Collection of Nasal Secretions and Tears and Their Use in Allergology

Sveva Castelli; Stefania Arasi; Ruby Pawankar; Paolo M. Matricardi


Curr Opin Allergy Clin Immunol. 2018;18(1):1-9. 

In This Article

Nasal Secretion Production and Composition

Nasal secretions derive from four major sources: seromucous submucosal glands, globet cells, transepithelial transport of ion and water, and plasma transudate.[10] Their volume is augmented by fluid from the lacrimal glands through the nasolacrimal duct and condensed water at the mucosal surface during expiration.[11] The mucus blanket laying on the respiratory epithelium exists as a bilayer fluid, with a surface gel phase and an aqueous periciliary sol layer.[12] It contains 95% water, 2% mucin, 1% electrolytes, 1% lipids, 1% of other proteins, such as albumin, immunoglobulins, lysozyme, kallikrein, and lactoferrin.[13] Albumin represents about 15% of total protein in resting secretions, suggesting that transudation occurs under normal conditions.[14] Albumin secretion increases under inflammatory condition, reflecting increased vascular permeability.[15] The mucus glycoproteins, secreted principally from submucosal glands, give the mucus its characteristic viscoelastic properties.[16] Critical functions of human respiratory secretions are protection of the mucosa and essential host-defence, mainly through proteins secreted by serous cells in the submucosal glands.[12]