Animal Models of IgE Anaphylaxis

Simple Summary Anaphylaxis is the most severe form of allergic reactions and can be life-threatening. It is very difficult to study the mechanisms underlying anaphylaxis in humans since these events are rare and often lethal. Therefore, animal models have been established. Mice and rats are mostly used since their biological parameters, such as temperature drop, behavioral changes, and blood or cell biomarkers, can be easily measured in the laboratory. These animals can also be genetically modified to express human proteins and cell functions. Different animal models have been established to replicate as closely as possible the natural route of sensitization to the allergen and to trigger anaphylaxis in animals. These animal models have deepened our knowledge on human anaphylaxis with certain limitations, as discussed in this review. Allergies and atopy have emerged as significant public health concerns, with a progressively increasing incidence over the last two decades. Anaphylaxis is the most severe form of allergic reactions, characterized by a rapid onset and potentially fatal outcome, even in healthy individuals. Due to the unpredictable nature and potential lethality of anaphylaxis and the wide range of allergens involved, clinical studies in human patients have proven to be challenging. Diagnosis is further complicated by the lack of reliable laboratory biomarkers to confirm clinical suspicion. Thus, animal models have been developed to replicate human anaphylaxis and explore its pathophysiology. Whereas results obtained from animal models may not always be directly translatable to humans, they serve as a foundation for understanding the underlying mechanisms. Animal models are an essential tool for investigating new biomarkers that could be incorporated into the allergy workup for patients, as well as for the development of novel treatments. Two primary pathways have been described in animals and humans: classic, predominantly involving IgE and histamine, and alternative, reliant on IgG and the platelet-activating factor. This review will focus essentially on the former and aims to describe the most utilized IgE-mediated anaphylaxis animal models, including their respective advantages and limitations.