Efficacy of Subcutaneous and Sublingual Immunotherapy for House Dust Mite Allergy: A Network Meta-Analysis–Based Comparison

Background Meta-analyses comparing the efficacy of sublingual immunotherapy (SLIT) and subcutaneous immunotherapy (SCIT) for house dust mite allergy are lacking. Objective To compare the efficacy of SLIT drops, SLIT tablets, and SCIT in patients with perennial allergic rhinitis through network analysis. Methods Frequentist network meta-analyses estimated the standardized mean difference (SMD) across the three immunotherapy modalities on allergic rhinitis symptom and medication score data from double-blind randomized clinical trials. Random effects models were investigated. Results We included 26 double-blind randomized clinical trials in this meta-analysis for the symptom score and 18 for the medication score. In the direct pairwise meta-analysis, a significant reduction of the symptom score was observed for all immunotherapy modalities compared with the placebo: pooled SMDs of –0.461 (95% confidence interval [CI], –0.795 to –0.127) for SLIT drop, –0.329 (95% CI, –0.426 to –0.231) for SLIT tablet, and –1.669 (95% CI, –2.753 to –0.585) for SCIT. For the medication score, a significant reduction was observed for all modalities. In network meta-analysis, the clinical efficacy of SCIT based on the symptom score was greater than for SLIT drop or SLIT tablet (SMD: –0.697, 95% CI, –1.105 to –0.288; and SMD: –0.819, 95% CI, –1.242 to –0.397). However, there was no significant difference in the symptom score between SLIT drop and SLIT tablet. Conclusions This study demonstrated the clinical efficacy of all house dust mite immunotherapy modalities and suggests that SCIT may be more effective than SLIT drops or tablets in controlling symptoms of allergic rhinitis.