The Cysteinyl Leukotriene (CysLT) Pathway in Allergic Rhinitis

The cysteinyl leukotrienes (CysLTs), leukotriene C4(LTC4), leukotriene D4(LTD4) and leukotriene E4(LTE4) are released in response to specific allergen in nasal secretions from patients with active allergic rhinitis. The symptoms and inflammation of allergic rhinitis can be induced by inhalation of CysLTs. Inflammatory cells from patients with allergic rhinitis express both the synthetic and signaling proteins for the CysLT pathway. CysLTs activate cell migration, in particular eosinophils, endothelial or epithelial cell adhesion and release of cytokines and other oxidative inflammatory mediators. Cytokines may also activate the release of CysLTs from eosinophils and other myeloid cells and also enhance the expression of the CysLT1 receptor creating an inflammatory amplification cycle. Systemic CysLT1 receptor antagonists can reduce the inflammation and symptoms of both allergic rhinitis and asthma.