Grass Pollen Immunotherapy as an Effective Therapy for Childhood Seasonal Allergic Asthma

Abstract

Roberts G, Hurley C, Turcanu V, Lack G. J Allergy Clin Immunol. 2006;117:263–268 PURPOSE OF THE STUDY. There is abundant evidence to support the use of specific immunotherapy (SIT) in the treatment of allergic rhinoconjunctivitis. Studies that have looked at the role of SIT for the treatment of seasonal allergic asthma are lacking. This study evaluated the safety and effectiveness of SIT for the treatment of seasonal allergic asthma in children. STUDY POPULATION. A total of 39 of 161 screened subjects 3 to 16 years old were enrolled onto the study from the allergy clinic at St Mary's Hospital (London, United Kingdom). All of them had history of grass-pollen–induced asthma that required 200 μg of inhaled beclomethasone (or equivalent) daily. All subjects had a positive skin-prick–test response: a positive specific immunoglobulin E level (Pharmacia CAP) to a relevant grass pollen (Phleum pratense). Subjects also had a positive conjunctival provocation test. Subjects were excluded if they previously had been treated with grass-pollen immunotherapy or had a history of perennial asthma requiring inhaled corticosteroids, significant perennial allergic rhinitis, or sensitization to a pet present in the household. METHODS. The study was a single-center, randomized, double-blind, placebo-controlled study over 2 successive pollen seasons. Subjects were randomly assigned to receive SIT or placebo. The primary outcome was the asthma-symptom–medication score during the second pollen season. Secondary outcome measures included lung function, cutaneous, conjunctival, and bronchial allergen reactivity, and both exhaled nitric oxide and sputum eosinophil levels. RESULTS. The use of SIT was associated with a substantial reduction in asthma-symptom–medication score as compared with placebo (P = .04). There was significant reduction in cutaneous (P = .002), conjunctival (P = .02), and bronchial (P = .01) reactivity to allergen after SIT compared with placebo. Children in the 2 groups had similar levels of airway inflammation, although less inhaled steroids were required for those in the active group. No serious adverse events were reported, and no subjects withdrew because of adverse events. CONCLUSIONS. SIT is effective and well tolerated in children with seasonal allergic asthma to grass pollen. REVIEWER COMMENTS. There are limited studies that have demonstrated the efficacy of immunotherapy for treatment of asthma. On the basis of the complex nature of asthma and realizing that multiple phenotypes exist, it is understandable that there is difficulty in evaluating SIT for asthma. This study provided encouraging evidence for the role of SIT in the treatment of seasonal allergic asthma. Unfortunately, the majority of allergic patients are sensitized to multiple allergens, and symptoms are typically triggered by several different allergens.