Attempt at quantification of the cytotoxic drug-induced changes of the human bone marrow compartments.

In order to describe the changes of the human bone marrow compartments after repeated courses of adriamycin/cyclophosphamide in quantitative terms, 2 methods have been studied for their usefulness as indices of bone marrow cellularity: cell counts per ml of bone marrow aspirates obtained under standardized conditions, and cell counts per microliter of bone marrow spicules evaluated by morphometric techniques. Applied to a sufficiently large group of patients, both methods were useful to describe the cytotoxic drug-induced changes of the bone marrow compartments in accordance with the following indirect criteria: (a) the results in man are quite compatible with the changes of haematopoiesis described in animal experiments after cytotoxic drugs; (b) the changes of the peripheral blood cell pools - PMN and reticulocytes -, which can be assessed quantitatively, correspond to the changes of the respective bone marrow pools as determined by the described indices of cellularity; (c) this quantitative description of drug-induced changes in the human bone marrow compartments yields 'reasonable' results on the basis of both the mechanism of action of the cytotoxic drugs employed and the kinetics of the haematopoietic system studied.