Moller C, Dreborg S, Ferdousi HA, et al. J Allergy Clin Immunol. 2002;109:251–256
Purpose of the Study.
To determine if specific immunotherapy can prevent the development of asthma and reduce bronchial hyperresponsiveness in children with seasonal allergic rhinoconjunctivitis.
A total of 205 children, 6 to 14 years old, from 6 European pediatric centers were enrolled from 1992–1994. All children had a clinical history of moderate-to-severe rhinoconjunctivitis caused by birch and/or grass pollen allergy, as well as positive skin testing and a conjunctival provocation test to birch and/or grass pollen. At enrollment, none had asthma requiring daily controller therapy. Patients were randomized to 1) active treatment group receiving specific immunotherapy (SIT) to birch and/or grass pollen for 3 years or 2) an observational control group. Symptomatic treatment was limited to loratadine, levocabastine, sodium cromoglycate, and nasal budesonide. Patients were evaluated based on the following: 1) asthma diagnosis, symptoms, and peak flow; 2) methacholine provocation during the pollen season(s) and winter; and 3) visual analog scale (VAS) for rhinoconjunctivitis after every season.
Of the 205 patients, 43 were allergic to birch, 124 were allergic to grass, and 41 were allergic to both. Ninety-seven children received SIT while 94 served as controls. At study enrollment, 40 (20%) children had mild seasonal asthma symptoms despite negative histories of asthma. After 3 years, 38 of 40 with asthma still had symptoms. Among those with asthma, the SIT group had fewer asthma symptoms after 3 years of therapy as evaluated by clinical diagnosis (odds ratio: 2.52; P < .05). Bronchial hyperresponsiveness was significantly reduced in the SIT group, both in and out of season, when compared with controls (P < .05). Of nonasthmatics, asthma developed in 19 of 79 in SIT group and 32 of 72 controls. Children receiving SIT had improved VAS scores for conjunctivitis (P < .001) and rhinitis (P < .01).
This study indicates that specific immunotherapy for seasonal rhinoconjunctivitis can reduce development of asthma. The authors also demonstrate a reduction in symptom profiles and medication usage in the active treatment group.
Allergic rhinitis is a known risk factor for the development of asthma. Additionally, other investigators have demonstrated a link between upper airway disease and bronchial hyperresponsiveness. This study profiles a group of children with clinically relevant seasonal rhinoconjunctivitis and suggests that specific immunotherapy may have a role preventing the development of asthma. This study challenges clinicians to evaluate children with significant upper airway disease and consider the benefits of allergen immunotherapy. Additional work is needed to further define the role of allergen immunotherapy in the prevention of asthma development in children with both seasonal and perennial disease. Additionally, this study highlights the importance of surveillance for asthma symptoms in children with allergic rhinoconjunctivitis.