Allergic diseases are one of the most urgent problems of practical medicine. According to statistics of the World Health Organization, about 40% of the world's population suffers from allergies. Molecular allergy diagnostics (MA) is currently the most useful patient selection method for prescribing allergen-specific immunotherapy (ASIT), determining cross-reactivity, and the severity of the reaction associated with various allergens. Molecular allergic diagnosis has advantages for the diagnosis of patients with allergic symptoms - asthma, pollinosis, eczema, hives, gastrointestinal symptoms, oral allergic syndrome, or anaphylaxis. It is based on the choice of individual allergens by a doctor or the use of microarrays and offers a large amount of information related to the IgE profile of sensitized patients. The most effective method of treatment for allergic diseases is allergen-specific immunotherapy, which affects all pathogenetic links of the allergic process and has a long-term preventive effect after the completion of treatment courses. The aim of the article is to study the prevalence of IgE reactivity to major recombinant allergens on the background of the types of allergen-specific immunotherapy. In the course of the work, patients were examined by allergic molecular diagnostics. The article shows the results of a comparative study of the presence of specific IgE in the serum of patients with confirmed sensitization to major recombinant allergens: wormwood Art vl, Art v3, timothy Phl p1, Phl p5 and birch Bet v1 for a three-year period. The data obtained confirm the high efficiency of sublingual immunotherapy (SLIT) and its positive effect on the reduction of sensitization in patients with pollinosis compared with the results of the parenteral immunotherapy group (sublingual immunotherapy).