Effect of oxymetholone on human cyclic haematopoiesis.

A 62-year-old woman had recurrent fluctuations of neutrophil, monocyte, reticulocyte and platelet counts with a cycling time of 38.5 d. Periodic fluctuations of granulo-, erythro- and megakaryopoiesis were also demonstrated in her bone-marrow. Oxymetholone reduced the magnitude of the profound cyclic fluctuations in all these cell lines. During treatment a reduced number of in vitro CFU-C of the progenitor myeloid series from the bone marrow was observed. Using the patient leucocytes as feeders for normal control marrow cells, indication was found for a fluctuation in colony stimulating activity in vitro, rising above normal at the nadir of the WBC.