Anti-interferon α-antibodies in pediatric patients with COVID-19 and long COVID.

Introduction: The involvement of neutralizing antibodies against type I interferon (IFN-I) in the development of severe coronavirus disease 2019 (COVID-19) in adult patients has been well documented. However, the role of anti-IFN-α autoantibodies, especially non-neutralizing types, remains underexplored, especially in children. Our study aimed to determine the frequency of antibodies against IFN-α in children with COVID-19 and long COVID, as well as their potential role in the development of long COVID. Material and methods: The study included 78 children aged 1 to 17 years with a documented history of COVID-19 from September 2022 to August 2023. All patients were divided into three groups: hospitalized with COVID-19, hospitalized with long COVID symptoms, and monitored in an outpatient care department for mild COVID-19 or symptoms of long COVID. Human anti-IFN-α antibodies were detected using enzyme-linked immunosorbent assay. Results: Binding anti-IFN-α antibodies were detected in 2/78 (2.6%) children with COVID-19 of varying severity. One patient with anti-IFN-α antibodies had comorbidities (obesity, allergic rhinitis) and critical COVID-19 pneumonia (SpO Conclusions: Further studies in larger cohorts are needed to assess the role of anti-IFN-α antibodies (both neutralizing and non-neutralizing) in the development of long COVID symptoms, to understand their clinical significance, and to examine their dynamics over time.