A Three-Year Course of House Dust Mite Sublingual Immunotherapy Appears Effective in Controlling the Symptoms of Allergic Rhinitis

IR (index of reactivity)-house dust mite sublingual immunotherapy liquid formulation for allergic rhinoconjunctivitis: Systematic review and meta-analysis of randomized and nonrandomized studies

Background

Although randomized controlled trials (RCT) are the reference standard of evidence in allergen immunotherapy (AIT), nonrandomized studies (NRS) are needed to confirm their results in more representative populations, particularly for treatment duration and persistence. However, when discrepancies are observed between RCT and NRS, NRS reliability decreases because these discrepant results are generally attributed to the methodologic flaws of NRS.

Objective

We compared the benefit of sublingual AIT (SLIT) for allergic rhinoconjunctivitis in NRS versus RCT focusing on a single product/allergen to reduce heterogeneity.

Methods

For meta-analysis, house dust mite (HDM) SLIT liquid formulation studies were sourced from computerized (Medline, Web of Science, and LILACS databases, to January 2023) and manual literature searches. Populations, treatments, and outcome data were combined (DerSimonian-Laird method). Noncomparative NRS were compared to RCT' SLIT arm before and after treatment. Efficacy was determined as the standardized mean difference (SMD) in symptom score (SS) and medication score (MS).

Results

Data from 12 NRS (682 patients) and 8 RCT (176 patients) were analyzed. The benefit with index of reactivity (IR)-HDM SLIT liquid formulation was found significant for, first, SS in both NRS (SMD = -1.27; 95% confidence interval [CI], -1.64, -0.90) and RCT (SMD = -0.56; 95% CI, -0.90, -0.21), and second, MS with SMD equal to -1.35 (95% CI, -1.77, -0.93) and -0.46 (95% CI, -0.67, -0.25), respectively. Metaregression showed that symptom improvement was correlated with treatment duration with consistent results in NRS and RCT with 12-month SS data: -0.87 (interquartile range, -1.02, -0.77) and -0.75 (interquartile range, -0.93, -0.41), respectively.

Conclusion

This meta-analysis showed comparable clinical benefit of IR-HDM SLIT liquid formulation increasing over time in both NRS and RCT, suggesting that NRS may reliably integrate RCT results and be considered for guidelines.

Evaluation of the quality of guidelines for sublingual immunotherapy of allergic rhinitis

BACKGROUND

Guidelines are intended to facilitate evidence-based clinical decision-making and knowledge translation; however, the quality and rigor of the guidelines are different. This study was conducted to assess the quality of sublingual immunotherapy guidelines for allergic rhinitis, in order to provide a reference for evidence-based clinical treatment and management of sublingual immunotherapy.

METHODS

Using both Chinese and English search methods, articles were obtained from PubMed, Cochrane, Web of Science, CNKI, CBM, WanFang Data, VIP, and other databases from the construction of the database to September 2020. The AGREE II instrument was used by two researchers to independently evaluate the quality of the extracted articles, and the consistency of the researchers was evaluated using the inter-group correlation coefficient.

RESULTS

Ten articles were included in this study, of which two articles ranked A level, six articles ranked B level, and two articles ranked C level. The six sections of AGREE II included scope and aim, clarity, participant, applicability, rigor, and editorial independence, with standardized scores of 78.06%, 45.83%, 42.81%, 77.50%, 50.42%, and 46.25%, respectively.

CONCLUSION

The quality of the current guidelines for sublingual immunotherapy is average. The formulation methodology and reporting standards of these guidelines must be developed. By standardizing the treatment of sublingual immunotherapy properly, it is recommended that guideline makers refer to the AGREE II to formulate high-quality guidelines and promote their wide application.