The Allergic Rhinitis Clinical Investigator Collaborative (AR-CIC): verification of nasal allergen challenge procedures in a study utilizing an investigational immunotherapy for cat allergy

Knowledge, Attitudes, and Practices of Patients with Allergic Rhinitis Towards Allergen-Specific Immunotherapy

Purpose

This study aimed to investigate the knowledge, attitudes, and practices (KAP) of patients with allergic rhinitis towards allergen-specific immunotherapy (AIT).

Methods

This cross-sectional study was conducted through a questionnaire survey at The Fourth Affiliated Hospital of Zhejiang University School of Medicine from October 15, 2023, to December 3, 2023.

Results

A total of 550 valid questionnaires were included in the analysis. The median scores with interquartile ranges (IQR) for knowledge, attitude, and practice were 17 (11, 23), (possible range: 0-34); 20 (17, 22), (possible range: 7-35); and 30 (24, 34), (possible range: 8-40). Multivariate logistic regression analysis showed that individuals engaging in physical activity 1-3 times per week (OR = 2.895, 95% CI: [1.745, 4.804], P < 0.001), those participating in physical activity 5-7 times per week (OR = 3.811, 95% CI: [1.502, 9.671], P = 0.005), and those with higher knowledge scores (OR = 4.485, 95% CI: [2.942, 6.837], P < 0.001) were independently associated with positive practices. The structural equation modeling (SEM) results revealed that knowledge had a significant influence on attitude (β = -0.354, P = 0.010) and practice (β = 0.618, P = 0.010), and attitude also demonstrated a noteworthy impact on practice (β = -0.120, P = 0.020). Furthermore, it is worth noting that the indirect effects of knowledge on practice were statistically significant (β = 0.042, P = 0.020).

Conclusion

Patients with allergic rhinitis had inadequate knowledge, negative attitudes and proactive practices towards AIT. To improve their understanding and adherence, healthcare providers should prioritize education and interventions aimed at enhancing patient engagement with this treatment option.

Study of Cat Allergy Using Controlled Methodology-A Review of the Literature and a Call to Action

The prevalence of cat allergen-induced AR is increasing worldwide, prompting its study using controlled methodology. Three general categories of allergen exposure models currently exist for the study of cat allergen-induced AR: natural exposure cat rooms, allergen exposure chambers (AEC), and nasal allergen challenges (NAC). We evaluated existing literature surrounding the use of these models to study cat allergen induced AR using online research databases, including OVID Medline, Embase, and Web of Science. We report that natural exposure cat rooms have been important in establishing the foundation for our understanding of cat allergen-induced AR. Major limitations, including variable allergen ranges and differing study designs highlight the need for a more standardized protocol. In comparison, AECs are an exceptional model to mimic real-world allergen exposure and study long-term implications of AR with large sample sizes. Existing AECs are limited by heterogeneous facility designs, differing methods of cat allergen distribution, and issues surrounding cost and accessibility. Conversely, NACs allow for smaller participant cohorts for easier biological sampling and are ideal for phase I, phase 2 or proof-of-concept studies. NACs generally have a standardized protocol and are less expensive compared to AECs. Nevertheless, NACs solely capture acute allergen exposure and have the further limitation of using allergen extracts rather than natural allergen. As the use of combined controlled methodologies is sparse, we recommend concurrent use of AECs and NACs to study short- and long-term effects of AR, thereby providing a more holistic representation of cat allergen-induced AR.

Immunoregulatory T cell epitope peptides for the treatment of allergic disease

Allergic diseases are type 2 inflammatory reactions with an increasing worldwide prevalence, making the search for new therapeutic options pertinent. Allergen immunotherapy is the only disease-modifying approach for allergic rhinitis, though it can result in systemic reactions. Recently, peptide immunotherapy (PIT), involving T-cell epitope peptides that bind to major histocompatibility complexes, have been developed. It is speculated that they can induce T helper cell type 2 anergy, Treg cell upregulation or immune deviation. Promising results in cat dander, honeybee venom, Japanese cedar pollen, grass pollens, ragweed and house dust mite clinical trials have shown safety, efficacy and tolerability to PIT. Hence, PIT may hold the potential to change the treatment algorithm for allergic rhinitis.

Effect of Medical Therapy in Allergic Rhinitis: A Systematic Review and Meta-Analysis

BACKGROUND

Intranasal corticosteroids (INCS), oral antihistamines (POAH), and allergen-specific immunotherapy (ASIT) are widely used in the treatment of allergic rhinitis (AR); however, appraisal of treatment effect has been heterogenous, and few studies have interpreted these outcomes in context with measures of nasal airflow.

