The lungs and platelet production

Several studies have suggested that thrombopoiesis may occur in the lungs. To investigate the role of the lungs in platelet production, we measured automated platelet parameters in blood from the pulmonary artery and the radial artery (n=125) or aorta (n=26) in patients undergoing aorto-coronary bypass. No significant differences were found between pulmonary and radial arterial blood with regard to platelet count (192.132 +/- 46.250 vs. 192.004 +/- 46.294 x 10(9)/l), mean platelet volume (11.03 +/- 1.04 vs. 11.03 +/- 1.03 fl), plateletcrit (0.212 +/- 0.051 vs. 0.212 +/- 0.051 x 10(-2)), platelet distribution width (14.48 +/- 2.16 vs. 14.47 +/- 2.08 fl) and platelet-large cell ratio (0.350 +/- 0.076 vs. 0.351 +/- 0.078). Similar results were obtained in comparisons between pulmonary arterial and aortic blood. A coefficient of linear correlation of 0.98 was found between the pulmonary and radial arterial and aortic platelet counts. These findings suggest that the platelet population entering the lungs was the same as the platelet population leaving them. Our results do not therefore support the theory of pulmonary platelet production.