Cell production and cell function in human cyclic neutropenia

In vitro studies have been done on haematopoietic cells from a patient with cyclic neutropenia characterized by severe depression of blood neutrophil levels every 21 days. Serial blood counts reveal periodic fluctuations in neutrophils, monocytes and reticulocytes. Agar culture of marrow cells shows normal concentration of colony forming cells. The percentage of colony forming cells in S phase is highly increased during profound neutropenia and normal during the recovery phase relating the granulocyte production to the peripheral neutrophil level. Studies of ingestion rate, bactericidal activity, lactate production and glucose oxidation during phagocytosis in isolated granulocytes show normal results. Also the ingestion rate in isolated monocytes is normal. Serial karyotype analyses of marrow cells during the neutrophil cycle display a normal pattern. Serum myeloperoxidase levels vary inversely with the peripheral neutrophil count indicating increased granulopoietic activity during profound neutropenia, which might be associated with non effective granulopoiesis during profound neutropenia, leading to a lack of granulocyte reserves in the marrow.