Glycoconjugate Expression of Sinus Mucosa in Chronic Rhinosinusitis: A Lectin Histochemical Study

Abstract

Background

Glycoproteins are responsible for the rheological properties of the mucus. Changes in mucus viscosity may interfere with mucociliary clearance, leading to stasis and aggravation of chronic rhinosinusitis (CRS). The purpose of this study was to assess the composition and concentration of various sinus mucosa glycoproteins in normal and chronically inflamed sinuses.

Methods

A semiquantitative scoring system was used to express the binding intensity of 10 lectins to 6 carbohydrates (galactose, sialic acid, N-acetylglucosamine, N-acetylgalactosamine [GalNAc], fucose, mannose) residing in the sinus mucosa of patients with CRS (N = 20) and normal controls (N = 10).

Results

The mean CT score, compatible with extensive sinus disease, was 13.9 ± 6.7. All six carbohydrates were found in the epithelium and submucosal glands of patients and controls. Peanut agglutinin staining showed significantly higher concentration of disaccharide galactose beta 1,3 GalNAc in epithelial goblet cells and in submucosal mucous and mixed glands of patients compared with that of controls (p = 0.01, p = 0.03, and p = 0.018, respectively). The epithelial glycocalyx of patients was also significantly more abundant in fucose and in GalNAc (p = 0.015, and p < 0.001, respectively).

Conclusion

Glycoconjugate expression of the sinus mucosa in CRS is markedly altered in extensive inflammatory conditions. The increased concentration of galactose beta 1,3 GalNAc in CRS probably contributes to the high viscosity of the nasal mucus and interferes with normal mucociliary clearance. Exposed peripheral galactose residues may serve as attachment receptor sites for pathogenic bacteria. Means interfering with the ability of bacteria to adhere to specific receptors on host tissues warrant additional research.