The contribution of sublingual immunotherapy to the achievement of control in birch-related mild persistent asthma: a real-life randomised trial

Abstract

Background: Asthma control represents the main goal of asthma management and different strategies aim to avoid the long term downsides of inhaled corticosteroids. We investigated in real-life conditions the contribution of sublingual immunotherapy in achieving the control of birch-related mild persistent asthma compared to two usual step-up therapeutic options.

Methods: A three-year open randomised study included 84 asthmatics, uncontrolled during the previous birch pollen season, despite a treatment with budesonide 400μg/day. Patients randomly received budesonide 800μg/day, budesonide 1600μg/day, budesonide 400μg/day plus montelukast 10μg/day and budesonide 400μg/day plus carbamylated allergoid of betulaceae pre-coseasonally. Asthma Control test, combined allergy symptoms and medications score, albuterol consumption, lung function, nasal eosinophils and nasal steroids usage were assessed as changes from the first to last pollen season.

Result: Seventy-six patients concluded the study. All options, except budesonide 800μg/day, produced an improvement of mean monthly Asthma Control test (p<0.05). Patients undergoing low-dose budesonide plus immunotherapy achieved, after three years, an appreciable control (ACT mean score 24). A significant improvement was seen in all groups for allergy symptoms plus medications and bronchial reactivity. Albuterol consumption and lung function improved in all but the first group. Only budesonide plus immunotherapy reduced nasal eosinophils and nasal steroids usage. Two mild self-resolving adverse events were reported.

Conclusions: For patients with respiratory allergy due to birch pollen and mild persistent asthma, sublingual immunotherapy added to low-dose inhaled corticosteroids appears effective in maintaining long-term seasonal asthma control, representing a safe opportunity to reduce the cumulative amount of delivered corticosteroids.

Keywords: Antileukotrienes; Asthma control; Birch allergy; Inhaled corticosteroids; Monomeric carbamylated allergoid; Real life trial; Rhinoconjunctivitis; SLIT; Sublingual immunotherapy.