Efficacy of add-on sublingual immunotherapy for adults with asthma: A meta-analysis and systematic review

Efficacy of Sublingual Immunotherapy in Allergic Rhinitis Patients with Asthma: A Systematic Review and Meta-Analysis

OBJECTIVE

Sublingual immunotherapy (SLIT) has been widely applied to treat patients with allergic rhinitis (AR). However, meta-analyses on the efficacy of SLIT in AR patients with asthma are still limited.

METHODS

Literature without language limitation published before October 28, 2022, were retrieved from PubMed, EMBASE, and Cochrane Library. STATA 16.0 software was used for the meta-analysis of the extracted data. The results reported were symptom scores, drug scores, adverse effects rates, and cost of treatment.

RESULTS

Ten studies involving 1722 patients met the inclusion criteria. The total rhinitis score (TRSS) (weighted mean difference [WMD] = -1.23, 95% CI: -1.39--1.06, P < .001) and total asthma symptom score (TASS) (WMD = -1.00, 95% CI: -1.12-0.89, P < .001) were significantly lower in the SLIT group than the placebo group. The SLIT group had higher rates of treatment-related adverse events (relative risk [RR] = 2.82, 95% CI: 1.77-4.48, P < .001) and total costs of treatment (standardized mean difference [SMD] = 0.71, 95% CI: 0.45-0.97, P < .001). There was no significant difference in inhaled corticosteroids (ICS) dose (P = .195), fractional exhaled nitric oxide (FeNO) (P = .158), forced expiratory volume in 1 s (FEV1) (P = .237), and direct costs of treatment (P = .630) between the SLIT and placebo groups.

CONCLUSION

SLIT may be a therapeutic method for improving rhinitis symptoms and asthma symptoms in AR patients with asthma. However, as there was significant heterogeneity in results, more high-quality and well-designed studies are needed in the future to elucidate the efficacy of SLIT.

Pyrroloquinoline Quinone Administration Alleviates Allergic Airway Inflammation in Mice by Regulating the JAK-STAT Signaling Pathway

The current asthma therapies are inadequate for many patients with severe asthma. Pyrroloquinoline quinone (PQQ) is a naturally-occurring redox cofactor and nutrient that can exert a multitude of physiological effects, including anti-inflammatory and antioxidative effects. We sought to explore the effects of PQQ on allergic airway inflammation and reveal the underlying mechanisms. In vitro, the effects of PQQ on the secretion of epithelial-derived cytokines by house dust mite- (HDM-) incubated 16-HBE cells and on the differentiation potential of CD4+ T cells were investigated. In vivo, PQQ was administered to mice with ovalbumin- (OVA-) induced asthma, and lung pathology and inflammatory cell infiltration were assessed. The changes in T cell subsets and signal transducers and activators of transcription (STATs) were evaluated by flow cytometry. Pretreatment with PQQ significantly decreased HDM-stimulated thymic stromal lymphopoietin (TSLP) production in a dose-dependent manner in 16-HBE cells and inhibited Th2 cell differentiation in vitro. Treatment with PQQ significantly reduced bronchoalveolar lavage fluid (BALF) inflammatory cell counts in the OVA-induced mouse model. PQQ administration also changed the secretion of IFN-γ and IL-4 as well as the percentages of Th1, Th2, Th17, and Treg cells in the peripheral blood and lung tissues, along with inhibition the phosphorylation of STAT1, STAT3, and STAT6 while promoting that of STAT4 in allergic airway inflammation model mice. PQQ can alleviate allergic airway inflammation in mice by improving the immune microenvironment and regulating the JAK-STAT signaling pathway. Our findings suggest that PQQ has great potential as a novel therapeutic agent for inflammatory diseases, including asthma.

