B cells: The many facets of B cells in allergic diseases.

B cells play a key role in our immune system through their ability to produce antibodies, suppress a proinflammatory state, and contribute to central immune tolerance. We aim to provide an in-depth knowledge of the molecular biology of B cells, including their origin, developmental process, types and subsets, and functions. In allergic diseases, B cells are well known to induce and maintain immune tolerance through the production of suppressor cytokines such as IL-10. Similarly, B cells protect against viral infections such as severe acute respiratory syndrome coronavirus 2 that caused the recent coronavirus disease 2019 pandemic. Considering the unique and multifaceted functions of B cells, we hereby provide a comprehensive overview of the current knowledge of B-cell biology and its clinical applications in allergic diseases, organ transplantation, and cancer.

Allergen-specific immunotherapy practices and course of coronavirus disease 2019 (COVID-19) in patients during COVID-19.

BACKGROUND: Allergen-specific immunotherapy (AIT) is accepted as the only disease-modifying therapy for IgE-mediated allergic airway diseases and hymenoptera venom allergy. AIT requires repeated contact between patient and physician or nurse in the hospital. Because it is a long-term treatment, compliance is essential issue to obtain maximal efficacy. Coronavirus disease 2019 (COVID-19) pandemic reshaped doctor-patient interaction and pattern of hospital admissions. OBJECTIVE: We aimed to determine the possible changes in the administration of AIT and associated factors, in addition to the characteristics of patients diagnosed with COVID-19 infection. METHODS: Adult patients who underwent AIT for hymenoptera venom allergy, allergic rhinitis or allergic asthma between 11 March 2020 and 31 January 2021 were included in our retrospective study. Perennial and preseasonal AIT practices were evaluated. We identified patients with COVID-19 infection among the ones who received AIT. RESULTS: The mean age of 215 patients was 37.8±11.9 years and 52.1% of the patients were female. In our study, 35.4% of perennial AIT patients did not continue treatment after the COVID-19 pandemic, and the cause was patient-related in 66.7% of the cases. Compliance was 70.7% in patients receiving perennial AIT. The highest compliance rate for AIT was for venom allergy (86.5%). Thirty-four patients (15.8%) were diagnosed with COVID-19 infection. No mortality due to COVID-19 infection was observed in those who underwent AIT. CONCLUSION: COVID-19 pandemic has reduced compliance to AIT. Compliance was higher in venom immunotherapy than in aeroallergens. Severe COVID-19 infection and COVID-19 related death were not observed in patients receiving AIT.

Asthma and COVID-19: Аn overview of the guidelines for the management of asthma patients during the COVID-19 pandemic

The emergence of a new disease COVID-19 (coronavirus disease 2019), caused by the coronavirus named SARS-CoV-2, has significantly changed the usual interaction pattern between a doctor and a patient. Previous large studies have identified risk factors for a severe course of COVID-19, including old age, hypertension, diabetes, cardiovascular diseases, and chronic obstructive pulmonary disease. However, asthma and respiratory allergy have not been identified as risk factors for the severe disease. These factors give clues to the pathogenesis of COVID-19, approaches to the controller medications, target therapy, allergen-specific immunotherapy (ASIT) in patients with various phenotypes and endotypes of asthma during the pandemic. The purpose of this review is to summarize the currently available knowledge about SARS-CoV-2, T2-endotype of asthma, eosinophilic inflammation. The article provides an overview of the data from studies of COVID-19 patients with asthma, the main recommendations of the Global Initiative for Asthma (2021) and the Ministry of Health of the Russian Federation. It shows that targeting the endotypes and phenotypes of asthma can influence the management of COVID-19 patients with asthma. The influence of the imbalance of the immune system, pro-inflammatory cytokines, and effector cells in patients with asthma on the development and progression of COVID-19 is considered. Recommendations are given for the controller medications, targeted therapy, allergen-specific immunotherapy during the pandemic. Conclusion. The current recommendations for asthma treatment, based on the latest research of COVID-19, deepen our understanding of the course of COVID-19 in patients with different phenotypes and endotypes of asthma, approaches to traditional methods of treating asthma according to clinical guidelines during the pandemic. © 2021 Medical Education. All rights reserved.

Venom immunotherapy during COVID-19 pandemic: Experience from a University Allergy Center in Northern Italy.

During the ongoing pandemic of Coronavirus Disease 2019 (COVID-19) allergic patients need to continue their constant and proper treatment, including allergen-specific immunotherapy. These patients are expected to be at a higher risk for exacerbation of lung inflammation during viral infection. We investigated the putative interplay existing between allergen-specific immunotherapy and COVID-19 infection in a Hymenoptera venom-allergic population. We evaluated the frequency and severity of COVID-19 infection in a cohort of 211 subjects referring to our center for the regular administration of venom immunotherapy (VIT). Our result showed that the median age of our cohort is similar to the one that in our region has been associated with a high incidence of COVID-19 infection, increased hospitalization, and mortality rates. We reported only an isolated positivity of COVID-19 in the overall group; whereas none suffered from upper airway symptoms associated with COVID-19 (fever, cough, dyspnoea, sore throat, anosmia, and/or ageusia). Even though the demographic characteristics pose a substantial risk for such a population, we suggest that a regular administration of VIT may help in the development of an immunological milieu able to down modulate the Th1/Th17 environment that has been linked to inflammatory manifestations of COVID-19. To the best of our knowledge, this is the first description of the incidence of COVID-19 infection in Hymenoptera venom allergic patients treated with VIT, suggesting indirectly that venom immune tolerance-inducing treatment may be capable of reducing the aberrant inflammatory response induced by the virus in this specific population.