[Fc gamma+ T-lymphocytes and depressed polyclonal immunoglobulin synthesis in multiple myeloma].

In the present study the effects on the polyclonal Ig synthesis of peripheral MM T gamma and T non-gamma cell fractions when cocultured with autologous and normal allogenic B-lymphocytes have been reported. Five untreated MM patients (three IgG-kappa, two IgG-lambda) were studied employing a five-day PWM-stimulated co-culture technique, in which the percentage of cells with detectable amounts of cytoplasmic Ig was evaluated by direct immunofluorescence. Our results indicated that depressed polyclonal Ig synthesis in human MM could be ascribed not only to an increased "suppressive" activity of T gamma cells but also to an impaired "inducer" function of T non-gamma lymphocytes and to an intrinsic B-lymphocyte disfunction as well. In addition, it was noteworthy that MM T gamma cells showed on normal Ig synthesis a selective suppressive effect mainly for those Ig chains corresponding to the monoclonal Ig which characterizes the own myeloma type. The significance of this datum, so far not yet reported, remains to be established.