Subpopulations of T-lymphocytes in multiple myeloma.

The percentage and absolute numbers of T lymphocytes bearing Fc receptor for IgG and IgM were evaluated in 13 patients with multiple myeloma and in a group of controls of the same age range. An increase in the percentage of the TG cells was found, whereas TM cell numbers were not different from those of the controls. In order to better define the properties of the TG lymphocytes, their ability to suppress the PWM-induced B cell differentiation was tested in an in vitro experimental assay. TG cells from multiple myeloma exert a suppressor activity as the TG of the controls in this system. The possible interpretation of suppressor T cell increases in these patients is discussed.