A Prospective, Randomized, Double-blind, Placebo-Controlled Multi-centre Study on the Efficacy and Safety of Sublingual Immunotherapy (SLIT) in Children With Seasonal Allergic Rhinoconjunctivitis to Grass Pollen

Abstract

Purpose of the Study. Subcutaneous immunotherapy (SCIT) for seasonal allergic rhinitis is a well-established, effective, and potentially curative therapy. This study evaluated an alternate route for immunotherapy: the oral mucosa and gastrointestinal tract. Study Population. Ninety-seven children, aged 3 to 14 years, with seasonal allergic rhinitis and proven sensitivity to grass pollen were studied. Methods. Sensitivity to grass pollen was confirmed by positive skin-prick test, grass pollen–specific immunoglobulin E, and conjunctival provocation test. Patients were enrolled in a prospective, double-blind trial comparing sublingual immunotherapy (SLIT) to placebo. The treatment duration was 32 months. The primary outcome measure was the change in a multiple-symptom/medication score (which measured eye, nasal, and lung symptoms and rescue-medication use) after treatment. Data collected included patient-reported symptom scores and medication use, total and antigen-specific immunoglobulin E, skin-prick test, conjunctival provocation test, nasal provocation test, spirometry, exhaled nitric-oxide concentration, atopic dermatitis score, and eosinophilic cationic protein in nasal lavage fluid. Results. The multiple-symptom/medication score was significantly reduced by SLIT to 77.3% of the placebo group (P = .049). This overall score was affected mainly by a large reduction in rescue-medication usage among those in the treatment group (67% of placebo; P = .0025). There was no significant difference in any individual-symptom score. Conclusion. SLIT had a positive effect on rescue-medication usage but no significant effect on symptoms alone. Reviewer Comments. SLIT represents an alternative therapy with multiple potential advantages to SCIT, including the elimination of injections and improved safety profile. Several studies in adults and children have found improvement in symptom scores as well as reductions in medication use to the point where this is now being used in clinical practice in place of SCIT in many European countries. Additional studies, including investigation of optimal dosing and the potential to use multiple allergens, are needed to further define the future role of SLIT in the United States.