Wojciech Feleszko

and 23 more

Multisystem inflammatory syndrome in children (MIS-C) is a rare, but severe complication of coronavirus disease 2019 (COVID-19). It develops approximately four weeks after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and involves hyperinflammation with multisystem injury, commonly progressing to shock. The exact pathomechanism of MIS-C is not known, but immunological dysregulation leading to cytokine storm plays a central role. In response to the emergence of MIS-C, the European Academy of Allergy and Clinical Immunology (EAACI) established a task force (TF) within the Immunology Section in May 2021. With the use of an online Delphi process, TF formulated clinical statements regarding immunological background of MIS-C, diagnosis, treatment, follow-up, and the role of COVID-19 vaccinations. MIS-C case definition is broad, and diagnosis is made based on clinical presentation. The immunological mechanism leading to MIS-C is unclear and depends on activating multiple pathways leading to hyperinflammation. Current management of MIS-C relies on supportive care in combination with immunosuppressive and/or immunomodulatory agents. The most frequently used agents are systemic steroids and intravenous immunoglobulin. Despite good overall short-term outcome, MIS-C patients should be followed-up at regular intervals after discharge, focusing on cardiac disease, organ damage, and inflammatory activity. COVID-19 vaccination is a safe and effective measure to prevent MIS-C. In anticipation of further research, we propose a convenient and clinically practical algorithm for managing MIS-C developed by the Immunology Section of the EAACI.

Lisa Hung

and 15 more

Background: Food allergy affects up to 8% of the pediatric population. Despite ongoing efforts, treatment options remain limited. Novel models of food allergy are needed to study response patterns downstream of IgE-crosslinking and evaluate drugs modifying acute events. Here, we report a novel human ex vivo model that displays acute, allergen-specific, IgE-mediated smooth muscle contractions using precision cut intestinal slices (PCIS). Methods: PCIS were generated using gut tissue samples from children who underwent clinically indicated surgery. Viability and metabolic activity were assessed from 0-24h. Distribution of relevant cell subsets was confirmed using single cell nuclear sequencing. PCIS were passively sensitized using plasma from peanut allergic donors or peanut-sensitized non-allergic donors, and exposed to various stimuli including serotonin, histamine, FcɛRI-crosslinker and food allergens. Smooth muscle contractions and mediator release functioned as readouts. A novel program designed to measure contractions was developed to quantify responses. The ability to demonstrate the impact of antihistamines and immunomodulation from peanut oral immunotherapy (OIT) was assessed. Results: PCIS viability was maintained for 24h. Cellular distribution confirmed the presence of key cell subsets including mast cells. The video analysis tool reliably quantified responses to different stimulatory conditions. Smooth muscle contractions were allergen-specific and reflected the clinical phenotype of the plasma donor. Tryptase measurement confirmed IgE-dependent mast cell-derived mediator release. Antihistamines suppressed histamine-induced contraction and plasma from successful peanut OIT suppressed peanut-specific PCIS contraction. Conclusion: PCIS represent a novel human tissue-based model to study acute, IgE-mediated food allergy and pharmaceutical impacts on allergic responses in the gut.

Marek Jutel

and 68 more

Ioana Agache

and 29 more

Akash Kothari

and 2 more

Article Type: News and Views: Groundbreaking Discoveries in ImmunologyTitle: Emollients for the prevention of atopic dermatitisAuthors: Akash Kothari1(https://orcid.org/0000-0003-1980-161X), Arielle Locke2,Thomas Eiwegger1,3,4(https://orcid.org/0000-0002-2914-7829)1Translational Medicine Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada2Department of Medicine, National University of Ireland, Galway, Ireland3Division of Immunology and Allergy, Food Allergy and Anaphylaxis Program, The Department of Pediatrics, Hospital for Sick Children, Toronto, Ontario, Canada4Department of Immunology, Faculty of Medicine, University of Toronto, Toronto, Ontario, CanadaCorrespondence to: Thomas Eiwegger, MD, Division of Immunology and Allergy, Food Allergy and Anaphylaxis Program, The Department of Paediatrics, Hospital for Sick Children, 555 University Ave, Toronto, Canada, E-mail: [email protected], Tel.: +1 416-813-7654 ext. 1862Conflicts of Interest: AK and AL have nothing to disclose. TE reports to act as local PI for company sponsored trials by DBV and sub-investigator for Regeneron, holds grants from Innovation Fund Denmark, CIHR outside the submitted work. He is Co-Investigator or scientific lead in three investigator initiated oral immunotherapy trials supported by the Food Allergy and Anaphylaxis Program SickKids and serves as associate editor for Allergy. He/his lab received unconditional/in-kind contributions from Macro Array Diagnostics and an unrestricted grant from ALK. He holds advisory board roles for ALK.Financial support: This work was supported by The Hospital for Sick Children, The Food Allergy and Anaphylaxis Program at The Hospital for Sick Children, and The Dr Lorus J And Dr Margery J Milne Scholarship from Victoria University at the University of Toronto.Statement of Author Contribution: All authors critically reviewed the original articles (references 6 and 7) and wrote the News & Views: Groundbreaking discoveries in Immunology article. All authors contributed, revised, edited, and approved the final version of the manuscript as submitted and agreed to be accountable for all aspects of the work.Keywords: emollient, atopic eczema, infancyAbbreviations : food allergy, FA; filaggrin gene, FLG; atopic dermatitis, AD; transepidermal water loss, TEWL; Barrier Enhancement for Eczema Prevention, BEEP; Preventing Atopic Dermatitis and Allergies, PreventADALL