Blood lymphocytes in myeloma patients; high percentage of complement receptor bearing cells is accompanied by decreased anti-immunoglobulin (Ig) binding capacity

Abstract

Receptor functions of peripheral blood lymphocytes of 60 myeloma patients have been studied. Cell surface immunoglobulin, spontaneous rosette formation with SRBC, complement receptors using EAC rosette formation and uptake of radioiodinated antibodies against human Ig have been examined and compared to the results obtained with cells from normal individuals. Also the response to polyclonal B cell activators has been studied. Significant differences between normal individuals and myeloma patients have been found for the numbers of EAC rosette forming cells. The binding capacity for radiolabelled anti-Ig antibodies showed a strong tendency to low values in the patient group. Our results are compatible with the idea that cells with an exclusive capacity for complement binding are increased in myeloma patients. A high number of EAC binding cells has been found also in bone marrow aspirates of myeloma patients showing infiltration by tumor cells. Therefore, it seems possible that the site primarily affected from disease is the main source of complement receptor bearing cells. No correlation has been seen between the response to polyclonal B cell activators or the concentration of normal serum Ig to the frequency of EAC binding cells in individual patients (r s 0.07 and 0.11, respectively).