Effect of low‐dose granulocyte‐macrophage colony‐stimulating factor (LD‐GM‐CSF) on platelet transfusion‐dependent thrombocytopenia

Granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) is a hematopoietic growth factor known to promote the proliferation and differentiation of precursors of granulocytes and monocytes. GM‐CSF at standard doses (125–500 μg/m²) alleviates neutropenia secondary to cytotoxic chemotherapy, myelodysplastic syndromes, and aplastic anemia, but has minimal effect on anemia or thrombocytopenia. GM‐CSF at doses <30 μg/m² has been reported to improve platelet counts in some patients exhibiting cytopenia related to hematologic disorders such as aplastic anemia and myelodysplastic syndrome. Lowdose GM‐CSF (10–20 μg/m²) was evaluated in 20 patients with transfusion‐dependent thrombocytopenia persisting after myeloablative cytotoxic chemotherapy or with disease‐related cytopenia. Seven patients (35%) responded as defined by a reduction in the platelet transfusion requirements by at least 75%. Low‐dose GM‐CSF did not significantly increase neutrophil counts or decrease red blood cell transfusion requirements. These results indicate that low‐dose GM‐CSF has a thrombopoietic effect in about one‐third of patients with platelet transfusion‐dependent thrombocytopenia which has not been observed at higher doses. © 1994 Wiley‐Liss, Inc.