Thymic stromal lymphopoietin expression is increased in nasal epithelial cells of patients with mugwort pollen sensitive-seasonal allergic rhinitis

Background Excessive expression of thymic stromal lymphopoietin （TSLP） has been demonstrated in asthmatic airway epithelia and in nasal epithelia from animal models of allergic rhinitis （AR）, but the evidence of expression of TSLP in nasal epithelial cells （NECs） of patients with AR is lacking. We aimed to investigate the expression of TSLP in NECs of patients with mugwort sensitive-seasonal AR and determine whether it is associated with severity of symptoms and the number of infiltrated eosinophils in nasal mucosa. Methods NECs specimens were obtained by scraping with plastic curettes from the nasal inferior turbinates of patients with mugwort pollen sensitive-seasonal AR （n=22） and nonallergic controls （n=11） during last peak mugwort pollen season. The severity of nasal symptom was assessed using a Visual Analog Scale （VAS）. In addition, serum mugwort pollen IgE levels were tested from each patient. In situ hybridization （ISH） was performed to test the messenger RNA （mRNA） of TSLP in the NECs. Furthermore, immunohistochemical staining （IHC） was scored to evaluate the expression of TSLP and eosinophil cell count was made by May-Grunwald/Giemsa staining. The correlation between expression of TSLP and all other parameters was analyzed in this study. Results The mRNA level of TSLP was significantly increased in NECs of patients with AR compared with the nonallergic control group （P 〈0.05）. In addition, IHC results showed that expression of TSLP in NECs from patients with AR was up-regulated which was correlated with VAS score （r=0.598; P 〈0.05） and nasal eosinophils count （r=0.702; P 〈0.05）, but it was unrelated with mugwort pollen specific IgE level. Conclusions These preliminary findings indicate a potential relationship between TSLP expression, severity of symptoms and nasal eosinophils count in pathogenesis of AR, but TSLP expression did not correlate with mugwort pollen specific IgE level. The elevated expression of TSLP might play a critical role in local atopical responses of AR. In the future, the TSLP has the potential to be one of the most important molecular markers for AR diagnoses and assessment.