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.

[Mexican consensus on fractional exhaled nitric oxide (FeNO) in asthma 2020]. / Consenso mexicano en relación con la fracción exhalada de óxido nítrico (FeNO) en asma 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.

La fracción exhalada de óxido nítrico (FeNO) se relaciona con el nivel de inflamación eosinofílica en las vías aéreas y los niveles de interleucina-13, por lo que podría ser una herramienta diagnóstica y de seguimiento en el asma. Se convocó un grupo de trabajo integrado por neumólogos, expertos en fisiología de la respiración y alergólogos, con la finalidad de establecer criterios para el uso de la FeNO en asma en México. Mediante un método Delphi simplificado y discusión grupal, se consensaron varios puntos clave en relación con el uso de la FeNO. Sugerimos que la medición de la FeNO sirve para el diagnóstico de asma en clínicas especializadas, tanto en niños como adultos, así como para determinar el nivel de tratamiento con corticosteroides. En asma grave, recomendamos la FeNO para la endotipificación, detectar la mala adherencia terapéutica, el subtratamiento y el riesgo de crisis. Sugerimos su uso para determinar el nivel de tratamiento con corticosteroides e identificar pacientes con riesgo de tener una pérdida de la función pulmonar. También la recomendamos en el adulto para mejorar la elección de medicamentos biológicos y, en este contexto, solo la sugerimos en casos selectos en niños.

Correlación de las concentraciones de IgE sérica total y pruebas cutáneas / IgE levels of skin test correlation

Se realizó un estudio prospectivo para conocer la correlación entre las concentraciones de IgE total sérica y las pruebas cutáneas por escarificación en 300 pacientes con diagnóstico clínico de rinitis alérgica y asma bronquial extrínseca. La correlación de las concentraciones de IgE aportó un índice de variabilidad de 15.6 por ciento con una sensibilidad diagnóstica de 0.86, lo que confirma que este estudio es indispensable para el diagnóstico, manejo y control del paciente atópico