Exudative indices in airways inflammation

Airways inflammation has come to be equated with the presence of inflammatory cells and their products in airway lumen and tissue. However, the inflammatory condition must also, or rather, be determined by indices which show to what degree the tissue itself is affected by the process. Plasma exudation from abundant subepithelial microvessels is a specific defence/inflammatory tissue response to mucosal provocations; promptly after extravasation, the plasma exudate reversibly and non-injuriously creates intercellular pathways across the mucosa; the exudate enters the airway lumen without compromising the epithelial lining as a barrier to luminal solutes; there is a good correlation between surface and tissue plasma exudates. I propose that plasma tracers on the mucosal surface can identify the ongoing airway inflammation, its intensity and time-course in great detail.