Future Directions of Allergen Immunotherapy for Allergic Rhinitis: Experts' Perspective

Allergen immunotherapy (AIT) is broadly used all over the world as the only available disease-modifying treatment option. The aim of this experts' perspective is to address 7 important unmet needs for the further direction of AIT and to provide the readership with the authors' positions on these topics. An international group of experts in the field of AIT have formulated 7 important aspects for the future position of AIT, performed a current literature review, and proposed a consented position on these topics. The aspects discussed and consented by the authors include: (1) alternative routes of allergen application in AIT, (2) potential of recombinant vaccines, (3) the role of allergy diagnosis based on component-resolved diagnosis for AIT composition, (4) the impact of COVID-19 vaccination for further innovations in AIT, (5) potential of combining biologics to AIT, (6) future innovations in high-risk children/adolescents, and (7) the future regulatory position on AIT. Important unmet needs and topics for AIT have been addressed in this expert review. The authors' views and personal position on these 7 aspects have also been elaborated.

Aeroallergen immunotherapy associated with reduced risk of severe COVID-19 in 1095 allergic patients

Introduction

Allergen immunotherapy (AIT) brings along changes in the immune system, restoring dendritic cell function, reducing T2 inflammation and augmenting the regulatory cell activation. Coronavirus disease (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, interferes with the immune system causing immune suppression during the first phase and over-activation in more advanced disease. We decided to explore the interaction of both in a real-world observational trial.

Methods

We registered COVID-19 outcomes in patients with allergic disorders in Latin America, treated with and without AIT. The registry was conducted during the first 1.3 years of the pandemic, with most of the data collected before COVID-19 vaccination was concluded in most countries. Data collection was anonymous via a web-based instrument. Ten countries participated.

Results

630/1095 (57.6%) of the included patients received AIT. Compared to patients without AIT, those treated with AIT had a reduced risk ratio (RR) for COVID-19 lower respiratory symptoms (RR 0.78, 95% CI: 0.6703-0.9024; p = 0.001662) and need for oxygen therapy (RR 0.65, 95% CI: 0.4217-0.9992; p = 0.048). In adherent patients on maintenance sublingual immunotherapy/subcutaneous immunotherapy (SLIT/SCIT) the RR reduction was larger [RR = 0.6136 (95% CI 0.4623-0.8143; p < 0.001) and RR: 0.3495 (95% CI 0.1822-0.6701; p < 0.005), respectively]. SLIT was slightly more effective (NS). We excluded age, comorbidities, level of health care attendance, and type of allergic disorder as confounders, although asthma was related to a higher frequency of severe disease. When analyzing patients with allergic asthma (n = 503) the RR reduction favoring AIT was more pronounced with 30% for lower respiratory symptoms or worse (RR 0.6914, 95% CI 0.5264 to 0.9081, p = 0.0087) and 51% for need of oxygen therapy or worse (RR 0.4868, 95% CI 0.2829-0.8376, p = 0.0082). Among severe allergic patients treated with biologics (n = 24) only 2/24 needed oxygen therapy. There were no critical cases among them.

Conclusion

In our registry AIT was associated with reduced COVID-19 severity.

[Guidelines on atopic dermatitis for Mexico (GUIDAMEX): using the ADAPTE methodology]

With the advancement of knowledge in relation to the physiopathogenesis of atopic dermatitis (AD), several new therapeutic forms have been developed. There are also new guidelines for self-care. On the other hand, there is still an underdiagnosis of AD in Mexico. Thus, the need was seen to develop a national guide, with a broad base among the different medical groups that care for patients with AD. The Atopic Dermatitis Guidelines for Mexico (GUIDAMEX) was developed with the ADAPTE methodology, with the endorsement and participation of ten national medical societies, from physicians in Primary Healthcare to allergists and dermatologists. Throughout the manuscript, key clinical questions are answered that lead to recommendations and suggestions for the diagnosis of AD (including differential diagnosis with immunodeficiency syndromes), the recognition of comorbidities and complications, non-pharmacological treatment including therapeutic education, treatment of flares and maintenance therapy. The latter encompasses general measures to avoid triggering factors, first-line treatment focussed on repair of the skin barrier, second-line treatment (topical proactive therapy), and third-line phototherapy or systemic treatment, including dupilumab and JAK inhibitors.

