allergens

Allergen immunotherapy (AIT) is the unique curative treatment to help allergic patients to get over their allergies. With a personalized approach, AIT is the best example of precision medicine. After a century of intensive studies and innovative discoveries, allergists have in their hands many tools to orchestrate the best strategy to re-educate the hypersensitive immune systems that decrease the quality of life of their patients. This review describes both the historical and the promising acquisitions in this field, focusing the biochemical and Bioengineering tools that render an allergen more suitable for a secure, convenient and effective immunotherapy.

By researching the factors related to exposure to indoor and outdoor allergens, such seasons, climate changes and particulate matter, allergists can screen the sensitization profile of individuals according to their exposures and conduct preventive treatment and individualized immunotherapy. Molecular allergology has improved aerobiological screening of allergenic components toward more specific results on allergic exposure, sensitization, and symptoms [1,2]. The Enzyme-Linked Immunosorbent Assay (ELISA) is a colorimetric enzyme immunoassay technique used to quantify soluble substances such as proteins, peptides, antibodies, and hormones. Due to its high sensitivity and specificity, ELISA can quantify substances at low concentrations, such as allergens [3].

Background: In France, from 30% to 35% of children suffer from multiple food allergies (MFA). The gold standard to diagnosis a food allergy is the oral food challenge (OFC) which is conducted in a hospital setting due to risk of anaphylaxis. The aim of this study was to evaluate an algorithm to predict OFCs at low risk of anaphylaxis that could safely be performed in an office-based setting. Methods: Children with MFA and at least one open OFC reactive or non-reactive to other allergens were included. The algorithm was based on multiple clinical and biological parameters related to food allergens, and designed mainly to predict “low-risk” OFCs i.e., practicable in an office-based setting. The algorithm was secondarily tested in a validation cohort. Results: Ninety-one children (median age 9 years) were included; 94% had at least one allergic comorbidity with an average of three OFCs per child. Of the 261 OFCs analyzed, most (192/261, 74%) were non-reactive. The algorithm failed to correctly predict 32 OFCs with a potentially detrimental consequence but among these only three children had severe symptoms. One hundred eighty-four of the 212 “low-risk” OFCs, (88%) were correctly predicted with a high positive predictive value (87%) and low negative predictive value (44%). These results were confirmed with a validation cohort giving a specificity of 98% and negative predictive value of 100%. Conclusion: This study suggests that the algorithm we present here can predict “low-risk” OFCs in children with MFA which could be safely conducted in an office-based setting. Our results must be confirmed with an algorithm-based machine-learning approach.

Introduction: Allergen immunotherapy is the only targeted therapy that can modify the natural course of allergic diseases. In pediatric patients, SCIT with aeroallergens is an effective treatment and should be considered as a preventive strategy in the treatment of allergic diseases, even though one of the major concerns about it is its safety. The main purposes of this study were to assess the safety of SCIT ultra-rush schedules with polymerized extracts in a pediatric population and to determine the impact of the COVID-19 pandemic on the safety and time of administration of subcutaneous immunotherapy among pediatric patients.Methods: A retrospective medical records review of patients under 18 years of age undergoing SCIT was made and re-scheduling due to restrictions imposed by the COVID-19 pandemic was recorded. Results: A total of 192 pediatric patients were included. Fifty-nine (31%) had local reactions and systemic reactions were not reported. In March 2020, the first case of COVID-19 was diagnosed in Portugal and all non-urgent appointments and procedures were postponed. In our group of pediatric patients, 43 (22%) were referred to primary care, 38 (20%) stopped AIT definitively and 111 (58%) maintained administrations in the hospital. Only 2 (2%) of them had reactions upon reinitiation. Conclusion: In this study, the ultra-rush protocol using polymerized extracts was safe in pediatric patients. Although the effectiveness of AIT may be compromised due to prolonged suspension of the treatment, it is important to note that despite longer interruptions, administrations may continue without compromising safety, maintaining shorter visits and a lower number of injections.