Local Effect of Neurotrophin-3 in Neuronal Inflammation of Allergic Rhinitis: Preliminary Report

Abstract

Background: Allergic rhinitis is a common inflamma-tory nasal mucosal disease characterized by sneezing, watery nasal discharge, nasal obstruction and itching. Although allergen-specific antibodies play a main role in the allergic airway inflammation, neuronal inflam-mation may also contribute to the symptoms of allergic rhinitis. Neuronal inflammation is primarily caused by the stimulation of sensory nerve endings with hista-mine. It has been shown that neurotrophins may also have a role in allergic reactions and neuronal inflam-mation. Nerve growth factor, neurotrophin 3 (NT-3), neurotrophin 4/5 and brain-derived neurotrophic fac-tor are members of the neurotrophin family. Although nerve growth factor and brain-derived neurotrophic factor are well studied in allergic rhinitis patients, the exact role of Neurotrophin-3 is not known.Aims: To investigate the possible roles of neurotroph-in-3 in allergic rhinitis patients.Study Design: Case-control study.Methods: Neurotrophin-3 levels were studied in the inferior turbinate and serum samples of 20 allergic rhi-nitis and 13 control patients. Neurotrophin-3 staining of nasal tissues was evaluated by immunohistochemis-try and ELISA was used for the determination of serum Neurotrophin-3 levels.Results: Neurotrophin-3 staining scores were statis-tically higher in the study group than in the control patients (p=0.001). Regarding serum Neurotrophin-3 levels, no statistically significant difference could be determined between allergic rhinitis and control pa-tients (p=0.156). When comparing the serum NT-3 levels with tissue staining scores, there were no sta-tistically significant differences in the allergic rhinitis and control groups (p=0.254 for allergic rhinitis and p=0.624 for control groups).Conclusion: We suggest that Neurotrophin-3 might af-fect the nasal mucosa locally without being released into the systemic circulation in allergic rhinitis patients