An independent in-depth analysis proposing adjusted Global Initiative on Asthma (GINA) Step 1-2 treatment suggestions

The Global initiative on asthma (GINA) strategy included major changes for the treatment of mild asthma in the 2020 version, that are even taken to a next level in 2021, leaving a preferred track with only rescue therapy with inhaled corticosteroid and formoterol (ICS-FORM) for step 1-2 in 12+ years-old. It has been questioned how solid the evidence behind these recommendations is. We decided to independently conduct an in-depth analysis of published evidence based on a comprehensive evaluation of original articles and related appendices and publications, including quality of evidence and risk-of-bias per article. We first defined the major asthma treatment goals and proceeded to review how these were met in publications referenced in the main asthma guidelines. For patients with GINA 2021 Step 1 characteristics the analysis supports GINA's decision to avoid SABA monotherapy and to prefer ICS-FORM rescue with as alternative ICS rescue every time a SABA is used for ≥12 years, even though evidence is extrapolated from step 2 patients. For 6-11 year-olds we propose to consider ICS-FORM rescue as an alternative, as its use has been approved in this age-group, be it not as rescue-medication. For patients with GINA 2021 Step 2 characteristics our proposal slightly differs from GINA 2021. We propose to continue avoiding the separate use of SABA, using ICS rescue whenever a fast-acting bronchodilator is taken (even with ICS maintenance). Also, the superiority of ICS-FORM rescue over classical step 2 treatment is not uniform and year-long experience is lacking. Consequently for now, both treatment options seem equal: ICS-FORM rescue or ICS maintenance with SABA (+ICS) rescue. For 6-11 year-olds ICS rescue every time a SABA is used has the advantage of lower total ICS dose; as alternative we suggest ICS-FORM rescue. The best treatment option depends on patient characteristics and treatment goals. Recommendations should be reviewed as soon as new evidence becomes available.

[MIA 2021, Comprehensive Asthma Management. Guidelines for Mexico]

BACKGROUND

Asthma continues to be one of the most frequent chronic respiratory diseases in our country. New methods for diagnosis and treatment have been described; accordingly, the international guidelines were renewed.

OBJECTIVE

To create a national platform for the development of updated guidelines, solidly based on evidence: Comprehensive Asthma Management (Spanish acronym: MIA).

METHODS

MIA uses the ADAPTE method. The MIA development group consists of experts in pulmonology-allergology-methodology and representatives of 13 institutions and societies of specialties that manage asthma. The international reference guidelines (selected with AGREE-II): GINA 2020, GEMA 5.0, BTS/SIGN 2019 and ATS/ERS consensus document 2014-2019 on severe asthma. MIA covers suspected asthma, diagnosis, treatment, and special groups. Key clinical questions were formulated on treatment steps 1-3, biomarkers and severe asthma.

RESULTS

Based on evidence, safety, cost and local reality, the core group developed responses. Through a Delphi process the broad MIA development group suggested adjustments until consensus was reached.

CONCLUSION

A document was generated with multiple figures and algorithms, solidly based on evidence about asthma management, adjusted for Mexico with a broad base among different societies that participated in its development. It does not include guidelines for acute asthma.

Coronavirus disease 2019, allergic diseases, and allergen immunotherapy: Possible favorable mechanisms of interaction

