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

Focused allergic rhinitis practice parameter for Canada

Allergic rhinitis (AR) is a prevalent disease in Canada that affects both children and adults. Several guidelines for the management of AR have been published by professional allergy societies worldwide. However, there are regional differences in the clinical management of AR, and regulatory approval of some AR pharmacotherapies varies among countries. Thus, six research questions specific to the treatment of AR in Canada were identified for this focused practice parameter. Reviews of the literature published since 2016 were conducted to obtain evidence-based support for the responses of the Work Group to each research question. In response to research question 1 "In patients with symptoms indicative of AR, is serum-specific IgE sufficient to identify candidates for immunotherapy or is a skin prick test mandatory?" the Work Group concluded that either sIgE testing or skin prick test are acceptable for diagnosing AR and guiding immunotherapy. In response to research question 2 "When taking into account the preferences of the patient and the prescriber (stakeholder engagement) should second-generation oral antihistamine (OAH) or intranasal corticosteroid (INCS) be first line?" the Work Group concluded that existing guidelines generally agree on the use of INCS as a first-line therapy used for AR, however, patient and provider preferences and considerations can easily shift the first choice to a second-generation OAH. In response to research question 3 "Is a combination intranasal antihistamine (INAH)/INCS formulation superior to INCS plus OAH? Do they become equivalent after prolonged use?" the Work Group concluded that that the combination INAH/INCS is superior to an INCS plus OAH. However, there was insufficient evidence to answer the second question. In response to research question 4 "Do leukotriene receptor antagonists (LTRA) have a greater benefit than OAH in AR for some symptoms to justify a therapeutic trial in those who cannot tolerate INCS?" the Work Group concluded that LTRAs have inferior, or at best equivalent, daytime or overall symptom control compared with OAH, but LTRAs may improve nighttime symptom control and provide benefits in patients with AR and concomitant asthma. In response to research question 5 "Should sublingual immunotherapy (SLIT) tablets be considered first-line immunotherapeutic options over subcutaneous immunotherapy (SCIT) based on the evidence of efficacy?" the Work Group concluded that the choice of SLIT or SCIT cannot be made on efficacy alone, and differences in other factors outweigh any differences in efficacy. In response to research question 6 "Based on efficacy data, should ALL patients seen by an allergist be offered SLIT or SCIT as a treatment option?" the Work Group concluded that the efficacy data suggests that SLIT or SCIT should be used broadly in patients with AR, but other clinical concerns also need to be taken into consideration.

A Meta-Analysis Investigating the Efficacy and Safety of Allergen-Specific Immunotherapy in the Management of Respiratory Allergies

Background: This meta-analysis aimed to evaluate the effectiveness and adverse effects of specific immunotherapy (SIT) in the management of respiratory allergens, including allergic asthma, rhinitis, and related disorders, based on a review of current literature up to November 8, 2022.Methods: We conducted a search of databases, including PubMed, Embase, Cochrane, and Web of Science, to identify relevant randomized controlled trials (RCTs) assessing respiratory allergy-specific immunotherapy. We employed the Consolidated Standards of Reporting Trials (CONSORT) Statement to select RCTs that adhered to rigorous reporting standards. Specifically, we focused on double-blind placebo-controlled (DBPC) trials and open studies involving both adults and children, considering factors such as dosage, inclusion criteria, allergens, and primary outcome measurements.Results: A total of 25 meta-analyses were included in this study. Among them, 14 evaluated sublingual specific allergen immunotherapy (SLIT), 4 assessed subcutaneous allergen immunotherapy (SCIT), 4 explored both sublingual and subcutaneous immunotherapy, and 3 investigated intralymphatic immunotherapy. The outcomes of these meta-analyses indicated a reduction in medication scores in 20 cases and a decrease in symptom scores in 23 cases. Additionally, six studies reported on changes in IgE levels, seven studies focused on IgG4, four studies examined FEV1 (forced expiratory volume in one second), and eight studies reported on symptom and medication scores. Furthermore, eleven studies reported on differences in adverse reactions.Conclusion: The results of our meta-analysis suggest that specific immunotherapy, while associated with some adverse effects, effectively reduces the symptoms of asthma and rhinitis. Therefore, we recommend its use in the treatment of respiratory allergies.

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.

