Neutrophils' atomic force microscopy in COPD with pulmonary hypertension (PH)

Abstract

Background: The assessment of structural and viscoelastic characterization of neutrophils by means with atomic force microscopy (AFM) may provide further insight in the clarification of the role of chronic inflammation in the development PH in COPD. Aims: To explore the ultrastructure, membrane stiffness (Young9s modulus) and force of adhesion of peripheral blood neutrophils by means of AFM technique in COPD patients with PH. Methods: Measured the height of the cell and granules of the cytoplasm (nm), cell and nucleus area (nm 2 ). Force spectroscopy mode was used for quantitative estimation of the young9s modulus of the membrane and the force of adhesion of neutrophils in COPD patients without PH (n15). PH in COPD patients was defined by means of Doppler technique as systolic pulmonary artery pressure (SPAP) > 40 mm Hg. Results: COPD patients with PH (n14; 53,3±5,2 yrs) and without PH (n15; 52,3±4,6 yrs) and healthy controls (n14; 50,3±5,7 yrs) were included into study. In comparison with healthy controls in COPD patients with PH the neutrophil area (112,78±13,3 vs 124,78±20,73 nm 2 ) and the nucleus area (30,38±0,04 vs 39,16±7,67 nm 2 ) were reduced, the height of the cytoplasm granules was increased (1,41±0,19 vs 1,01±0,02 nm). The stiffness of the membrane (38,8±1,43 vs 15,29±0,22 κPa) and the force of adhesion (0,48± 0,04 vs 0,076±0,001nN) of neutrophils were higher than in the control. There was a significant correlation of the membrane stiffness the force of adhesion with the SPAP (r=0,83 and r=0,61, respectively). Conclusions: The ultrastructure and viscoelastic properties of neutrophils in COPD patients with PH differ from healthy controls and may reflect the severity of PH.