OBJECTIVE

To provide a systematic review and meta-analysis of randomized placebo-controlled trials for common therapy classes for AR to assess standardized treatment effect on validated patient-reported outcomes and physiologic measures of airflow.

METHODS

A systematic search was performed in PubMed, Scopus, OVID, and Cochrane library databases to identify randomized controlled trials meeting inclusion criteria. Treatment effects of INCS, POAH, and ASIT on total nasal symptom score (TNSS), visual analog scale (VAS), Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), and peak nasal inspiratory flow (PNIF) were analyzed by meta-analysis.

RESULTS

Twenty-two studies with 4673 AR patients were identified, with 5 INCS, 8 POAH, and 9 ASIT trials. INCS improved TNSS (mean difference [MD] 0.90; P = .002) and PNIF (MD 13.31 L/min [P = .0007]. POAH improved quality of life assessed by RQLQ [MD 0.36; P < .001], but no improvement was found in PNIF. ASIT improved RQLQ [MD 0.65; P < .001], with a trend toward improvement in TNSS.

CONCLUSION

Overall, INCS resulted in a clinically and statistically meaningful improvement in symptom scores and physiologic measures in AR. POAH and ASIT both improved symptom scores and quality of life, but their impacts upon nasal airflow are uncertain. There is a lack of studies assessing the effect of INCS on quality of life and the effect of POAH on symptom severity, particularly for mild AR. Future studies should assess the effect of treatment for each of these patient-reported measures.

Systematic review of measures of disease severity in rhinitis

BACKGROUND

Rhinologists often encounter a broad spectrum of allergic rhinitis (AR) and nonallergic rhinitis (NAR) patients, who can be variably classified based upon timing and severity of disease. Our understanding of the varied quality of life (QOL) impact in different classifications of rhinitis is limited. Thus a more comprehensive understanding of the impact of rhinitis upon our patients, as measured by both patient reported outcome measures (PROMs) and clinical physiologic measures, as well as unique factors associated with disease severity is needed.

METHODS

A systematic search of databases was performed to identify AR and NAR studies reporting Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), total nasal symptom score (TNSS), or visual analogue scale (VAS) scores, and physiologic measures including peak nasal inspiratory flow (PNIF) and nasal airflow. Relationships between PROMs, physiologic measures, and associated factors (e.g., allergic status, disease duration) were assessed by weighted correlations and meta-regressions.

RESULTS

A total of 171 studies reporting on 33,843 patients were included. Symptoms were more severe in AR than NAR on VAS (p < 0.001). Classification based upon Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines demonstrated differences in PROM severity. There was no significant correlation between PROMs and demographic factors, comorbidities, or physiologic measures. Meta-regression identified a correlation between worse RQLQ scores and shorter disease duration (r = -0.4, p < 0.001).

CONCLUSION

Rhinitic patients have more severe impact upon QOL in the presence of allergy with variable impact upon specific symptom subdomains. PROMs do not correlate with common demographic factors, comorbidities, or physiologic measures of nasal airflow.

Development of nasal allergen challenge with cockroach in children with asthma

BACKGROUND

Nasal allergen challenge (NAC) could be a means to assess indication and/or an outcome of allergen-specific therapies, particularly for perennial allergens. NACs are not commonly conducted in children with asthma, and cockroach NACs are not well established. This study's objective was to identify a range of German cockroach extract doses that induce nasal symptoms and to assess the safety of cockroach NAC in children with asthma.

METHODS

Ten adults (18-37 years) followed by 25 children (8-14 years) with well-controlled, persistent asthma and cockroach sensitization underwent NAC with diluent followed by up to 8 escalating doses of cockroach extract (0.00381-11.9 µg/mL Bla g 1). NAC outcome was determined by Total Nasal Symptom Score (TNSS) and/or sneeze score. Cockroach allergen-induced T-cell activation and IL-5 production were measured in peripheral blood mononuclear cells.

RESULTS

67% (6/9) of adults and 68% (17/25) of children had a positive NAC at a median response dose of 0.120 µg/mL [IQR 0.0380-0.379 µg/mL] of Bla g 1. Additionally, three children responded to diluent alone and did not receive any cockroach extract. Overall, 32% (11/34) were positive with sneezes alone, 15% (5/34) with TNSS alone, and 21% (7/34) with both criteria. At baseline, NAC responders had higher cockroach-specific IgE (P = .03), lower cockroach-specific IgG/IgE ratios (children, P = .002), and increased cockroach-specific IL-5-producing T lymphocytes (P = .045). The NAC was well tolerated.

