Searching for predictive biomarkers of allergen-specific immunotherapy efficacy based on modern concepts of its mechanisms

Allergen-specific immunotherapy is the main pathogenetically substantiated method for the treatment of allergic diseases. It not only leads to a decrease in the clinical symptoms severity, but also has a disease-modifying effect, prevents the progression of the disease, prevents the development of asthma and the spreading of sensitization. Immunological tolerance driven by the allergen-specific immunotherapy is mediated by a complex interaction between various cells of innate and adaptive immunity. Despite the fact that the main mechanisms of allergen-specific immunotherapy have been described to date, the understanding of these processes becomes more detailed at the cellular, molecular and epigenetic levels every year. In turn, a deep understanding of the mechanisms underlying the developing and maintenance of tolerance to allergens during allergen-specific immunotherapy can help reveal predictive biomarkers of efficacy. These biomarkers could streamline the selection of patients by identifying the responders to allergen-specific immunotherapy. This review represents current concepts of the allergen-specific immunotherapy mechanism on various stages of the allergic process. Furthermore, supposed predictive biomarkers of the efficacy are described, taking into account promising directions of research in this area.