Metaanalysis of the efficacy of sublingual immunotherapy in the treatment of allergic asthma in pediatric patients, 3 to 18 years of age

Background: Recent studies have documented the efficacy and safety of sublingual immunotherapy (SLIT) in patients with rhinitis, but the value of this treatment in those with asthma is still debated. We evaluated the efficacy of SLIT in the treatment of allergic asthma in children by a metaanalysis of randomized, double-blind, and placebo-controlled (DBPC) clinical trials. Methods: Electronic databases were searched up to May 31, 2006, for randomized DBPC trials assessing SLIT in pediatric cases of asthma. Effects on primary outcomes (ie, symptom scores and concomitant use of rescue medication) were calculated with standardized mean differences (SMDs) using the random-effects model. We performed the metaanalysis using a statistical software package (RevMan, 4.2.8; The Cochrane Collaboration; Oxford, UK), and we followed the recommendations of the Cochrane Collaboration and the Quality of Reporting of Metaanalyses guidelines. Results: Seventy-three articles were identified and reviewed. Nine studies, all published after 1990, fulfilled the selection criteria. A total of 441 patients had a final assessment and were included in the analysis. Two hundred thirty-two patients received SLIT, and 209 patients received placebo. The results of the present analysis demonstrated a relevant heterogeneity due to widely differing scoring systems. Overall, there was a significant reduction in both symptoms (SMD 1.14; 95% confidence interval [CI], -2.10 to -0.18; p = 0.02) and medication use (SMD, 1.63; 95% CI, -2.83 to -0.44; p = 0.007) following SLIT. Conclusion: SLIT with standardized extracts reduces both symptom scores and rescue medication use in children with allergic asthma compared with placebo.