A review of allergen immunotherapy in asthma

Asthma is one of the most common chronic diseases worldwide. Besides symptomatic treatments, allergen immunotherapy (AIT) is a possible add-on treatment for asthmatic patients. In case of an immunologically proven allergen-driven mechanism of asthma, AIT represents the only etiologic treatment for allergic symptoms. AIT has proven both its efficacy and effectiveness in reducing asthma symptoms and asthma medications. It is still debated whether its prescription in severe asthmatic patients is allowed and safe. As for uncontrolled asthma, such a condition should be considered temporary, and AIT may be started as asthma becomes at least partially controlled after treatment adjustment. Finally, randomized trials and real-life studies in recent years have proven that AIT could be administered as a preventive strategy to reduce the risk of developing asthma in patients suffering from allergic rhinitis. More studies are needed to provide more precise indications on the role in clinical practice of AIT in asthmatic patients. Nevertheless, present data are already strong enough to highlight its role as a therapeutic option for allergic asthma and as a preventive strategy to stop or at least decelerate the allergic march.

2020 NAEPP Guidelines Update and GINA 2021-Asthma Care Differences, Overlap, and Challenges

The 2020 National Asthma Education and Prevention Program Coordinating Committee Expert Panel Working Group (NAEPP [2020 Focused Asthma Update]) guidelines and the Global Initiative for Asthma (GINA) 2021 strategy report are compared in this Rostrum article. The methodologies of each publication are described. Subsequently, 4 different selected pharmacological recommendations are compared in the 2 documents: step 1 for children 0 to 4 years of age with viral-induced wheezing, step 2 in ages 12 years and older with the intermittent use of inhaled corticosteroid, steps 3 and 4 with single-inhaler maintenance and reliever therapy with inhaled corticosteroids-formoterol (SMART), and steps 3, 4, and 5 with add-on long-acting muscarinic antagonist therapy. Nonpharmacological recommendations are also considered and contrasted, including for exhaled nitric oxide, environmental control, immunotherapy, and bronchial thermoplasty. Similarities and differences in these 2 documents are highlighted, and recommendations are made about harmonizing the approaches where possible.

Controversies in Allergy: A Pro/Con Review of Sublingual Allergen Immunotherapy and Allergic Asthma

Sublingual allergen immunotherapy (SLIT) is a therapeutic intervention used in the treatment of respiratory allergies, including asthma. Multiple randomized, double-blind, placebo controlled clinical trials have evaluated the efficacy and safety of SLIT for asthma. These data provide a good platform to appraise the evidence critically to evaluate the effect of SLIT in the management of asthma for the administration of SLIT by both SLIT drops and SLIT tablets, from a clinical perspective. In this clinical review, presented in a pro and con format, we examined (1) evidence from systematic reviews and meta-analyses; (2) clinical efficacy on asthma symptoms, asthma exacerbations, and quality of life; (3) clinical efficacy on reduction of asthma controller medication; (4) asthma severity; (5) safety profile; (6) long-term effect and prevention; (7) international guidelines, and (8) real-world evidence. Identified inconsistency in the data results from wide variations and differences in outcome measures, specific allergens, delivery approaches, schedules, and age groups. The house dust mite SLIT tablet demonstrated efficacy when it was used in the add-on management of house dust mite-associated allergic asthma in adults. Sublingual allergen immunotherapy for asthma may represent an important advance in incorporating a personalized medicine approach for patients with allergic asthma.

Advances in allergen immunotherapy as a treatment of asthma

Introduction: Specific immunotherapy is the only treatment acting on causes and not only on symptoms of respiratory allergy. It was first introduced as subcutaneous immunotherapy (SCIT) with the aim to induce immunological tolerance to the administered allergen(s). In the 1980s, sublingual immunotherapy (SLIT) was developed, mainly to improve the safety, which was a critical issue at that time.Areas covered: This article reviews the available literature, including a large number of randomized controlled trials, meta-analyses, and real-life studies as well, on the outcomes of SCIT and SLIT concerning the treatment critical issues of the two routes, that are efficacy, safety, cost-effectiveness, and compliance to treatment.Expert opinion: SCIT and SLIT are similarly effective in treating patients with respiratory allergy, providing, based on the induction of typical changes in the immunologic response, an early control of symptoms that steadily increases during the treatment and, once reached the recommended duration of 3 years, continues to work after stopping. This outcome is the major factor influencing the economic advantage of SCIT and SLIT over drug treatment.