Defective erythroid progenitor differentiation system in congenital
hypoplastic (Diamond-Blackfan) anemia
JM Lipton, M Kudisch, R Gross and DG Nathan
To explore the etiology of congenital hypoplastic or Diamond-Blackfan
anemia (DBA) we investigated in vitro erythropoiesis in nine patients. Of
the nine, seven were clinically responsive to prednisone. Four were infants
evaluated at the time of diagnosis. Six were never or were only minimally
transfused. Those for whom prednisone had been prescribed had discontinued
the drug a minimum of five months prior to study. The bone marrows of these
nine patients were compared with those of hematologically normal
individuals and with those of four patients with transient
erythroblastopenia of childhood (TEC) whose erythroid aplasia was as severe
as that of the patients with DBA. Using the plasma clot semisolid culture
technique to enumerate erythroid progenitors and to evaluate the growth
characteristics of the colonies to which they give rise, we concluded that
at the onset of DBA: (a) erythroid progenitor frequency does not correlate
with the degree of anemia and erythroblastopenia; (b) erythroid progenitor
differentiation may in some cases be abnormally insensitive to crude
preparations of erythropoietin; and (c) progenitor erythropoietin
insensitivity in vitro does not necessarily indicate prednisone
insensitivity in vivo. Thus, DBA does not appear to be solely the result of
deficient formation of erythroid progenitors but is, in addition, a
disorder that is due to defective progenitor differentiation in vivo.
Volume 67,
Issue 4,
pp. 962-968,
04/01/1986
Copyright © 1986 by The American Society of Hematology
