A role of endothelial dysfunction for development of microcirculation and cardiopulmonary blood flow abnormalities in patients with COPD and different alpha-1-antitrypsin phenotypes

Abstract

The aim of this study was to investigate structural and functional changes of pulmonary vessels and cardiopulmonary blood flow in COPD patients with different alpha-1-antitrypsin (A1AT) phenotypes and endothelial dysfunction. Methods. Patients with COPD stage 2 to 3 (n = 113) with different A1AT phenotypes underwent clinical and radiological examination; endothelial dysfunction markers were measured. Results. More severe COPD was associated with more severe pulmonary microcirculation disorders and more significant perfusion defects. Patients with ZZ phenotype had worse pulmonary blood flow abnormalities compared to patients with MM phenotype. Pulmonary blood flow abnormalities were closely related to endothelial dysfunction (r = 0.75) and were more significant than structural abnormalities diagnosed on multi spiral computed tomography. Severe disorders of pulmonary blood flow were not accompanied by severe pulmonary hypertension. Conclusions: Blood levels of main endothelial dysfunction markers were directly related to COPD severity. Angiotensin-converting enzyme concentration was significantly below the normal level and was related to pulmonary artery pressure. The pulmonary blood flow differed in patients with different A1AT phenotypes and COPD stage 3 or higher. Perfusion defects were more severe in patients with ZZ phenotype.