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

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.

International consensus statement on allergy and rhinology: Allergic rhinitis - 2023

BACKGROUND

In the 5 years that have passed since the publication of the 2018 International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis (ICAR-Allergic Rhinitis 2018), the literature has expanded substantially. The ICAR-Allergic Rhinitis 2023 update presents 144 individual topics on allergic rhinitis (AR), expanded by over 40 topics from the 2018 document. Originally presented topics from 2018 have also been reviewed and updated. The executive summary highlights key evidence-based findings and recommendation from the full document.

METHODS

ICAR-Allergic Rhinitis 2023 employed established evidence-based review with recommendation (EBRR) methodology to individually evaluate each topic. Stepwise iterative peer review and consensus was performed for each topic. The final document was then collated and includes the results of this work.

RESULTS

ICAR-Allergic Rhinitis 2023 includes 10 major content areas and 144 individual topics related to AR. For a substantial proportion of topics included, an aggregate grade of evidence is presented, which is determined by collating the levels of evidence for each available study identified in the literature. For topics in which a diagnostic or therapeutic intervention is considered, a recommendation summary is presented, which considers the aggregate grade of evidence, benefit, harm, and cost.

CONCLUSION

The ICAR-Allergic Rhinitis 2023 update provides a comprehensive evaluation of AR and the currently available evidence. It is this evidence that contributes to our current knowledge base and recommendations for patient evaluation and treatment.

Neuronal-Immune Cell Units in Allergic Inflammation in the Nose

Immune cells and immune-derived molecules, endocrine glands and hormones, the nervous system and neuro molecules form the combined tridirectional neuroimmune network, which plays a significant role in the communication pathways and regulation at the level of the whole organism and local levels, in both healthy persons and patients with allergic rhinitis based on an allergic inflammatory process. This review focuses on a new research paradigm devoted to neuronal-immune cell units, which are involved in allergic inflammation in the nose and neuroimmune control of the nasal mucociliary immunologically active epithelial barrier. The categorization, cellular sources of neurotransmitters and neuropeptides, and their prevalent profiles in constituting allergen tolerance maintenance or its breakdown are discussed. Novel data on the functional structure of the nasal epithelium based on a transcriptomic technology, single-cell RNA-sequencing results, are considered in terms of neuroimmune regulation. Notably, the research of pathogenesis and therapy for atopic allergic diseases, including recently identified local forms, from the viewpoint of the tridirectional interaction of the neuroimmune network and discrete neuronal-immune cell units is at the cutting-edge.