Periodontitis and Inflammation in Children With Down Syndrome/Trisomy 21: Study on Biological Samples

Overview

Since 2018, the Chicago Classification of Periodontal Diseases and Conditions, has listed Down syndrome (DS)/trisomy 21 (T21) as a systemic disease with periodontal implications. Numerous studies report an increased prevalence and severity of periodontitis in DS/T21 individuals under the age of 35. Approximately 35% of adolescents with DS show early signs of alveolar bone loss. However, very few studies have examined the role of immune deficiency in DS/T21 patients in the pathogenesis of periodontitis. Indeed, periodontitis induced by bacterial plaque is virtually non-existent in the paediatric population, leaving the field to systemically-induced periodontitis. The investigators hypothesize that specific neutrophil phenotypes in DS/T21 patients are key to explaining the rapid progression to periodontitis. Investigator's primary objective is to characterize the different oral and blood neutrophil subtypes in DS/T21 children with gingival inflammation. Investigator's secondary objective is to assess the involvement of different neutrophil subtypes in early periodontitis in children with DS/T21.

It's a cross-sectional, monocenter, prospective, open-label, non-randomized case control study to collect saliva and serum samples as part of the patient's routine care in oral medicine department to form a biological collection. Patients will be recruited in the oral medicine department of AP-HP Charles Foix hospital (Ivry/Seine) by periodontists in 2 groups (CASES: Group 1 for children with DS/T21 divided into 2 subgroups according the periodontal health, and CONTROLS: Group 2 divided into 4 subgroups according to the systemic and periodontal health) Inclusion period is 12 months. There is no specific follow-up due to the research. Assessment criteria: * Primary criteria: Neutrophil subtypes analysis based on co-expression of neutrophil function markers from a panel of 24 markers by flow cytometry. * Secondary criteria: assessment of neutrophil sub-types present in the patient's saliva and study of the correlation within blood neutrophils, during periodontal health, gingivitis and periodontitis.