Hemoglobin content of individual erythroblasts in hematopoietic dysplasia: marked heterogeneity at late stages of maturation.

Defective hemoglobin synthesis and gross morphologic abnormalities of erythroblasts are striking features of hematopoietic dysplasia. In order to define the effects of defective hemoglobin synthesis on hemoglobin content of erythroblasts at each stage of maturation, we measured the hemoglobin content and concentration of individual erythroblasts at various stages of maturation in the bone marrow by scanning microspectrophotometry. In contrast to normal erythroblasts, those from hematopoietic dysplasia had decreased hemoglobin content and decreased hemoglobin concentration at late stages of maturation. This observation, together with the observed near-normal hemoglobin content and concentration of circulating red cells in this disorder, suggests that polychromatophilic erythroblasts with decreased hemoglobin content fail to complete normal maturation. The abnormalities in hemoglobin content observed in vivo in hematopoietic dysplasia could be reproduced in the in vitro cultures of erythroid progenitors of bone marrow cells from the patients.