Erythropoiesis and Ferrokinetics in Chronic Respiratory Disease

Abstract

The hematopoietic response to long standing hypoxia was assessed in 25 patients with chronic respiratory disease. The respiratory studies consisted of spirometry, measurement of distribution of inspired air, and blood and expired gas analysis. The hematologic and blood volume studies included leukocyte counts, hematocrit and hemoglobin estimation, measurement of total red cell mass by Cr51 tagging and plasma volume by T 1824, RISA, or both. Ferrokinetic studies were done with Fe59. Patients with hypoxia due to chronic bronchitis and emphysema, as well as other respiratory diseases, developed secondary polycythemia which was roughly proportional to the hypoxic stimulus. Secondary polycythemia was present with a normal hematocrit in some patients with chronic cardiorespira-tory disease and was best demonstrated by measurement of the red cell mass. The plasma Fe59 disappearance rate (Fe59 t/2) was related to the arterial oxygen tension, being shorter in patients with lower oxygen tensions. There was delayed and incomplete incorporation of Fe59 into the erythrocytes of patients with chronic bronchitis and emphysema. Fe59 incorporation was normal in the other patients studied.