Stimulation of myelopoiesis in chronic lymphocytic leukemia and in other lymphoproliferative disorders by recombinant human granulocyte-macrophage colony-stimulating factor

Abstract
In an attempt to stimulate granulopoiesis, we administered recombinant human granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) to 11 patients with lymphoprolif‐erative disorders. Ten patients had neutropenia, six of whom had severe neutropenia ( 65‐fold) and monocytes (1.3‐ to >5‐fold) increased as well. In contrast, no significant increases were seen in total lymphocytes or in different phenotypic subsets of lymphocytes during treatment. The overall proportion of myeloid and lymphoid elements in bone marrow remained stable. These results indicate that GM‐CSF is effective in stimulating myelopoiesis in neutropenic states associated with lymphopro‐liferative disorders. Further studies will be necessary to determine whether the correction of neutropenia ultimately translates into clinical benefit.