Dyserythropoiesis , Refractory Anemia , and “ Preleukemia : ”

Twenty-one enzymatic activities and red cell glutathione content are compared in cord blood, dyserythropoietic disorders, normal subjects, and subjects with hemolytic syndromes and reticulocytosis approximating that of the newborn. The dyseryth ropoietic states are heterogeneous and include several hereditary disorders, “preleukemia” and overt leukemia, refractory anemia with and without marrow ringed sideroblasts, and folate deficiency. Many activities exceeded those of cord erythrocytes and “high reticulocyte” controls by one or even several standard deviations. The low phosphoglycerate kinase and glutathione peroxidase and relatively low ribosophosphate pyrophosphokinase and adenine-phosphoribosyl transferase of cord erythrocytes were mimicked uncommonly. Pyruvate kinase was often relatively or absolutely low and sometimes dramatically so. Enzyme ratios were grossly aberrant. Capricious very high individual activities occurred in some instances. The heterogeneous nature of case material, including both hereditary and acquired syndromes, renders it difficult to interpret similarities often seen from case to case and sometimes to cord blood patterns on the basis of the reversion to fetal erythropoiesis as a common denominator. Rather, the cytoand karyokinetic abnormalities characterizing dyserythropoiesis of diverse etiologies may result in exaggerations and distortions of a normal asynchronism in loss of functional genetic material governing enzyme synthesis as the nucleus degenerates and cytoplasmic organelles are lost.