[OKT-8+ suppressor T-lymphocytes are increased in patients with stable multiple myeloma]

T-lymphocyte subpopulations were studied in 68 patients with monoclonal gammopathies and 27 age-matched healthy controls using the monoclonal antibodies (mAb) OKT-3, OKT-4 and OKT-8. 13 patients had untreated multiple myeloma (MM), 51 had MM and were receiving intermittent pulse chemotherapy or were in remission and followed up without treatment. Four patients had a monoclonal gammopathy of unknown significance (MGUS). Analysis of the data for disease activity demonstrated a significant imbalance of T-lymphocyte subpopulations in patients with stable (plateau phase) MM. In these patients the relative number of cells with suppressor phenotype (OKT-8 positive) was significantly increased (p less than 0.0001) and the relative number of cells with helper phenotype (OKT-4 positive) significantly decreased (p less than 0.0001) when compared with normal controls or patients with active MM. Patients with stable disease also had a significantly higher absolute number of OKT-8 positive cells than patients with active MM (p = 0.04). Additionally, in vitro functional studies showed significant suppression of clonal growth of the human myeloma cell line (RPMI 8226) by a soluble suppressor factor of OKT-8 positive cells from the peripheral blood of healthy donors as well as from bone marrow aspirates of patients with MM. These findings support the hypothesis that T-lymphocyte subpopulations play an important role in the control of proliferation of the myeloma cell clone in patients with low cell mass (stable phase) multiple myeloma.