Phenotypic alteration of neuropeptide-containing nerve fibres in seasonal intermittent allergic rhinitis.

BACKGROUND: Allergic rhinitis (AR) is the most common allergic disease affecting the respiratory tract. Next to inflammatory changes, the airway innervation plays an important modulatory role in the pathogenesis of the disease. OBJECTIVE: To examine the participation of different neuropeptides in the human nasal mucosa of intermittent (seasonal) AR tissues in the allergic season. METHODS: Immunohistochemistry for substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP) and neuropeptide tyrosine (NPY) was related to the characterization of inflammatory cells in tissues of patients with seasonal AR (n=18). RESULTS: While there was a significant increase in the number of eosinophils present if compared with a control group, no changes occurred in mast cell numbers. Immunostaining was abundantly found in different nerve fibre populations of both groups. SP expression was significantly increased in mucosal nerve fibres of patients with intermittent (seasonal) AR. Also, significantly increased numbers of VIP- and NPY-immunoreactive nerve fibres were found in biopsies of rhinitis patients in comparison with sections of normal human nasal mucosa. In contrast, CGRP expression did not change significantly. CONCLUSION: The increase of neuropeptide expression in mucosal nerve fibres indicates a major role of the autonomous mucosal innervation in the pathophysiology of intermittent (seasonal) AR.

Aspirin-sensitive rhinitis-associated changes in upper airway innervation.

Aspirin-sensitive rhinitis is the manifestation of aspirin intolerance in the upper respiratory tract. The disease represents a pseudoallergy against aspirin or related nonsteroidal anti-inflammatory drugs. As a major immunomodulatory role for airway innervation has been proposed in airway inflammatory diseases, the present study assessed changes in human nasal mucosa innervation in patients with aspirin-sensitive rhinitis in comparison to a control group. Immunohistochemistry for protein gene product 9.5, tachykinins, calcitonin gene-related peptide, vasoactive intestinal peptide (VIP) and neuropeptide tyrosine was performed on cryostats sections of nasal mucosa and neuropeptide containing nerves were examined independently using a score grading. In comparison to the control, the aspirin-sensitive rhinitis group had a significant increase of VIP-like immunoreactivity in mucosal nerve fibres. In contrast to constant numbers of mast cells, highly significant increases in the numbers of eosinophils were found in the group of aspirin-sensitive rhinitis patients. In summary, the present quantification of neuropeptide-immunoreactivity of mucosal nerves demonstrated differences in the human nasal mucosa innervation between nonrhinitic and aspirin-sensitive rhinitic individuals. These differences may reflect a pathophysiological role of upper airway innervation in pseudoallergic reactions.

Legal liability and orthopedic surgery.

Civil Liability and the Investigational Device Exemptions.