Refractory anemia with hyperplastic bone marrow: subclassification based on responsiveness to erythropoietin in vitro.

The responsivenes to erythropoietin of cultured bone marrow cells, obtained from 7 patients with refractory anemia with hyperplastic marrow, was studied. 5 of these patients' marrows also exhibited sideroblasti changes. Heme synthesis in cultured bone marow cells was either responsive to stimulation by erythropoietin, or completely refractory. The sensitivity of the bone marrow cells to the hormone was not related to either the clinical or laboratory findings.