Bufe A, Ziegler-Kirbach E, Stoeckmann E, et al. Allergy. 2004;59:498–504
Purpose of the Study.
To determine the clinical efficacy of high-dose sublingual immunotherapy (SLIT) in children with grass-pollen allergy by using a double-blind placebo-controlled study.
A total of 161 children with seasonal rhinoconjunctivitis, 82 in the treatment group and 79 in the placebo group, were enrolled from 33 centers in Germany.
For the first year, patients were given either treatment or placebo; for the remaining 2 years, all patients were given treatment in an open-controlled manner. Symptom scores and medication usage were assessed during the pollen seasons and combined to determine a clinical index (CI), the primary end point of the study. Titrated skin-prick tests and specific IgE and IgG subclass antibodies were measured each year.
A total of 132 patients completed the study. Analysis after 1 year of SLIT and analysis of the change in CIs during the 3 grass-pollen seasons showed that there was no significant difference in the CIs between the treatment and placebo groups. However, subgroup analysis in a repeated-measures model revealed that patients with SLIT and severe symptoms before beginning treatment showed a 30% improvement after 3 years, compared with 10% improvement in the placebo group. Allergen-specific IgE and IgG subclass antibodies increased in both the treatment and placebo groups.
Efficacy of SLIT could only be seen in children with severe clinical symptoms after 3 years of therapy. There was also a significant placebo effect.
SLIT is readily given to allergic patients in European countries, but its use in the United States is limited. SLIT use in children is an attractive alternative to subcutaneous injections, given its lack of pain and decreased chance of systemic adverse effects. Although early controlled studies analyzing SLIT did not demonstrate clear clinical effects, SLIT has proved to have some reproducible value in adults, and a small number of other studies have also shown it to be effective in children. Only additional long-term comparative studies will show whether SLIT can compete with the established subcutaneous treatment.