CONCLUSION

We report the methodology of NAC development for children with persistent asthma and cockroach sensitization. This NAC could be considered a tool to confirm clinically relevant sensitization and to assess responses in therapeutic studies.

The use of nasal allergen vs allergen exposure chambers to evaluate allergen immunotherapy

INTRODUCTION

Allergen-specific immunotherapy (AIT) is the only disease-modifying treatment option for allergic rhinitis (AR) patients with persistent moderate-severe AR for whom traditional pharmacotherapies are ineffective. The nasal allergen challenge (NAC) and allergen exposure chamber (AEC) are two translational models of AR that can be used to investigate the properties, safety, and efficacy of AIT.

AREAS COVERED

Peer-reviewed, human-centered articles utilizing AEC or NAC models to investigate AIT between 2010 and 2020 were curated from PubMed, EMBASE, and OVID Medline databases. AECs have been used to evaluate traditional subcutaneous and sublingual administrations of AIT, including cross-protective effects and different dosing regimens. More recently, the effectiveness of novel AIT formulations has been evaluated. NACs are another model used to study AIT, including using novel intralymphatic routes of administration. It is an especially powerful and versatile tool to determine if basic science and animal model findings are clinically translatable.

EXPERT OPINION

The AEC and NAC models both produce clinically relevant and reproducible results. AECs are more effective for studying many participants but are limited because they require a specialized facility. As more AIT therapies and new formulations are developed over time, the versatility of the NAC will be especially useful.

Clinical symptoms and biomarkers of Bermuda grass-induced allergic rhinitis using the nasal allergen challenge model

BACKGROUND

Bermuda grass is a prevalent allergen that flourishes in tropical climates. Its exposure is traditionally believed to be low in Ontario due to the colder environment. However, high sensitization rates have been observed in Kingston, Ontario.

OBJECTIVE

We sought to investigate whether its allergens can provoke allergic rhinitis (AR) symptoms in sensitized participants from south-eastern Ontario and determine if nasal allergen challenge (NAC) model is appropriate to study Bermuda grass-induced AR.

METHODS

Twenty-one participants sensitized to Bermuda grass and 12 nonallergic participants completed a titrated NAC with increasing allergen concentrations at a screening visit. Total nasal symptom score (TNSS) and peak nasal inspiratory flow were collected before allergen exposure and 10 minutes after delivery of each concentration. Twelve participants with a Bermuda grass allergy who met the qualifying criteria (TNSS ≥ 8 and peak nasal inspiratory flow fall ≥ 50%) and 11 nonallergic controls returned for single-dose NAC visit.

RESULTS

At titrated NAC, 19 of 21 sensitized participants met the criteria of positive allergic response when challenged. During single-dose NAC, participants with allergy had significantly greater TNSS between 15 minutes and 3 hours after NAC than controls. Likewise, allergic participants had a significantly increased number of nasal lavage eosinophils at both 1 and 6 hours after NAC. Bermuda grass-specific immunoglobulin E was significantly increased in Bermuda grass allergic participants at NAC than screening visit.

CONCLUSION

Although Bermuda grass is a non-native allergen in Ontario, it can induce AR symptoms in sensitized participants, and the NAC model is appropriate to study Bermuda grass-induced AR.

Highlights and recent developments in airway diseases in EAACI journals (2018)

The European Academy of Allergy and Clinical Immunology (EAACI) supports three journals: Allergy, Pediatric Allergy and Immunology, and Clinical and Translational Allergy. EAACI's major goals include supporting the promotion of health, in which the prevention of allergy and asthma plays a critical role, and disseminating the knowledge of allergic disease to all stakeholders. In 2018, the remarkable progress in the identification of basic mechanisms of allergic and respiratory diseases as well as the translation of these findings into clinical practice were observed. Last year's highlights include publication of EAACI guidelines for allergen immunotherapy, many EAACI Position Papers covering important aspects for the specialty, better understanding of molecular and cellular mechanisms, identification of biomarkers for disease prediction and progress monitoring, novel prevention and intervention studies, elucidation of mechanisms of multimorbidities, introduction of new drugs to the clinics, recently completed phase three clinical studies, and publication of a large number of allergen immunotherapy studies and meta-analyses.

