total B-cell values between patients with established myeloma and those with benign monoclonal gammopathy.