Use of hematopoietic growth factors for treatment of aplastic anemia.

To date, six hematopoietic growth factors, granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), interleukin-1 (IL-1), interleukin-6 (IL-6) and erythropoietin (Epo), have been used in the treatment of patients with aplastic anemia (AA). Among them, G-CSF and GM-CSF are effective in correcting neutropenia in some patients with AA, but in general, patients with very severe hypoplasia do not respond to conventional doses of either agent. These factors have been used in the treatment of AA as follows: (1) as adjuvant therapy for severe infections; (2) as adjuvant therapy to immunosuppressive therapy (IS); and (3) as second-line therapy for patients refractory to IS. The results of clinical trials with antilymphocyte globulin, cyclosporine combined with G-CSF have been remarkable both in Europe and in Japan. Ongoing randomized studies with long-term follow-up will reveal the effects of hematopoietic growth factors on both hematopoiesis and the long-term course of the disease, including the later development of clonal disorders.