Increase of serum interleukin-2 and regression of myeloma after rhGM-CSF treatment of drug induced bone marrow aplasia

Recombinant human granulocyte/macrophage colony-stimulating factor (rhGM-CSF) was administered to a patient with multiple myeloma (IgA, stage IIA) who had a chemotherapy-induced bone marrow aplasia with granulocytopenia complicated by severe pneumonia and septicemia. The rhGM-CSF was given as i.v. infusions, 300-400 micrograms daily, for three weeks. The patient responded both hematologically and clinically with improved granulocyte counts and clearance of massive pulmonary infiltrates. We also observed a partial remission of the myeloma with decreasing s-IgA levels and reduced plasma cell infiltration of the bone marrow during a period of up to four months after the rhGM-CSF treatment. Immunological studies performed during and after cytokine administration showed an increase in serum interleukin-2 (IL-2) levels and HLA-DR positive T-lymphocytes indicating an activation of the immune system. It is suggested that rhGM-CSF induced immunological changes which may have contributed to the partial regression of the myeloma.