Erythropoietin and the Regulation of Erythropoiesis in DiGuglielmo’s Syndrome

Observations relating to the regulation of red cell production in four patients with DiGuglielmo’s syndrome and one with malignant lymphoma are presented. Erythropoiesis in these patients was characterized by bizarre forms, marked erythroid hyperplasia and ineffective erythropoiesis. Erythropoietin excretion was elevated, in keeping with the degree of anemia. Hypertransfusion of these patients resulted in a marked decrease in erythropoietin excretion and a reduction in marrow erythroid hyperplasia although morphologic abnormalities of the individual cells in both granulocytic and erythroid cell lines remained. The alteration in marrow function in response to transfusions was reflected by the E:G ratio and in iron kinetic and reticulocyte measurements which demonstrated a decline in both total and effective erythropoiesis. It is concluded that proliferation of the erythroid marrow in these patients is under physiologic regulation and that the defects observed are expressed during cell maturation.