[Ultrastructural changes in allergic rhinitis vs. idiopathic rhinitis]

Nasal hyperreactivity is one of the most important underlying mechanisms in allergic rhinitis (AR) as well as idiopathic rhinitis (IR). The aim of the present study was to examine pathomorphological changes in nasal mucosa in these subgroups of rhinitis.

Tissue samples of human inferior turbinates from 20 patients with AR and 16 patients with IR were taken during nasal surgery and preserved in glutaraldehyde or paraformaldehyde. Ultrathin sections of specimens from 15 patients without chronic inflammation of nasal mucosa were used as controls. Primary antibodies against substance P (SP), calcitonin-gene-related peptide (CGRP), and endothelial nitric oxide synthase (NOS III) were applied, and the immunocomplexes were visualized by an immunocytochemical staining technique using gold-labeled antibodies. Immunostained structures were photodocumented using light and transmission electron microscopy.

The nasal mucosa of patients with AR and IR showed similarities on the ultrastructural level. A strong innervation pattern with sensory nerve fibers containing SP and CGRP demonstrated neurogenic inflammation. Extensive edema and cellular infiltrations were found in AR. A decreased presence of eosinophils and nitric oxide was observed in IR.

On the ultrastructural level, AR and IR showed many similarities but also some differences. Based on these findings, anti-inflammatory therapy could be recommended for both types of rhinitis.