Autoinflammatory undifferentiated syndrome

Abstract

Identification of primary immunodeficiencies (PID), distinction of their nosological forms and timely admoinistered therapy for this disorders frepresent topical problems of modern immunology. According to the PID registry of the National Association of Experts in the Field of Primary Immunodeficiencies (NAEPID), as of 2021, 3617 cases of this disease were diagnosed in Russian Federation (RF). The prevalence of PID in Russian Federation is 2.48 per 100,000 population. Currently, autoinflammatory syndromes (AIS) comprise rare, genetically determined disorders. According to the NAEPID registry data, of the PID register, 541 cases of autoinflammatory syndrome (AIS) were registered in the Russian Federation (2021). Timely diagnosis of AIS is especially important in young children who have similar phenotypic signs, in order to reduce the number of deaths and prevent disability. According to the PID registry, the median diagnostic delay in Russia is 27 months. The purpose of this work is to update information about the autoinflammatory syndrome that clinicians may encounter, e.g., pediatricians, rheumatologists, hematologists and other specialists. This syndrome requires a complex differential diagnostic algorithm for clinicians and is often subject to multidisciplinary approach, involving specialists of different profile. This article describes a clinical case of a 3-year-old child S. with a diagnosis of Primary immunodeficiency: autoinflammatory syndrome, undifferentiated. The patient was diagnosed since the age of 5 months, when periodic rises in body temperature to febrile values were registered once a month. Later on, the fever episodes were observed 2 times a month. The diagnosis was made at the place of residence as secondary immunodeficiency virus-associated state (CMV infection). CMV viremia was canceled against the background of ongoing treatment, but the inflammatory attacks persisted. Molecular genetic studies did not reveal any defects. In view of poor response to NSAID therapy and prednisone prescribed at a dose of 1-1.5 mg/kg/day, he was admitted to the Dmitry Rogachev Research Medical Cemter. The child was finally diagnosed with PID, and therapy was initiated with a selective competitive inhibitor of TNFa etanercept at a dose of 0.8 mg/kg/day once a week. Hence, the autoinflammatory syndrome in children is difficult to diagnose and select therapy, and it may be unfavorable prognostically.