Clinical Efficacy and Safety of Sublingual Immunotherapy With Tree Pollen Extract in Children

Abstract

Valovirta E, Jacobsen L, Ljørring C, Koivikko A, Savolainen J. Allergy. 2006;61:1177–1183 PURPOSE OF THE STUDY. To investigate the clinical efficacy, safety, and dose-response relationship of sublingual immunotherapy (SLIT) in children suffering from rhinoconjunctivitis with or without asthma. STUDY POPULATION. Eighty-eight children (aged 5–15 years) in Finland with a history of tree-pollen–induced allergic rhinoconjunctivitis with or without seasonal asthma. Skin-prick test, specific immunoglobulin E, and conjunctival provocation test were used to confirm allergy to tree pollen. METHODS. Randomized, double-blind, placebo-controlled dose-response study using a glycerinated mixture of pollen from birch, hazel, and alder trees. Three groups receiving SLIT 5 days per week for up to 18 months were given an accumulated weekly dose of 24 000 U (dose group 1), an accumulated weekly dose of 200 000 U (dose group 2), or placebo. RESULTS. In the birch-pollen season, dose group 2 showed a significant reduction in both symptom (P = .01) and medication (P = .04) scores compared with those in the placebo group, but dose group 1 showed only a significant reduction of symptom scores (P = .03). No serious adverse events were reported. Oral local reactions were the most common adverse effect, ranging from 25% of patients in the placebo group to 50% in group 2. CONCLUSIONS. SLIT with tree-pollen extract provided dose-dependent benefits in tree-pollen–allergic children in terms of significantly reduced symptoms and medication use. The treatment was well tolerated. REVIEWER COMMENTS. The use of allergen-specific immunotherapy by the sublingual route, SLIT, has been increasing in clinical practice in Europe. SLIT is especially attractive for use in children, because it is a noninjection form of immunotherapy. This study showed a modest reduction (∼40%) in both symptom and medication scores. This is an interesting disease-modifying therapy that will need more studies to characterize efficacy and safety and to compare the results to that of subcutaneous immunotherapy before wider use can be recommended.