A Study of Ineffective Erythropoiesis in Sideroblastic Anaemia and Erythraemic Myelosis

Erythropoiesis has been studied in three patients with sideroblastic anaemia and one case of erythraemic myelosis. The marrows showed erythroid hyperplasia, plasma iron turnover was high, red cell iron utilization low, and retention of 59Fe prolonged in the marrow. A combined quantitative cytochemical and autoradiographic analysis showed an accumulation of early polychromatic cells in G2 and the presence of several cells which were apparently arrested after a period in DNA synthesis. DNA synthesis was rarely seen in cells with pronounced siderotic deposits. These results indicate the presence of ineffective erythropoiesis with a disturbance in the progress of early polychromatic cells through interphase, probably leading to intra‐marrow cell death. In erythraemic myelosis there was also a reduced red cell production due to faults of cell division; the nature and consequence of the bizarre forms of cell replication are discussed.