The oxygen tension-platelet relationship in cystic fibrosis.

Abstract

The mean platelet count of 103 patients with cystic fibrosis was increased to 398,000 per mm3. All of the patients had varying degrees of long-standing hypoxemia, with a mean arterialized capillary blood oxygen tension (Po2) of 66 mm Hg. There was an inverse correlation between the Po2 and platelet concentrations in spite of the findings of lower platelet counts among the older patients and the lack of a relationship between age and Po2. Of equal and puzzling significance was the evidence of an oxygen-platelet relationship in the patients with chronic pulmonary disease that was opposite to the direct relationship previously found in patients with cyanotic congenital heart disease. In this regard, it is possible that the dynamics and the anatomy of the pulmonary vascular bed in two different hypoxic disorders may play a significant role in platelet response and release. These two disorders may, in effect, be an experiment in nature relative to the differences in arterial and venous platelet concentrations....