Nonsecretion of myeloma protein in spite of an increase in tumor burden by chemotherapy

Abstract

A unique case of IgA κ myeloma is presented. While the myeloma cells had secreted a large quantity of IgA κ monoclonal protein, they were induced to stop secreting the monoclonal protein by cyclophosphamide and vincristine, in spite of a remarkable increase in tumor burden. The absence of intracytoplasmic IgAκ was clearly evidenced by the immunofluorescence technique using anti-IgA and anti-κ monoclonal antibodies.