Bronchial asthma resistant to pharmacotherapy: why there is no response to the treatment?

Despite the obvious and simple diagnosis, in practice we meet patients who do not respond to standard therapy. Why does drug resistance occur? The answer to this question is not unambiguous and requires careful investigation in each clinical case. Here we present a clinical case of a patient with bronchial asthma, who had no bad habits and occupational hazards and received adequate drug therapy. However, her condition worsened from attack to attack. Whole exome sequencing by NGS allowed us to determine the spectrum of pathogenic mutations which contribute to the pathological process and drug resistance. Atopy due to dysfunction of filaggrin gene (FLG) triggered the disease and supported the pathological process that led to bronchial asthma. Furthermore, the patient’s body is not able to neutralize the bacterial flaggelin. The inflammatory response is reduced due to а Toll-like receptor 5 (TLR5) deficiency. This is one of the mechanisms underlying development of allergic bronchial asthma. In addition, the patient has reduced cross-presentation of antigens by dendritic cells, that is, a reduced immune response in the absence of infection, due to the complete loss of UNC93B1 gene function. Conclusion. Thus, an atopic reaction based on reduced adaptive immunity led to severe IgE allergy and torpid course of bronchial asthma. This conclusion supports atopic sensitization as the target for therapeutic action and the main core of pathological processes. For this purpose, we used a monoclonal antibody omalizumab that is capable of binding and reducing the amount of IgE. Targeted treatment of bronchial asthma made it possible to interrupt the symptoms and achieve complete remission.

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