Interleukin-17 producing T cells could be a marker for patients with allergic rhinitis.

BACKGROUND: Interleukin-17A (I-17A)-producing CD4+T helper cells have been implicated in allergic inflammation; however, the role of IL-17A in allergic rhinitis (AR) patients with different degrees of atopy and airway reactivity to methacholine (Mch) has not been examined. OBJECTIVES: To explore IL-17A-producing CD3+CD4+T cells in peripheral blood of patients with persistent AR and assess the degree of atopy, eosinophil count (Eo count), and bronchial hyper-responsiveness (BHR) to methacholine. METHODS: The study involved 61 patients and 30 controls. The percentage of CD3+CD4+IL-17A+T cells in peripheral blood was measured by flow cytometry, bronchial challenges with Mch were performed, as were skin prick tests with standard inhalant allergens, and Eo count was measured. Atopic status was determined by the number of positive SPT results and wheal mean diameter. RESULTS: A statistically significant difference in Th17 cell percentage was found in the AR and control groups (2.59 +/- 1.32% and 1.24 +/- 0.22% respectively, P = 0.001). Forty-one patients (67.2%) were polysensitized to indoor and outdoor allergens, while 20 (32.8%) had positive skin prick tests to indoor allergens. CD4+T cells were significantly higher in the patient group compared to the control group (2.91 +/- 1.5% versus 1.91 +/- 0.62%, P = 0.005), as was Eo count (4.48 +/- 2.13 vs. 2.32 +/- 1.83) (P = 0.0001). Forty-one in the AR group (67%) and 7 (23%) in the control group were Mch-positive (P = 0.001). The percentage of IL-17A-producing CD4+T cells was significantly higher in males compared to females (3.15 +/- 1.8% versus 2.31 +/- 0.9%, P = 0.02) CONCLUSIONS: Polysensitized AR patients exhibited higher IL-17A-producing CD4+T cell levels and eosinophil counts. Male patients displayed a higher frequency of IL-17A-producing T cells.

IL-17 producing T cells correlate with polysensitization but not with bronchial hyperresponsiveness in patients with allergic rhinitis.

BACKGROUND: Th2-type T cell response has a considerable role in atopic diseases. The involvement of Th17 and IL-17 in atopy process provided new understanding of allergic diseases. Bronchial hyperresponsiveness is quite common in allergic rhinitis. We aimed to explore the expression of IL-17 producing CD3+ CD4+ T cells in peripheral blood of rhinitic patients, with/without bronchial hyperresponsiveness and sensitized to common allergens, as this relationship has not been examined. METHODS: Sixty one patients with allergic rhinitis and thirty controls were examined. IL-17 producing T cells were detected by flow cytometry, IL-17, IL-4 and IL-13 levels in peripheral blood were evaluated by ELISA. Bronchial hyperresponsiveness was investigated with methacholine challenge test. Atopy was evaluated by skin prick tests with common allergens. RESULTS: IL-17 producing T cell percentage of AR group was significantly higher: 2.59 ± 1.32 than in controls 1.24 ± 0.22, (p = 0.001). Significant sex related difference in CD3+ CD4+ IL-17 T cells was observed: respectively in male patients versus female 3.15 ± 1.8% and 2.31 ± 0.9%, (p = 0.02). Rhinitics had greater bronchodilator responses compared to controls (p = 0.001), however the percentages of T cells in both groups appeared equal. Serum IL-17 levels in AR group were significantly higher (5.10 ± 4.40) pg/ml than in controls (3.46 ±1.28) pg/ml, (p = 0.04). IL-4 levels (0.88 ± 1.27) and IL-13 levels (3.14 ± 5.85) in patients were significantly higher than in control's (0.54 ± 0.10) pg/ml, (p = 0.001) and (1.19 ± 0.64) pg/ml; (p = 0.001) respectively.The percentages of T cells in patients sensitized to 5 allergens (group I) were significantly lower (1.91 ± 0.62) than those sensitized to more than 5 allergens (group II) (2.91 ± 1.5) (p = 0.004). CONCLUSIONS: The observed higher levels of IL-17 producing T cells in polysensitized males suggest a role of IL-17 in pathogenesis of AR. The higher airway responsiveness in AR may not be Th17 dependent. The higher serum values of IL-17, IL-4 and IL-13 demonstrate the presence of cytokine balance in atopic diseases.