Enhanced nerve growth factor expression by mast cells does not differ significantly between idiopathic and allergic rhinitis.

ABSTRACT

BACKGROUND: The role of neurotrophins in allergic rhinitis (AR) has been well studied, but it has not been evaluated in idiopathic rhinitis (IR). OBJECTIVE: We aimed to evaluate the nasal ß-nerve growth factor (ß-NGF) expressions of mast cells in patients with AR and IR. METHODS: Seventeen patients with house dust mites-induced persistent moderate/severe allergic rhinitis (mean age 29.7 ± 11.96), 14 patients with idiopathic rhinitis (mean age, 29.3 ± 10.62), and 16 healthy controls (29.9 ± 11.57) were included in the study. Nasal biopsy specimens were taken from the posterior part of the inferior turbinate from all of the study subjects. Nasal ß-nerve growth factor and its receptors, pan-neurotrophin receptor p75, and tyrosine kinase A (trkA) were assessed with an immunofluorescence assay. Mast cells were determined by both an immunofluorescence assay and immunohistochemistry as tryptase-positive cells. RESULTS: The ß-NGF, trkA, and p75 receptor counts were significantly higher in AR and IR patients than in the control group (P < .001, for each), but they were not different between AR and IR patients. Similarly, the ratio of ß-NGF+ mast cells/total mast cells and the ratio of ß-NGF+ mast cells/total ß-NGF+ cells in AR and IR patients was found to be elevated when compared with the control group (P < .001, P < .001, P < .001, and P = .046, respectively); furthermore, the 2 ratios were not statistically different between the 2 patient groups. CONCLUSION: The increase in ß-NGF-expressing mast cells does not differ between idiopathic and allergic rhinitis. Therefore, we propose that mast cells do play a role in the pathogenesis of IR as important as in that of AR.