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.

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.

[Logistic precautions in preparation and administration of allergen immunotherapy during the COVID-19 pandemic in Mexico]

La pandemia actual de COVID-19 ha representado un reto mayúsculo para la sociedad y la comunidad médica, no solo por su alta contagiosidad sino por la variabilidad de las manifestaciones clínicas y su comportamiento impredecible bajo diferentes contextos sanitarios. Ante ello, las medidas preventivas específicas son relevantes para evitar o disminuir contagios entre pacientes y personal de las unidades de salud, considerando que el periodo presintomático durante el cual el individuo contagiado ya puede transmitir el virus varía entre cinco y seis o hasta 14 días, según datos de la Organización Mundial de la Salud. Además, un paciente infectado puede estar asintomático, incluso, algunas personas después de haber padecido COVID-19 pueden continuar expulsando virus por algunos días más después de recuperarse.

[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.

[Knowledge of asthma: educational intervention with the 2014 GINA guide in primary care physicians]

BACKGROUND

Asthma is a public health problem in the world, so updating the guidelines for the diagnosis and treatment of asthma is based primarily on the practice of primary care physicians. Educational interventions are useful for increasing knowledge.

OBJECTIVE

To compare the level of knowledge of asthma before and after an educational intervention.

METHODS

A quasi-experimental prospective study was conducted in general and family practitioners and pediatricians who attended a training workshop on general aspects of asthma and current guidelines for diagnosis and treatment (GINA 2014). A questionnaire consisting of 11 multiple choice questions relating to fundamental aspects of the disease and diagnosis, classification, treatment and management of attacks, was used in two assessments, baseline and post-intervention.

RESULTS

A total of 178 patients participated in the study, with knowledge pre-intervention at 25.5 points and post-intervention at 97.5 points on a scale of 100, with p < 0.05.

CONCLUSION

Educational interventions are inexpensive and effective tools to increase the knowledge of health professionals, and they have an impact on improving patient care.

[Food allergy diagnosis in patients with elimination diet history. Preliminary report]

BACKGROUND

Food allergy diagnosis is performed by a double blind placebo controlled challenge; however, in a lot of patients, it is only based on clinical history, skin prick tests, or parents' perception. There is a high frequency of elimination diets without an adequate approach.

OBJECTIVES

To analyze the results of diagnostic tests in a group of children with elimination diet-based on suspected food allergy and verify such studies with double blind placebo-controlled test challenge.

MATERIAL AND METHOD

An observational, analytical and prospective study was done in a group of patients with elimination diet for suspected food allergy. We performed prick test, Prick-to-Prick test and patch test and the positive ones were verified by double-blind placebo-controlled challenge.

RESULTS

Fourty-three patients were included within a total of 1,935 tests. Both approach for immediate and late sensitivity had not statistically significant relationship between a positive test and the elimination of food. Until now, we had 4 (8%) positive challenges out of 50.

CONCLUSIONS

The frequency of allergy proved by double-blind placebo-controlled test in 50 challenges was of 8% (4/50), thus, in the preliminary report we found a high frequency of elimination diets without adequate support. It is very important that food allergy diagnosis is accurate and based on an appropriate approach; since the implementation of an elimination diet in pediatric population can have a negative influence on their growth and development.

Reporte preliminar del abordaje diagnóstico de alergia alimentaria en pacientes con antecedente de dieta de eliminación

Antecedentes: el diagnóstico de alergia alimentaria se realiza idealmente con reto doble ciego controlado con placebo; sin embargo, en muchas ocasiones sólo se basa en la historia clínica, en las pruebas cutáneas o, incluso, en la percepción de los padres. Con gran frecuencia se prescriben dietas de eliminación sin el abordaje adecuado.Objetivos: analizar los resultados de las pruebas diagnósticas de alergia alimentaria en un grupo de niños con dieta de eliminación y verificar esos estudios con la prueba de reto doble ciego.Material y método: estudio observacional, analítico, prospectivo, efectuado en un grupo de pacientes con dieta de eliminación por sospecha de alergia alimentaria. Se realizaron pruebas por punción, Prick-to-Prick y de parche a todos los pacientes y posteriormente se verificó la positividad de esas pruebas mediante reto doble ciego controlado con placebo.Resultados: se incluyeron 43 pacientes con un total de 1,935 pruebas. En el abordaje para sensibilidad inmediata y tardía no se encontró ninguna relación estadísticamente significativa entre la positividad de la prueba y la eliminación del alimento. Al momento se han realizado 50 retos, de los que 4 fueron positivos (8%).Conclusiones: la frecuencia de alergia comprobada por reto doble ciego controlado con placebo en 50 retos fue de 8% (4/50), por lo que en este reporte preliminar encontramos una alta frecuencia de eliminación de alimentos sin el sustento adecuado. Es muy importante que el diagnóstico de alergia alimentaria sea acertado y se base en el abordaje adecuado, porque la implementación de una dieta de eliminación en una población muy vulnerable, como los pacientes pediátricos, es de suma importancia y puede influir de manera negativa en su crecimiento y desarrollo.