Experience with a Genetically Engineering Biological Agent in a Child with Hypereosinophilic Syndrome Following Coronavirus Infection: Literature Review and Case Report

Hypereosinophilic syndrome (HES) is a heterogeneous group of disorders characterized by tissue eosinophilic infiltration and a wide spectrum of clinical manifestations. The issue of pathogenetic therapy for this condition remains unresolved, as some patients are refractory to conventional treatment. Case report . This article discusses the main challenges of differential diagnosis and current approaches to the treatment of HES in pediatric practice, and presents a rare clinical case of primary HES in a 14yearold girl. After a thorough diagnostic workup and confirmation of the diagnosis, the patient received systemic glucocorticoid therapy, which produced a temporary effect. However, due to the development of a severe exacerbation upon attempted withdrawal of hormonal therapy, treatment with mepolizumab — a humanized monoclonal antibody against the interleukin5 receptor — was initiated. Conclusion . The management of patients with HES often presents significant difficulties due to the polymorphism of clinical manifestations, the need to rule out a wide range of diseases, and possible refractoriness to standard therapy. The usage of this genetically engineered biological agent demonstrated high efficacy, enabling the patient to overcome glucocorticoid dependence and prevent the development of glucocorticoid-related adverse effects.