The Presence of Deoxyribonucleic Acid (DNA) Synthesizing Cells in Patients with Refractory Anemia

An autoradiographic technic with tritiated thymidine to label cells in the peripheral blood undergoing DNA synthesis, has been utilized to study patients with refractory anemia. Included in this study are patients with aplastic or hypoplastic anemia and acquired hemolytic anemia. Patients with anemia and chronic renal failure and normal persons as controls have been included. The patients with aplasia, with no history of exposure to toxic agents, showed a marked increase in labeling index, whereas the patients with a history of exposure to toxic agents showed a normal labeling index. The patients with refractory hemolytic anemia and positive Coombs’ test revealed a marked increase in labeling. The cells revealing the increased labeling have the morphologic characteristics of the young lymphocyte. The hypotheses have been put forward that the cases of aplasia showing an increased labeling index together with the cases of refractory hemolytic anemia may be explained on an auto-immune basis or an increased number of circulating totipotential cells in response to the anemia.