A Study of Erythropoiesis by Combined Morphologic, Quantitative Cytochemical and Autoradiographic Methods : Normal Human Bone Marrow, Vitamin B₁₂ Deficiency and Iron Deficiency Anemia

The relationship between the morphology of human erythropoietic cells and their position in interphase has been studied. In normal bone marrow, pro-normoblasts, basophilic normoblasts and early polychromatic normoblasts were present in all stages of interphase. It has been shown that a significant increase in nuclear size occurs as a cell moves through its cell cycle, in both normal and megaloblastic erythropoiesis.

The relative distribution of the basophilic erythropoietic cells and the dividing polychromatic cells, in the various stages of interphase, has been determined in normal bone marrow, vitamin B₁₂ deficiency and iron deficiency anemia.

In vitamin B₁₂ deficiency, associated with moderate or severe anemia, there was an increased proportion of cells in G₂, and there were several cells with DNA contents that were between the 2c and 4c values, which were not in DNA synthesis as judged by ³H-TdR labeling. These abnormalities were most pronounced in the dividing polychromatic cell group. Similar abnormalities were not present in iron deficiency anemia, indicating that these disturbances were not produced by the presence of anemia per se. The possible relationship between these changes in the cell cycle and the ineffective erythropoiesis seen in anemia due to vitamin B₁₂ deficiency has been discussed.