Background: Both, allergen immunotherapy (AIT) and SARS-COV-2 infection cause a set of immunologic changes that respectively vary during the course of the treatment or the disease. Objective: To review immune changes brought along by each of these entities and how they might interrelate. Methods: We start presenting a brief review of the structure of the new coronavirus and how it alters the functioning of the human immune system. Subsequently, we describe the immune changes induced by AIT and how these changes could be favorable or unfavorable in the allergic patient infected with SARS-CoV-2 at a particular point of time during the evolving infection. Results: We describe how a healthy immune response against SARS-CoV-2 develops, versus an immune response that is initially suppressed by the virus, but ultimately overactivated, leading to an excessive production of cytokines (cytokine-storm-like). These changes are then linked to the clinical manifestations and outcomes of the patient. Reviewing the immune changes secondary to AIT, it becomes clear how AIT is capable of restoring a healthy innate immunity. Investigators have previously shown that the frequency of respiratory infections is reduced in allergic patients treated with AIT. On the other hand it also increases immunoregulation. Conclusion: As there are many variables involved, it is hard to predict how AIT could influence the allergic patient's reaction to a SARS-CoV-2 infection. In any case, AIT is likely to be beneficial for the patient with allergic rhinitis and/or allergic asthma in the context of the SARS-CoV-2 pandemic as controlling allergic diseases leads to a reduced need for contact with healthcare professionals. The authors remind the reader that everything in this article is still theoretical, since at the moment, there are no published clinical trials on the outcome of COVID-19 in allergic patients under AIT.

Enhancing innate immunity against virus in times of COVID-19: Trying to untangle facts from fictions

Introduction

In light of the current COVID-19 pandemic, during which the world is confronted with a new, highly contagious virus that suppresses innate immunity as one of its initial virulence mechanisms, thus escaping from first-line human defense mechanisms, enhancing innate immunity seems a good preventive strategy.

Methods

Without the intention to write an official systematic review, but more to give an overview of possible strategies, in this review article we discuss several interventions that might stimulate innate immunity and thus our defense against (viral) respiratory tract infections. Some of these interventions can also stimulate the adaptive T- and B-cell responses, but our main focus is on the innate part of immunity. We divide the reviewed interventions into: 1) lifestyle related (exercise, >7 h sleep, forest walking, meditation/mindfulness, vitamin supplementation); 2) Non-specific immune stimulants (letting fever advance, bacterial vaccines, probiotics, dialyzable leukocyte extract, pidotimod), and 3) specific vaccines with heterologous effect (BCG vaccine, mumps-measles-rubeola vaccine, etc).

Results

For each of these interventions we briefly comment on their definition, possible mechanisms and evidence of clinical efficacy or lack of it, especially focusing on respiratory tract infections, viral infections, and eventually a reduced mortality in severe respiratory infections in the intensive care unit. At the end, a summary table demonstrates the best trials supporting (or not) clinical evidence.

Conclusion

Several interventions have some degree of evidence for enhancing the innate immune response and thus conveying possible benefit, but specific trials in COVID-19 should be conducted to support solid recommendations.

[Mexican consensus on fractional exhaled nitric oxide (FeNO) in asthma 2020]

The fractional exhaled nitric oxide (FeNO) is related to the level of eosinophilic inflammation in the airways and the levels of interleukin-13, as such it could be a diagnostic and monitoring tool in asthma. A working group was convened between pulmonologists, respiratory physiology experts, and allergists to establish criteria for the use of FeNO in asthma in Mexico. Through a simplified Delphi method and group discussion, seven key points regarding the use of FeNO were agreed upon. We agree that the measurement of FeNO serves for the diagnosis of asthma in specialized clinics, both in children and adults, as well as to determine the level of corticosteroid treatment. In severe asthma, we recommend FeNO for endotyping, for detecting poor therapeutic adherence, undertreatment, and the risk of crisis. We suggest FeNO can be used to determine the level of corticosteroid treatment and to identify patients at risk of loss of lung function. We also recommend it in adults to improve the selection of biological therapy and, in this context, we only suggest it in selected cases for children.

[Executive Summary of ARIA 2019: Integrated care pathways for allergic rhinitis in Argentina, Spain and Mexico]

The health and economic impact of allergic diseases are increasing rapidly, and changes in management strategies are required. Its influence reduces the capacity of work and school performance by at least a third. The ICPs of the airways (integrated care pathways for respiratory diseases) are structured multidisciplinary healthcare plans, promoting the recommendations of the guidelines in local protocols and their application to clinical practice. This document presents an executive summary for Argentina, Mexico, and Spain. Next-generation ARIA guidelines are being developed for the pharmacological treatment of allergic rhinitis (AR), using the GRADE-based guidelines for AR, tested with real-life evidence provided by mobile technology with visual analogue scales. It is concluded that in the AR treatment, H1-antihistamines are less effective than intranasal corticosteroids (INCS), in severe AR the INCS represent the first line of treatment, and intranasal combination INCS + anti-H1 is more effective than monotherapy. However, according to the MASK real-life observational study, patients have poor adherence to treatment and often self-medicate, according to their needs.

