Dyserythropoiesis and erythroblast-phagocytosis preceding pure red cell aplasia

A 50-year-old woman with typical acquired primary pure red cell aplasia (PRCA) was successfully treated with prednisone. A later relapse was preceded by a period of ineffective erythropoiesis characterized by a reticulocyte response inappropriately low for the degree of anemia, serum iron of 189 micrograms/dl, total iron-binding capacity (TIBC) of 213 micrograms/dl, and erythroid hyperplasia. In addition there was marked dyserythropoiesis and erythroblast-phagocytosis. One month later, bone marrow examination showed classic PRCA. This rarely reported evolutionary stage of PRCA has several implications: 1) it suggests antibody induced erythroblast cytotoxicity as one mechanism of PRCA; 2) at a particular time in the development of PRCA there is potential for misdiagnosis as primary refractory anemia (PRA); and 3) some cases of PRA with similar morphologic and laboratory findings may be pathogenetically related to PRCA and may benefit from evaluation for immune-mediated suppression of erythropoiesis.