Remodelling of nasal mucosa in mild and severe persistent allergic rhinitis with special reference to the distribution of collagen, proteoglycans, and lymphatic vessels

Background Small leucine-rich repeat proteoglycans (decorin, biglycan, and lumican), collagen, and lymphangiogenesis are involved in tissue remodelling of various organs with inflammatory diseases.Objective We determined the expression level and the distribution pattern of small leucine-rich repeat proteoglycans (decorin, biglycan, and lumican), collagen and lymphatic vessels in healthy, mild, and severe persistent allergic nasal mucosa.Methods The distribution pattern of collagen, proteoglycans, and lymphatic vessels in healthy, mild, and severe persistent allergic nasal mucosa was evaluated by the van Gieson staining, immunohistochemistry, RT-PCR, and Western blotting. Quantitative analyses of collagen deposition were calculated as the median of the total percentage area in the tissue specimen. For the evaluation of proteoglycans, the percentage area stained and median optical density were measured for each image. Lymphatic vessels were identified by D2-40 antibody and calculated using the lymphatic vessel density and endothelial length density in tissue specimens. The expression of MMP 2 and 9, TIMP1 and 2 was evaluated with RT-PCR and Western blotting.Results In mild and severe persistent allergic nasal mucosa, compared with healthy nasal mucosa, collagen showed more intense staining in the superficial and submucosal layer. In healthy and allergic nasal mucosa, decorin was lightly stained without significant differences in the percentage area and optical density of staining. However, lumican and biglycan showed strong immunoreactivity in mild and severe persistent allergic nasal mucosa, which was verified by Western blotting. The number and endothelial length density of lymphatic vessels were increased in mild and severe persistent allergic nasal mucosa compared with healthy nasal mucosa. The expression of MMP 9 was increased in severe persistent allergic rhinitis.Conclusion and Clinical Relevance These results suggest that the altered distribution pattern of collagen, proteoglycans, and lymphatic vessels could potentially modulate the remodelling of nasal mucosa in mild and severe persistent allergic nasal mucosa.