Compromising between European and US allergen immunotherapy schools: Discussions from GUIMIT, the Mexican immunotherapy guidelines

Background

Allergen immunotherapy (AIT) has a longstanding history and still remains the only disease-changing treatment for allergic rhinitis and asthma. Over the years 2 different schools have developed their strategies: the United States (US) and the European. Allergen extracts available in these regions are adapted to local practice. In other parts of the world, extracts from both regions and local ones are commercialized, as in Mexico. Here, local experts developed a national AIT guideline (GUIMIT 2019) searching for compromises between both schools.

Methods

Using ADAPTE methodology for transculturizing guidelines and AGREE-II for evaluating guideline quality, GUIMIT selected 3 high-quality Main Reference Guidelines (MRGs): the European Academy of Allergy, Asthma and Immunology (EAACI) guideines, the S2k guideline of various German-speaking medical societies (2014), and the US Practice Parameters on Allergen Immunotherapy 2011. We formulated clinical questions and based responses on the fused evidence available in the MRGs, combined with local possibilities, patient's preference, and costs. We came across several issues on which the MRGs disagreed. These are presented here along with arguments of GUIMIT members to resolve them. GUIMIT (for a complete English version, Supplementary data) concluded the following.

Results

Related to the diagnosis of IgE-mediated respiratory allergy, apart from skin prick testing complementary tests (challenges, in vitro testing and molecular such as species-specific allergens) might be useful in selected cases to inform AIT composition. AIT is indicated in allergic rhinitis and suggested in allergic asthma (once controlled) and IgE-mediated atopic dermatitis. Concerning the correct subcutaneous AIT dose for compounding vials according to the US school: dosing tables and formula are given; up to 4 non-related allergens can be mixed, refraining from mixing high with low protease extracts. When using European extracts: the manufacturer's indications should be followed; in multi-allergic patients 2 simultaneous injections can be given (100% consensus); mixing is discouraged. In Mexico only allergoid tablets are available; based on doses used in all sublingual immunotherapy (SLIT) publications referenced in MRGs, GUIMIT suggests a probable effective dose related to subcutaneous immunotherapy (SCIT) might be: 50-200% of the monthly SCIT dose given daily, maximum mixing 4 allergens. Also, a table with practical suggestions on non-evidence-existing issues, developed with a simplified Delphi method, is added. Finally, dissemination and implementation of guidelines is briefly discussed, explaining how we used online tools for this in Mexico.

Conclusions

Countries where European and American AIT extracts are available should adjust AIT according to which school is followed.

[MASK (Mobile Airways Sentinel Network), a mobile App with ARIA's comprehensive solution in Spanish-speaking countries]

Although there are high quality clinical guidelines about allergic rhinitis, many patients receive deficient treatment, partly due to the high level of self-medication. MASK (Mobile Airways Sentinel Network) is an integral part of a project against chronic diseases which it is focused on active and healthy aging and is supported by the European Union. It forms the third phase of ARIA (Allergic Rhinitis and its Impact on Asthma) in which, through a mobile app on a smart device, the purpose is to guide patients in the control of their multimorbidity, allergic rhinitis or conjunctivitis, or asthma. The "Allergy Diary" app by MACVIA-ARIA is free and it is available for Android and iOS; on it, patients indicate how unpleasant the symptoms are on a daily basis through five screens with an analogous visual scale; two more screens were recently added (sleep affectation). With the app, it is also possible to download the information of the "Allergy Diary" on the physician's computer through a QR code at the moment of the medical consultation. In this article, we review the first year of experience in Spain, Mexico and Argentina, where the Spanish version is used.

