Characterization and Significance of Circulating Microvesicles in Pulmonary Hypertension Due to Chronic Obstructive Pulmonary Disease

Mild to moderate pulmonary hypertension is a common complication of chronic obstructive pulmonary disease (COPD); such a complication is associated with increased risks of exacerbation and decreased survival. A small proportion of COPD patients may present with severe pulmonary hypertension, defined by a mean pulmonary artery pressure more than 35 mmHg (or more than 20 mmHg with a low cardiac index < 2 l/min/m2) with pulmonary vascular resistance more than 3 Wood units, measured by right heart catheterization (RHC). In these patients, pulmonary microvessels remodeling is the main cause of increase in pulmonary arterial pressure and is thought to result from the combined effects of hypoxia, inflammation, and loss of capillaries but the mechanisms are complex.

For these patients, no drugs have been approved for treatment and lung transplantation must be considered for the more severe patients who are eligible. A better characterization of these patients is needed.

We hypothesize that microvesicles generation and endothelial damage could be related to the severity of pulmonary hypertension due to COPD, assessed by pulmonary hemodynamic parameters. Circulating biomarkers of vascular damage and cell activation will be measured in blood samples from 80 COPD patients who have hemodynamic assessment by RHC. To go further, the origin of the particles will be characterized.