Malaysian Society of Allergy and Immunology Consensus Statement on Sublingual Immunotherapy in Allergic Rhinitis

Allergic rhinitis (AR) is an IgE-mediated inflammatory disease of the upper airway. AR affects the patients' quality of life, is a known risk factor for asthma and a socio-economic burden. Allergen-specific immunotherapy (AIT), comprising sublingual immunotherapy (SLIT) and subcutaneous immunotherapy (SCIT), involves administering increasing doses of the causative allergen to induce clinical and immunologic tolerance to the allergens. It is the only currently available treatment for AR that has been proven to induce disease-modifying effects (i.e., long-term remission of allergic symptoms or potential prevention of asthma and new sensitizations). Although AIT is conventionally recommended for patients who are non-responsive to symptom-relieving pharmacotherapy, it is presently recommended as a first-line treatment for patients with moderate to severe AR who prefer a treatment with the potential for long-term remission. In light of the relatively recent implementation of AIT in Malaysia, guidelines on its appropriate indication and application are important to attain optimal outcomes. This consensus statement was developed by an expert group formed by the Malaysian Society of Allergy and Immunology to provide evidence-based recommendations for the practice of AIT in Malaysia. Patient and product selection, choice of AIT, and strategy towards an effective treatment outcome in AIT are presented.

House Dust Mite and Grass Pollen Allergen Extracts for Seasonal Allergic Rhinitis Treatment: A Systematic Review

BACKGROUND

The treatment of allergic rhinitis is important due to the burden that the disease causes globally. The objective of this review is to explore the efficiency of house dust mite and grass pollen extracts in allergic rhinitis treatment.

METHODS

We performed research in electronic databases and searched relevant articles on PubMed, CINAHL, OVID, ScienceDirect, Cochrane CENTRAL, and MEDLINE. We used keywords such as 'allergic rhinitis', 'sublingual immunotherapy', 'randomized controlled trials', 'grass pollen', 'allergen immunotherapy', and 'house dust mite'. We included nine randomized controlled trials (RCTs). Quality assessment of included studies was performed independently by two authors.

RESULTS

We included nine eligible RCTs in this review. Five RCTs were about grass pollen extracts and four RCTs were about house dust mite extracts. Most of the studies reported positive results and suggested further evaluation of sublingual immunotherapy (SLIT) treatment. Grass pollen extracts mostly used were Dactylis glomerata, Poa pratensis, Lolium perenne, Anthoxanthum odoratum, Phleum pratense, and Parietaria. House dust mite extracts used were from Dermatophagoides pteronyssinus and Dermatophagoides farina. According to the quality assessment, no bias was observed in the included studies.

CONCLUSIONS

Although sublingual allergen immunotherapy shows a benefit compared to placebo in the treatment of allergic rhinitis and rhino-conjunctivitis in adults, the results are interpreted with caution due to the high heterogenicity among studies in treatment protocols and dosing. More standardization among studies is needed.

Local nasal immunotherapy for allergic rhinitis: A systematic review and meta-analysis

INTRODUCTION

Local nasal immunotherapy (LNIT), an alternative noninjection immunotherapy method, is theoretically an efficient method for inducing immunotolerance directly in the affected organ. LNIT is more convenient and less invasive than injection immunotherapy, with fewer systemic reactions. The development of adjuvants to overcome LNIT's limitations raises the possibility of it being an alternative allergen immunotherapy.

OBJECTIVES

To evaluate the clinical and immunological efficacy and safety of LNIT for patients with allergic rhinitis.

METHODS

A systematic search for randomized controlled trials comparing LNIT and placebo was performed using OVID Medline and Embase. Outcomes were total nasal symptom score (TNSS), symptom-medication score (SMS), medication score, immunological assessment, and nasal provocation threshold. Data were pooled for meta-analysis.

RESULTS

A total of 20 studies with 698 participants were included. The LNIT group had greater posttreatment improvement in TNSS, SMS, and medication score than control (TNSS: standardized mean difference [SMD], -1.37 [95% confidence interval [CI], -2.04 to -0.69]; SMS: SMD, -1.55 [95% CI, -2.83 to -0.28]; and medication score: SMD, -1.09 [95% CI, -1.35 to -0.83]). Immunological assessments showed no significant differences in serum-specific IgE (mean difference [MD], 6.35; 95% CI, -4.62 to 17.31), nasal IgE (MD, -0.59; 95% CI, -1.99 to 0.81), or nasal eosinophil cationic protein (MD, 7.63; 95% CI, -18.65 to 33.91). Only serum IgG significantly increased with LNIT (MD, 0.45; 95% CI, 0.20, 0.70). Posttreatment, nasal provocation threshold was higher with LNIT (MD, 27.30; 95% CI, 10.13-44.46). No significant adverse events were reported.

CONCLUSIONS

LNIT is a safe alternative allergen immunotherapy route without significant adverse events. It improves clinical symptoms, reduces medication usage, and increases the nasal provocation threshold.