[GUIMIT 2019, Mexican Guideline on Immunotherapy. Guideline on the diagnosis of IgE-mediated allergic disease and immunotherapy following the ADAPTE approach]

BACKGROUND

In Mexico, allergen immunotherapy (AIT) and immunotherapy with hymenoptera venom (VIT) is traditionally practiced combining aspects of the European and American school. In addition, both types of extracts (European and American) are commercially available in Mexico. Moreover, for an adequate AIT/VIT a timely diagnosis is crucial. Therefore, there is a need for a widely accepted, up-to-date national immunotherapy guideline that covers diagnostic issues, indications, dosage, mechanisms, adverse effects and future expectations of AIT (GUIMIT 2019).

METHOD

With nationwide groups of allergists participating, including delegates from postgraduate training-programs in Allergy/Immunology-forming, the guideline document was developed according to the ADAPTE methodology: the immunotherapy guidelines from European Academy of Allergy and Clinical Immunology, German Society for Allergology and Clinical Immunology, The American Academy of Allergy, Asthma and Immunology and American College of Allergy, Asthma, and Immunology were selected as mother guidelines, as they received the highest AGREE-II score among international guidelines available; their evidence conforms the scientific basis for this document.

RESULTS

GUIMIT emanates strong or weak (suggestions) recommendations about practical issues directly related to in vivo or in vitro diagnosis of IgE mediated allergic diseases and the preparation and application of AIT/VIT and its adverse effects. GUIMIT finishes with a perspective on AIT modalities for the future. All the statements were discussed and voted on until > 80 % consensus was reached.

CONCLUSIONS

A wide and diverse group of AIT/VIT experts issued transculturized, evidence-based recommendations and reached consensus that might improve and standardize AIT practice in Mexico.

Debates in Allergy Medicine: Allergy skin testing cannot be replaced by molecular diagnosis in the near future

Percutaneous skin prick tests (SPT) have been considered the preferred method for confirming IgE-mediated sensitization. This reliable and minimally invasive technique correlates with in vivo challenges, has good reproducibility, is easily quantified, and allows analyzing multiple allergens simultaneously. Potent extracts and a proficient tester improve its accuracy.

Molecular-based allergy diagnostics (MA-Dx) quantifies allergenic components obtained either from purification of natural sources or recombinant technology to identify the patient’s reactivity to those specific allergenic protein components. For a correct allergy diagnosis, the patient selection is crucial. MA-Dx has been shown to have a high specificity, however, as MA-Dx testing can be ordered by any physician, the pre-selection of patients might not always be optimal, reducing test specificity. Also, MA-Dx is less sensitive than in vitro testing with the whole allergen or SPT. Secondly, no allergen-specific immunotherapy (AIT) trial has yet shown efficacy with patients selected on the basis of their MA-Dx results. Thirdly, why would we need molecular diagnosis, as no molecular treatment can yet be offered? Then there are the practical arguments of costs (SPT highly cost-efficient), test availability for MA-Dx still lacking in wide areas of the world and scarce in others. As such, it is hard physicians can build confidence in the test and their interpretation of the MA-Dx results. In conclusion: as of now these techniques should be reserved for situations of complex allergies and polysensitization; in the future MA-Dx might help to reduce the number of allergens for AIT, but trials are needed to prove this concept.

Transfer of innovation on allergic rhinitis and asthma multimorbidity in the elderly (MACVIA-ARIA) - EIP on AHA Twinning Reference Site (GARD research demonstration project)

The overarching goals of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) are to enable European citizens to lead healthy, active and independent lives whilst ageing. The EIP on AHA includes 74 Reference Sites. The aim of this study was to transfer innovation from an app developed by the MACVIA-France EIP on AHA reference site (Allergy Diary) to other reference sites. The phenotypic characteristics of rhinitis and asthma multimorbidity in adults and the elderly will be compared using validated information and communication technology (ICT) tools (i.e. the Allergy Diary and CARAT: Control of Allergic Rhinitis and Asthma Test) in 22 Reference Sites or regions across Europe. This will improve the understanding, assessment of burden, diagnosis and management of rhinitis in the elderly by comparison with an adult population. Specific objectives will be: (i) to assess the percentage of adults and elderly who are able to use the Allergy Diary, (ii) to study the phenotypic characteristics and treatment over a 1-year period of rhinitis and asthma multimorbidity at baseline (cross-sectional study) and (iii) to follow-up using visual analogue scale (VAS). This part of the study may provide some insight into the differences between the elderly and adults in terms of response to treatment and practice. Finally (iv) work productivity will be examined in adults.

