Aplastic Crisis or Erythroid Hypoplasia in Sickle Cell Disease?

Abstract

To the Editor.— A recent letter by Rosner1is critical of the use of the term "aplastic crisis" to describe the transient red cell aplasia occasionally observed in association with human parvovirus B19 infection2-5in children with sickle cell disease or other hereditary hemolytic anemias. Rosner contends that the phrase "aplastic crisis" is a misnomer because only "erythroid hypoplasia" occurs in this clinical entity. Whereas erythroid hypoplasia is the principal and most consistent hematologic manifestation in parvovirusinduced aplastic crisis, transient thrombocytopenia2-4and leukopenia3,4or neutropenia5occasionally have also been observed in association with aplastic crisis. Erythroid hypoplasia is also observed in other disease states with transient or chronic bone marrow failure, eg, in aplastic anemia or in transient erythroblastopenia of childhood. The exclusive use of the term "erythroid hypoplasia" in place of "aplastic crisis" to describe the clinical entity of transient parvovirus-induced bone marrow aplasia