Résumé
Background: severe infectious diseases are a prominent cause of morbidity and mortality in high-income countries and preferentially affect predisposed children, revealing a primary immunodeficiency disease (PID). Here we evaluated the prevalence of PID after a systematic immunological screening in children admitted for a severe infection in a pediatric intensive care unit.Methods and results: we carried out a prospective longitudinal study at Montpellier’s University Hospital from January 2018 to December 2020. All children aged 1 month to 16 years, admitted in pediatric intensive care unit due to an identified infection, other than Respiratory Syncytial Virus related infection, were included. Clinical evaluation and immunological explorations were scheduled at 3 months and 1-year after onset of infection, and genetic exploration was oriented by the clinical presentation.Results: among the 46 children included, 3 had a confirmed PID which represented a prevalence of 6.52% (95% CI [1.4; 17.9]). At 3 months, 40 children (86.95%) had immunological anomalies. At 1-year, abnormalities were confirmed in 4 of the 17 children having a second blood test (23.53%). Six patients had oriented genetic test (sanger and NGS panel), and 9 trio genetics analysis were conducted.Conclusion: systematic investigation of primary immunodeficiency diseases after a severe infection should be considered to improve early detection and treatment.