Role of Allergen Immunotherapy in Asthma Treatment and Asthma Development

Abstract

Allergen immunotherapy may modify the natural course of allergic diseases and induce remission. It includes subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT). For asthma, allergen immunotherapy using house dust mite (HDM) improves clinical symptoms and airway hyperresponsiveness and decreases drug requirements. Furthermore, it has been suggested that allergen immunotherapy also has the following effects: (1) the effect can be maintained for more than a year even if the treatment is terminated, (2) the remission rate of childhood asthma can be increased, (3) new allergen sensitization can be suppressed, and (4) asthma development can be prevented if allergen immunotherapy was performed in the case of pollinosis. Allergen immunotherapy differs from conventional drug therapy, in particular the effect of modifying the natural course of allergic diseases and the effect of controlling complicated allergic diseases such as rhinoconjunctivitis. The general indication for HDM-SCIT in asthma is HDM-sensitized atopic asthma with mild-to-moderate disease and normal respiratory function. HDM allergens should be involved in the pathogenesis of asthma, and a duration of illness of less than 10 years is desirable. HDM-SLIT is available for allergic rhinitis but not for asthma in Japan. However, as the efficacy of SLIT for asthma has been fully proven internationally, SLIT is also applied in asthmatics with complicated allergic rhinitis in Japan.

Clinical evaluation of rush immunotherapy using house dust mite allergen in Japanese asthmatics

“…Patients with HDM-sensitive bronchial asthma who had an indication for HDM-SCIT and agreed to receive rush-HDM-IT were recruited from the Allergy Center of Saitama Medical University to this study from August 2015 to December 2018. An indication for HDM-SCIT in atopic asthma was defined as mild-to-moderate persistent asthma with a percent predicted forced expiratory volume in 1 second (%FEV 1 ) of ≥70% [ 1 2 ]. Patients with HDM-sensitive bronchial asthma who did not agree to receive AIT were recruited as controls.…”

“…Allergen immunotherapy (AIT) is a treatment of administering increasing doses of clinically important allergens to patients who have allergic diseases [ 1 2 ]. The efficacy of treatment by AIT has already been established in allergic asthma, allergic rhinitis, and hymenoptera hypersensitivity [ 1 2 3 ]. In addition, AIT is the only existing treatment that can modify the pathological immune response underlying the allergic disease [ 1 2 ].…”

“…The efficacy of treatment by AIT has already been established in allergic asthma, allergic rhinitis, and hymenoptera hypersensitivity [ 1 2 3 ]. In addition, AIT is the only existing treatment that can modify the pathological immune response underlying the allergic disease [ 1 2 ]. AIT includes subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT).…”

Japanese cedar pollen upregulates the effector functions of eosinophils

“…Although the mechanisms that contribute to asthma exacerbation by JCP is still unknown, possible mechanisms have been suggested [ 8 ]. For example, orbicules (about 1 μm in size) on JCP can reach the airways and directly worsen the asthma control.…”

“…For example, orbicules (about 1 μm in size) on JCP can reach the airways and directly worsen the asthma control. Furthermore, nasal obstruction, local release of mediators in the upper airways, and systemic production of cytokines including type-2 cytokines may play roles in the JCP-induced asthma exacerbation [ 8 ]. In patients who are sensitized to JCP, exposure to JCP results in the aggravation of allergic diseases through the activation of mast cells or basophils by IgE crosslinking and the subsequent activation of T cells.…”