Studies on human preleukaemia. I. Erythroblast and iron kinetics in aregenerative anaemia with hypercellular bone marrow.

In 34 patients with aregenerative anaemia and hypercellular bone marrow, a condition earlier suggested to be of a preleukaemic nature, erythroblast thymidine labelling indices (LI) were significantly decreased, as would be expected in preleukaemia. The 59Fe erythrocyte incorporation after 2 weeks was generally low. The 59Fe plasma clearance was fast in 22 of 31 patients, normal in 5 and moderately prolonged in 4. These 4 patients had a low relative number of erythroblasts in the marrow. A significant relationship between the marrow erythroblast number and the 59Fe plasma clearance could be demonstrated. Cases with an increased number of mueloblasts in the marrow did differ significantly from the rest in LI and iron incorporation.