Circulating MIF Associated With Disease Severity and Clinical Response of Sublingual Immunotherapy in House Dust Mite-Induced Allergic Rhinitis

Background: Macrophage migration inhibitory factor (MIF) is described as a pro-inflammatory cytokine involved in many inflammatory and allergic disorders, but the role of MIF in allergic rhinitis (AR) remains poorly clarified. The aim of this study was to investigate the association between circulating MIF levels and house dust mite (HDM)-induced AR, and evaluate MIF as a potential biomarker in reflecting disease severity and predicting the clinical response of sublingual immunotherapy (SLIT) in HDM-induced AR patients.

Methods: In this study, we enrolled 160 persistent HDM-induced AR patients (AR group), including 48 mild AR patients (MAR group) and 112 moderate–severe AR patients (MSAR group), and 77 healthy controls (HC group). Circulating levels of MIF were measured by ELISA, and the relationship between MIF concentrations and disease severity was assessed. In the MSAR group, 106 patients were assigned to receive SLIT for 3 years. At the end of the study, patients were categorized into good response group and poor response group, and associations between clinical variables or biomarkers and clinical response were analyzed by the multivariate regression analysis.

Results: The concentrations of serum MIF were significantly higher in AR patients than in HCs, especially in those with MSAR. Moreover, circulating MIF levels were positively correlated with TNSS, VAS, serum HDM–specific IgE, total IgE, blood eosinophil count, and blood eosinophil percentage (all p < 0.05). Eighty MSAR patients finally completed SLIT, 45 patients obtained good response, and 35 patients resulted in poor response. The serum levels of MIF were significantly lower in the good-response group than in the poor-response group (p < 0.001). The receiver operating characteristic analysis for MIF showed good accuracy for predicting clinical response of SLIT (area under the curve = 0.877, p < 0.001). The multivariate regression analysis demonstrated that serum MIF was an independent factor for SLIT responsiveness.

Conclusion: Serum MIF appeared to be an important biological indicator in reflecting disease severity and an independent predictor for clinical responsiveness of SLIT in HDM-induced AR patients.

Allergen immunotherapy and biologics in respiratory allergy: friends or foes?

PURPOSE OF REVIEW

Allergen-specific immunotherapy has established as an indispensable disease-modifying treatment in allergy practice but its safety and efficacy might be furtherly improved by combining it with other drugs or therapeutic intervention that co-modulate immune type 2 immune networks.

RECENT FINDINGS

In the past two decades, clinical research focused on AIT and omalizumab co-treatment to improve both safety and long-term efficacy of allergic disease treatment. Recently, combination of AIT with other biologicals targeting different mediators of type 2 inflammation has been set up with interesting preliminary results. Moreover, AIT current contraindication might be overcome by contemporarily controlling underlying type 2 inflammation in severe atopic patients.

SUMMARY

AIT--biological combination treatment can realize a complex multitargeted treatment strategy allowing for consistently improving disease control and sparing steroid administration.

Activated leukocyte cell adhesion molecule as a biomarker for disease severity and efficacy of sublingual immunotherapy in allergic rhinitis

BACKGROUND

Activated leukocyte cell adhesion molecule (ALCAM) plays an important role in T cell activation and immune response, but the role of ALCAM in allergic rhinitis (AR) remains unclear. The objective of the current study was to validate serum ALCAM as a biomarker in assessing disease severity and predicting the efficacy of sublingual immunotherapy (SLIT) in AR patients.

METHODS

We recruited 40 healthy controls (HC group), 38 mild AR patients (MAR group) and 80 moderate-severe AR patients (MSAR group) in this study. Serum levels of ALCAM were determined by ELISA, and the association between ALCAM levels and disease severity was evaluated. In the MSAR group, 68 patients underwent and finished 3-years of SLIT, and were divided into effective group and ineffective group, the relationship between ALCAM levels and efficacy of SLIT was exampled.

RESULTS

ALCAM levels were elevated in the serum of AR patients in comparison with HC. Moreover, serum ALCAM concentrations were higher in MSAR group than in MAR group and HC group, and levels of ALCAM significantly correlated with AR total nasal symptom score (TNSS) (r = 0.330, P < 0.001), visual analogue scale (VAS) (r = 0.387, P < 0.001) and serum total IgE levels (r = 0.442, P < 0.001). In the effective group, the ALCAM levels were significantly lower than in the ineffective group. Receiver operating characteristic (ROC) curve exhibited good accuracy for predicting clinical efficacy of SLIT (area under the curve = 0.805, P < 0.001).

CONCLUSIONS

The serum ALCAM maybe a novel biomarker for assessing disease severity and predicting clinical efficacy of SLIT in AR patients.