Mitogen induced cellular cytotoxicity (MICC) in multiple myeloma.

Mitogen induced cellular cytotoxicity (MICC) was noted to be markedly increased in patients with multiple myeloma as compared to normal controls and to patients with chronic lymphocytic leukemia (CLL). Enhanced MICC was present at various effector-to-target cell ratios and at several mitogen concentrations. Removal of adherent, phagocytic cells by carbonyl iron, glass wool, or rayon columns abolished the MICC response from the peripheral blood of both multiple myeloma patients and normal controls. Thus, the effector cell mediating MICC may be monocytic in origin and closely resembles the suppressor cell for immunoglobulin synthesis described in patients with multiple myeloma. Our data suggest that the MICC assay with chicken red blood cells as targets may provide a convenient method for identifying pathologic conditions where this cytotoxic effector cell population plays an active role.