α-Gal and other recent findings that have informed our understanding of anaphylaxis

Objective: To summarize the current understanding of anaphylaxis, with an emphasis on major findings that have been reported within the last 10 years. Data Sources: Queries relating to anaphylaxis, immunoglobulin E (IgE), and mast cells were conducted with PubMed and Google Scholar, searching for primary articles and review papers. Study Selections: We focused on articles written in English and which were reported in major allergy and immunology journals. Results: Anaphylaxis represents an extreme manifestation of a form of allergic immunity that appears to have evolved to protect against toxic threats that present at skin and mucosal barriers. The factors that have contributed to a rise in anaphylaxis are increasingly appreciated to relate to changes in hygiene and microbial ecology that have occurred with industrialization. Induction of allergen-specific IgG4 is often part of the allergic response and is associated with protection against anaphylaxis. The recognition of the alpha-Gal syndrome suggests that carbohydrates can be epitopes that are relevant to anaphylaxis and that IgE-mediated reactions do not always occur immediately. Conclusion: Our understanding of anaphylaxis has advanced significantly over the past 10 years. It is anticipated that ongoing research will build on this foundation to further advance our knowledge of anaphylaxis and also translate into clinically meaningful therapies. (C) 2019 Published by Elsevier Inc. on behalf of American College of Allergy, Asthma & Immunology.