Severe anemia due to transient pure red cell aplasia in early childhood. Arrest at the level of the committed stem cells?

Five patients, 11 months to 3 4/12 years old with severe normochromic, normocytis anemia and reticulocytopenia are reported. At the height of erythropoietic arrest when erythroid precursor cells were completely absent, undifferentiated stem cells (transitional cells), accumulated in the bone marrow. They disappeared again upon spontaneous resumption of erythropoiesis. We suggest that the erythropoietic arrest had occurred at the level of the hematopoietic stem cell. All patients recovered within 1 week of diagnosis. No steroid therapy was given. Failure to recognize this clinical entity leads to unnecessary diagnostic and therapeutic procedures including the transfusion of blood.