title: Effects of leukotriene D4nasal challenge on bronchial responsiveness and inflammation in asthmatic patients with allergic rhinitis.
abstract: BACKGROUND
  In asthmatic patients with allergic rhinitis (AR), increased cysteinyl leukotrienes (CysLTs) production in the secretion of nasal mucosa has been associated with greater bronchial hyperresponsiveness (BHR) after nasal allergen challenge. However, the role of CysLTs in eliciting BHR after nasal allergen challenge has not been evaluated. The aim of this study is to evaluate the effect of LTD4nasal challenge on BHR and inflammation in asthmatic patients with AR.
  
  
  METHODS
  In this self-controlled study, fifteen eligible consecutively recruited subjects underwent methacholine (Mch) bronchial provocation test before and 30 minutes after LTD4nasal provocation test. The cumulative concentration of LTD4inducing a 60% increase in nasal airway resistance (PC60NAR) was calculated. The mean values of cumulative doses inducing a 20% decrease in forced expiratory flow in one second (PD20FEV1) for Mch before and after nasal challenge were compared. Fractional exhaled nitric oxide (FeNO), differential inflammatory cell counts in nasal lavage and induced sputum before and after nasal challenge were compared.
  
  
  RESULTS
  House dust mites were the major allergens accounting for 10/15 (66.7%) of asthmatic patients with AR. The PC60NAR for LT was (8.39±3.48)×10-3mg·mL-1. The PD20FEV1before and after nasal challenge was 3.05±3.81 and 2.70±3.81 µmol, respectively (P=0.45). The percentages of eosinophils were (38.36±23.14)% and (45.70±24.86)% in nasal lavage, and (17.51±11.05)% and (24.29±16.52)% in induced sputum before and 24 hours after nasal challenge. The neutrophil counts were (60.64±23.14)% and (53.30±24.46)% in nasal lavage, and (53.83±23.27)% and (56.19±22.28)% in induced sputum before and 24 hours after nasal challenge. The values of FeNO were 40 [35] and 43 [30] ppb before and 24 hours after nasal challenge. No severe adverse effects were reported during the tests.
  
  
  CONCLUSIONS
  Although most asthmatic patients with AR were sensitive to LTD4nasal challenge, LTD4nasal provocation tests do not confer any major effect on BHR. LTD4might not play a vital role in eliciting bronchial responsiveness induced by nasal allergen challenge.
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China.
authors.forename: Yanqing
authors.initials: Y
authors.lastname: Xie
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China.
authors.forename: Weijie
authors.initials: W
authors.lastname: Guan
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China.
authors.forename: Rongquan
authors.initials: R
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China.
authors.forename: Shu
authors.initials: S
authors.lastname: Xia
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China.
authors.forename: Wenhua
authors.initials: W
authors.lastname: Jian
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China.
authors.forename: Zhiyu
authors.initials: Z
authors.lastname: Liang
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China.
authors.forename: Jinping
authors.initials: J
authors.lastname: Zheng
keywords: Leukotriene D4 (LTD4); airway hyperresponsiveness; allergic rhinitis (AR); asthma; bronchial provocation