MPO and chronic obstructive pulmonary disease: Abbreviations: COPD = chronic obstructive pulmonary disease,hsCRP = high sensitivity C reactive protein,EC = endothelial cells, ICAM-1 = intercellular adhesion molecule1, LpPLA2 = lipoprotein-associated phospholipase A2, MPO = myeloperoxidase,NK cells = natural killer cells,VEGF = vascular endothelial growth factor, VCAM-1 = vascular cell adhesion molecule 1