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 β-nerve growth factor (β-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 β-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 β-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 β-NGF+ mast cells/total mast cells and the ratio of β-NGF+ mast cells/total β-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 β-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.