Lymphocyte subsets in the peripheral blood of patients with multiple myeloma and benign monoclonal gammopathy.

A panel of monoclonal antibodies that identify various antigens present on T and B cells was used to characterize circulating blood lymphocyte subsets in multiple myeloma [(MM)--13 patients] and benign monoclonal gammopathy [(BMG)--5 patients]. In MM and BMG an increase in B cell proportions (BA 1 positive cells) was observed, whereas T cells (Lyt 3 positive cells) were reduced compared to normal controls. However, with respect to the T cell subset distribution, a marked diversity between MM and BMG was noted. This may help to differentiate BMG from MM. In MM a relative decrease in inducer/helper T cells (OKT 4 positive cells) and increase in suppressor/cytotoxic T cells (OKT 8 positive cells) as well as in NK/K T cells (Leu 7 positive cells) was observed. On the other hand, in BMG the relative T cell subset distribution was comparable to those seen in normal subjects.