Sublingual Immunotherapy Tablets Relieve Symptoms in Adults with Allergic Rhinitis: A Meta-analysis of Randomized Clinical Trials

BACKGROUND: Sublingual immunotherapy (SLIT) has been proven to be effective against house dust mite-induced allergic rhinitis. However, the efficacy in adults with allergic rhinitis has never been reported on SLIT tablets. The current meta-analysis aimed to illustrate the differentiated efficacy of SLIT tablets on allergic rhinitis. METHODS: Our systematic review and meta-analysis were performed on allergic rhinitis patients and aimed to summarize those randomized controlled studies (RCTs). PubMed, EMBASE, Cochrane library, and MEDLINE were screened for associated articles. We included RCTs on allergic rhinitis patients undergoing SLIT therapy and reporting outcomes on symptom relief and serum-specific IgE levels. The effect of SLIT tablets on the Rhinitis Quality Life Questionnaire Score (RQLQ), Rhinitis Total Symptom Score (RTSS), and serum-specific IgE levels was evaluated using RevMan 5.3. RESULTS: Seven studies were included, with 2723 patients identified. All of the studies were RCT. The included seven studies were all conducted on adults. Among the included seven articles, five researches administered patients with SLIT tablets and were eligible for meta-analysis of RTSS, consisting of 1490 patients. Overall, RTSS was significantly reduced in the SLIT tablet group compared with that in the placebo group (standard mean difference = −0.33, 95% confidence interval [−0.54, −0.13], P < 0.01). There was no significant difference in specific IgE levels between SLIT and placebo patients. CONCLUSIONS: SLIT tablets effectively relieve rhinitis symptoms in adults with allergic rhinitis. Nevertheless, the current evidence may be limited due to sample size and the heterogeneity between studies. Large sample size and multiple center RCTs on the efficacy of different formulations of SLIT drugs are still needed to provide further evidence and a more precise recommendation.