The Erythropoietic Factor in Hypoxic Patients With Emphysema Without Secondary Polycythemia

Many patients with chronic hypoxia due to pulmonary emphysema fail to develop a secondary polycythemia. 1,2 When polycythemia does occur in such patients it is often less than that which a normal person would develop if exposed to a similar degree of hypoxia. 3 Many have sought an explanation for this unresponsiveness of the emphysematous patient to the hypoxic stimulus. There is agreement that some emphysematous patients fail to develop polycythemia owing to a failure of erythropoiesis. 2 Although such patients frequently have chronic pulmonary infections, a critical study of their hemopoietic dynamics does not yield information similar to that found in the anemia of infection. 2,4 There is increasing evidence to suggest that the hypoxic stimulus to erythropoiesis is mediated by a humoral factor, erythropoietin. 5-7 The biological assay of this humoral factor in the plasma of unresponsive patients with emphysema has not been documented. The present report is concerned with the assay for