Erythroblastopenia in two patients after splenectomy and polychemotherapy

Acquired erythroblastopenia is a rare disorder of the hematopoietic system associated with viral infections, autoimmune diseases, and drugs. We report on two patients who became anemic due to maturation-arrest at the proerythroblast level, without alterations of white blood cell or platelet counts. Both patients had been splenectomized and had undergone chemotherapy for nephroblastoma or Hodgkin's disease, respectively, at the same pediatric oncology unit. Erythropoietin levels were elevated in both patients. Antibodies against specific viruses, particularly parvovirus B 19, could not be detected in patient sera. Both patients responded to infusions of 7 S immunoglobulin with a rapid increase of the reticulocyte counts. In both cases, complete clinical remission was observed after a duration of 5 months. Heat-inactivated serum obtained during the acute phase and after remission as well was found to be inhibitory for normal bone marrow granulocyte and erythrocyte progenitor growth in vitro. The simultaneous appearance of this rare disorder in two otherwise unrelated patients treated at the same unit prompts speculations about a viral etiology.