Leukotriene D4 Nasal Provocation Test in Allergic Rhinitis

Leukotriene D4 Nasal Provocation Test: Rationale, Methodology, Diagnostic Value and Its Impact on Airway Inflammation in Allergic Rhinitis With or Without Asthma

Leukotrienes play critical roles in the inflammatory process in allergic rhinitis and bronchial asthma, therefore, anti-leukotriene therapy is part of treatment for asthma. However, not all allergic rhinitis accompanied with or without asthma treated with anti-leukotriene were effective. So it is critical to develop a method to identify the response subgroup. In this study, it is assumed that nasal physiological responsiveness to leukotriene nasal provocation test (NPT) is able to gain evidence on the effect of leukotriene on the development of allergic rhinitis and asthma, and is helpful to the use of anti-leukotriene agent. The purpose of the study is to establish the methodology and diagnostic value of leukotriene D4 (LTD4) nasal provocation.

Nasal provocation test induced by LTD4 will be conducted by measuring nasal airway resistance and airway symptoms in a stepwise concentration of LTD4 by nasal spray. Inflammation biomarkers, such as eosinophilic granulocyte in sputum and nasal lavage, fractional exhaled nitric oxide(FeNO), and lung function before and after nasal provocation will be studied to explore the impact of LTD4 nasal provocation test on airway inflammation.

Inclusion Criteria:

• Patients with allergic rhinitis accompanied with or without asthma
• positive skin prick test (SPT)
• had no acute upper or lower airway infection 2 weeks prior to study
• no oral or nasal anti-histamines
• no leukotriene receptor antagonists for 1 week
• no oral or nasal and inhaled corticosteroids for 2 weeks

Exclusion Criteria:

• smokers
• a past confirmed history of chronic respiratory disease other than asthma
• other severe systemic diseases (myocardial infarction, malignant tumor, etc.)
• under immunotherapy
• unable to complete the test or had limited understanding
• pregnancy