Several investigators have reported patients with acute pure red cell aplas
ia (PRCA) caused by anticonvulsants, antibiotics, or antithyroid agents. Al
lopurinol is known to be a causative agent of aplastic anemia, but there ha
ve been few reports of acute PRCA induced by allopurinol. We describe here
15-year-old boy who suffered from anemia 6 weeks after initiation of allopu
rinol therapy; his anemia immediately improved after cessation of the drug.
His bone marrow showed severe erythroid hypoplasia with a myeloid/ erythro
id ratio of 18.6 and low expression of glycophorin A detected on cell-surfa
ce antigen analysis. No morphological abnormalities were observed in myeloi
d series and megakaryocytes, The prolonged plasma iron disappearance rate a
nd the decreased plasma iron turnover rate also indicated erythroid hypopla
sia. He had been free from any infections, including parvovirus B19, before
manifestation of PRCA, Taken together, these results suggest a diagnosis o
f acute PRCA. This side effect of allopurinol should be taken into consider
ation. Am. J, Hematol, 61:209-211, 1999, (C) 1999 Wiley-Liss, Inc.