Biomarkers in therapy of allergic rhinitis
Currently, optional therapeutic measures for AR involve patient education, environmental control, pharmacotherapy, allergen immunotherapy (AIT), and surgery.90,91 Traditional medications include nasal corticosteroids, antihistamines, mast cell stabilizers, decongestants, etc. MP29-02, a combination of nasal corticosteroid and antihistamine, is a novel topical medication which has proved to be effective in reducing nasal hyperreactivity and nasal mediators such as substance P, in patients with AR.92As ILC2s have been shown to produce significant amounts of proinflammatory mediators in response to epithelium-derived cytokines80,81 and PGD2 and cysLTs82in AR patients, agents targeting the ILC2s and the mediators activating these cells have become targets for therapy. Rittchen and Heinemann have recently reviewed the central role of hematopoietic PGD2 synthase in allergic inflammation and indicated that PGD2 signaling might be a promising therapeutic target for AR, as PGD2 can activate Th2 cells, eosinophils and basophils.93 Indeed, a randomized controlled phase II clinical trial has recently demonstrated that ONO-4053, a novel prostaglandin D receptor 1 antagonist, was more effective than pranlukast, a leukotriene receptor antagonist, in treating patients with seasonal AR.94 Most recently, emerging studies have focused on biologics for treating allergic diseases; especially severe, uncontrolled asthma and AD, as well as AR.95,96 To date a high number of specific biologics targeting markers of Th1/2/17 inflammation have been introduced; with more under development.95,97 In particular, targeting IgE by omalizumab, a recombinant humanized anti-IgE antibody, has been shown to significantly improve symptoms in patients with inadequately controlled AR.98 Furthermore, combining omalizumab with sub-cutaneous immune therapy (SCIT) in patients with SAR and comorbid seasonal allergic asthma has been shown to lead to greater clinical improvements in AR and lung function than SCIT alone.99 Similarly, dupilumab, a biologic which targets IL-4Rα to block the activity of both IL-4 and IL-13, has been shown to provide nasal symptom relief in patients with uncontrolled asthma and comorbid AR.100