Allergen sensitization linked to climate and age, not to intermittent-persistent rhinitis in a cross-sectional cohort study in the (sub)tropics

BACKGROUND

Allergen exposure leads to allergen sensitization in susceptible individuals and this might influence allergic rhinitis (AR) phenotype expression. We investigated whether sensitization patterns vary in a country with subtropical and tropical regions and if sensitization patterns relate to AR phenotypes or age.

METHODS

In a national, cross-sectional study AR patients (2-70 y) seen by allergists underwent blinded skin prick testing with a panel of 18 allergens and completed a validated questionnaire on AR phenotypes.

RESULTS

628 patients were recruited. The major sensitizing allergen was house dust mite (HDM) (56%), followed by Bermuda grass (26%), ash (24%), oak (23%) and mesquite (21%) pollen, cat (22%) and cockroach (21%). Patients living in the tropical region were almost exclusively sensitized to HDM (87%). In the central agricultural zones sensitization is primarily to grass and tree pollen. Nationwide, most study subjects had perennial (82.2%), intermittent (56.5%) and moderate-severe (84.7%) AR. Sensitization was not related to the intermittent-persistent AR classification or to AR severity; seasonal AR was associated with tree (p < 0.05) and grass pollen sensitization (p < 0.01). HDM sensitization was more frequent in children (0-11 y) and adolescents (12-17 y) (subtropical region: p < 0.0005; tropical region p < 0.05), but pollen sensitization becomes more important in the adult patients visiting allergists (Adults vs children + adolescents for tree pollen: p < 0.0001, weeds: p < 0.0005).

CONCLUSIONS

In a country with (sub)tropical climate zones SPT sensitization patterns varied according to climatological zones; they were different from those found in Europe, HDM sensitization far outweighing pollen allergies and Bermuda grass and Ash pollen being the main grass and tree allergens, respectively. Pollen sensitization was related to SAR, but no relation between sensitization and intermittent-persistent AR or AR severity could be detected. Sensitization patterns vary with age (child HDM, adult pollen). Clinical implications of our findings are dual: only a few allergens -some region specific- cover the majority of sensitizations in (sub)tropical climate zones. This is of major importance for allergen manufacturers and immunotherapy planning. Secondly, patient selection in clinical trials should be based on the intermittent-persistent and severity classifications, rather than on the seasonal-perennial AR subtypes, especially when conducted in (sub)tropical countries.

Factors associated with allergic rhinitis in children from northern Mexico City

BACKGROUND

The International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire allows users to find factors associated with allergic diseases, but thus far most of the studies on risk factors for allergic diseases have been devoted to asthma and not to rhinitis.

OBJECTIVE

To determine the main factors associated with symptoms of allergic rhinitis and rhinoconjunctivitis in school children and adolescents in northern Mexico City.

PATIENTS AND METHODS

A cross sectional, multicenter survey was conducted in northern Mexico City, in children aged 6-7 and 13-14 years. The survey instrument was the Phase Three B ISAAC questionnaire, which was validated and standardized in Spanish.

RESULTS

There were 4106 6-7-year-olds and 6576 13-14-year-olds. The total prevalence of diagnosis of allergic rhinitis was 4.6%. The prevalence of cumulative and current symptoms of rhinitis was considered high (>29%), but the prevalence of the diagnosis of allergic rhinitis was considered low (ranging from 3.4% to 5.6%). The prevalence of symptoms of rhinitis with conjunctivitis had intermediate values (ranging from 20.3% to 30.2%). Cumulative symptoms of allergic rhinitis, current symptoms of allergic rhinitis, and rhinoconjunctivitis were related to symptoms of current or cumulative asthma, symptoms of current or cumulative atopic eczema, and current use of paracetamol (odds ratio > 1, P < .05).

CONCLUSION

The present results support the concept of rhinitis and asthma as common chronic respiratory diseases, and this study also found a relation between paracetamol use and rhinitis in children.