Why Measure EBC pH?
To answer this question requires consideration of how inflammation damages the airways and lungs. Inflammatory cells do not cause host damage just by sitting around, nor by releasing cytokines or other mediators. Inflammation damages the host in many of the same ways that it was designed to damage invading microorganisms. These mechanisms principally include: • Release of enzymes that allow access of phagocytic cells to subepithelial microorganisms. The classic example is neutrophil elastase, which drills holes in tissue to allow tissue neutrophil miration to get the site where those bacteria are. Release of proteins toxic to organisms that also have toxicity to human tissue: eosinophil proteins such as Major Basic Protein and Eosinophil Cationic Protein come to mind. Probably designed to assist in burrowing through the surface of a worm, these proteins aren’t too intelligent and will do the same to the surface of the airway. • Release of oxidants, such as derived from neutrophil oxida