Analysis of expression of ILC2 cells in nasal mucosa based on animal model of allergic bacterial infection rhinitis

The objective of this study is to analyze the expression of ILC2 cells (type 2 innate lymphoid cells) in nasal mucosa based on animal model of allergic bacterial infection rhinitis. 45 female BALB/c mice were selected as research subject. They were randomly divided into control group (group A), sensitization group (group B) and inhibitor group (group C) to establish a mouse model of allergic rhinitis. The pathological changes of mouse nasal mucosa were observed by HE (hematoxylin-eosin) staining. The number of ILC2 cells in mouse nasal mucosa was detected by immunofluorescence double staining assay. Real-time quantitative Polymerase Chain Reaction (PCR) was used to detect the expression of ILC2 cell-associated factor in mouse nasal mucosa. The expression of cytokine protein in serum was detected by enzyme linked immunosorbent assay. The results showed that there was no inflammatory cell infiltration in the nasal mucosa of group A, and the number of ILC2 cells was small. Inflammatory cell infiltration and obvious ILC2 cells were observed in the nasal mucosa of group B and C, and the number of ILC2 cells in group B and C was significantly increased compared with that in group A. Compared with group A, ROR α, Thy-1, ST2, and CD90 genes were significantly increased in nasal mucosa tissues of group B and C, and protein levels of IL-4, IL-5, IL-13, and IgE in serum were significantly increased. Compared with group B, the protein expression levels of IL-13 and IgE in serum of group C mice were significantly increased, while the expression levels of IL-4 and IL-5 were not significantly different. In conclusion, in the pathogenesis of allergic rhinitis, ILC2 cells play a role in promoting the development of inflammation, and its expression is related to RORα, Thy-1, ST2 and CD90. Meanwhile, ILC2 cells are also important cells for the synthesis and secretion of IL-13. The study on the pathogenesis of allergic rhinitis provides a new target for its treatment.

Keep the cat, change the care pathway: A transformational approach to managing Fel d 1, the major cat allergen

Background

Allergies to cats are the most common animal‐origin allergy, and affect approximately 1 in 5 adults worldwide. The prevalence of allergy to furry animals has been increasing, and allergy to cats is a major risk factor for the development of asthma and rhinitis. The diagnosis of cat allergy is now well established. The exact significance of component‐resolved diagnosis in the diagnosis of cat allergy remains to be fully understood. Allergen avoidance is effective but often has a psychologic impact. Allergen immunotherapy is not well demonstrated. There is a need for innovative approaches to better manage cat allergens. Next‐generation care pathways for asthma and rhinitis will define the place of cat allergen avoidance.

Methods and Results

This manuscript, based on content presented at the European Academy of Allergy and Clinical Immunology Congress 2019, provides information on the prevalence and impact of cat allergies and the molecular biology of Fel d 1, the major cat allergen.

Discussion

The authors present the scientific basis of a novel care pathway that utilizes anti‐Fel d 1 IgY antibodies to safely and effectively neutralize Fel d 1 after its production by the cat but before human exposure.

Conclusion

Efficacy of a feline diet with an egg product ingredient containing anti‐Fel d 1 IgY antibodies was demonstrated in vitro, ex vivo, and in vivo, and further validated by a pilot exposure study involving cat‐allergic human participants.

Nasal challenges in allergen immunotherapy trials

PURPOSE OF REVIEW

The nasal allergen challenge (NAC) model can be a valuable diagnostic tool for allergic rhinitis. Alongside its clinical use, NACs can be used as primary and secondary endpoints in studies evaluating allergen immunotherapy (AIT) products for allergic rhinitis treatment. This review will discuss the technical aspects of the NAC model and provide a summary of recent studies using NACs to assess existing and new AIT treatments.

RECENT FINDINGS

Over the last 2 years, both titrated and single-dose nasal challenge protocols have been used to evaluate immunotherapies targeting grass, birch, house dust mite, and cat allergens. Early efficacy and dose-finding trials showed improvements in allergic symptoms and nasal tolerance to allergens after AIT treatment with standardized extracts or modified forms of whole allergen. NACs were also used in two proof-of-concept studies to illustrate the efficacy of intralymphatic immunotherapy with two concomitant allergens and subcutaneous immunotherapy with Fel d 1-specific IgG-blocking antibodies.

SUMMARY

Along with existing therapies, nasal challenges are useful in evaluating AIT treatments in the very early stages of clinical development. However, because of the variety in challenge techniques and symptom assessments available, special attention must be placed in the protocol design in order to compare the study results with existing NAC publications.