CLINICAL SIGNIFICANCE OF IgG ANTIBODIES IN THE DIAGNOSIS OF ALLERGIC CONDITIONS AND CONTROL OF ALLERGEN-SPECIFIC IMMUNOTHERAPY. Review
Authors: Marushko I.V. , Halushko B.L. , Yuriev S.D. , Hyshchak T.V. , Moskovenko E.D . 
Published: January 2022

Relevance. In recent years, there has been a significant increase in the number of allergic diseases among the population. In patients with allergic conditions in the presence of indications, allergists are increasingly prescribing allergen-specific immunotherapy. This necessitates the search for new accurate tools and markers for forecasting and evaluating its effectiveness. At present, methods of monitoring the effectiveness of allergen-specific immunotherapy are largely based on the assessment of the clinical condition of patients through questionnaires and provocative trials. Promising in this direction is the study of the role of IgG4 in the development of tolerance to allergens, and the mechanisms by which this protective function is realized. Particularly important are pathological reactions to food, which can be mediated not only by IgE, but also by IgG-associated circulating immune complexes. Therefore, it is important to study the role of IgG in the development of food intolerance and the possibility of using an elimination diet based on the identification of specific IgG to food in such patients.
Objective: to summarize the literature and the results of own studies of IgG antibodies in the diagnosis of allergic conditions and control of allergen-specific immunotherapy.
Methods. Search in international scientometric databases PubMed, Scopus, etc. by keywords. Search depth - 10 years (2011-2021). IgG determination was performed by FOX test (Food Xplorer Macro Array Diagnostics GmbH, Austria), enzyme linked immunosorbent assay (ELISA).
Results. A review of the literature revealed studies that found an association between increases in IgG4 levels and a decrease in allergy in patients receiving allergen-specific therapy. Also, a significant number of studies attribute the important role of IgG in the development of food intolerance, in which a high-efficiency elimination diet based on excluded products to which specific IgG is detected.
Conclusions. IgG is an antibody with unique biological properties, which plays an important role in the mechanisms of occurrence and course of a number of diseases, including those related to allergies. As a result, IgGs have great diagnostic potential. The existing problem of lack of objective diagnostic methods that would assess the effectiveness of allergen-specific immunotherapy in the early stages and predict the patient's condition in the future, could be solved by introducing the determination of IgG4 levels in general clinical practice. It is also important to determine food-specific IgG in patients with food intolerance, the content of which we determined using the FOX test. Various studies have established the effectiveness of a diet based on the elimination from the diet of foods to which specific IgG has been detected. Compared to the uncontrolled intake of symptomatic drugs and various unjustified dietary restrictions, this diet has significant therapeutic and economic benefits.