Proliferation and maturation of human bone marrow cells in infectious diseases

In 6 patients with various types of infectious disease an extended study of proliferation and maturation of erythropoiesis and granulocytopoiesis was performed. By means of quantitative 14C-autoradiography DNA synthesis time and labeling index were determined in every morphologically defined cell compartment of both lineages. With these parameters and the relative frequency of cells in the various compartments cell cycle times, relative cell production rates and maturation indices were determined. A general labeling index reduction and prolongation of DNA synthesis time was observed which was statistically significant in the majority of compartments. As a consequence, cell cycle times were prolonged throughout, the deviation from normal increasing with advancing maturation in both lineages. Relative cell production was normal in myelocytes, but elevated in myeloblasts and promyelocytes. On the other hand, proerythroblasts and basophilic erythroblasts showed normal relative cell production rates, while a significantly reduced value was found in polychromatic erythroblasts. The maturation index in both lineages was reduced by roughly 50%. Since cell cycle times were generally prolonged, the most significant deviations from normal being present in the latest proliferative compartments, the low maturation indices are discussed in the light of ineffective erythro- and granulocytopoiesis. Premature cell death in the bone marrow is suggested to be a significant factor in particular cases of infectious disease.