periodontitis and inflammation in children with down syndrome/trisomy 21: study on biological samples

Conditions: Periodontitis; Trisomy 21

Summary: 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.

Eligibility criteria:
inclusion criteria: common to all groups: * age: 3 to 12 * patient affiliated to a social security program, beneficiary not covered by the ame. * legal representatives who speak and understand french well enough to be able to read and understand the study information. * legal representatives giving written consent for their child's participation in the study. specific: case group: * trisomy 21 patient with gingival inflammation (subgroup 1) * trisomy 21 patient with healthy gingiva on intact periodontium with no history of periodontitis (subgroup 2) control group: child meeting one of these criteria: * patient with psychomotor retardation with no known repercussions on the orofacial sphere or immunity, presenting gingival inflammation (subgroup 1) * patients with psychomotor retardation and no known repercussions on orofacial health or immunity, presenting gingival health on intact periodontium with no history of gingival inflammation (subgroup 2). * patients with no known general pathology and gingival inflammation (subgroup 3) * patients with no known general pathology and healthy gingiva on intact periodontium with no history of gingival inflammation (subgroup 4) exclusion criteria: common to all groups: * patient having received antibiotic prophylaxis, antibiotic therapy or anti-inflammatory treatment in the 3 months prior to inclusion * patient included in another interventional research protocol or in a period of exclusion. * patient on ame * patients with a contraindication to the use of meopa: * patients requiring pure oxygen ventilation * intracranial hypertension * unevaluated head trauma * new-onset, unexplained neurological abnormalities * pneumothorax * emphysema bubbles * gas embolism * diving accident * abdominal gas distension, occlusion * patient recently treated with ophthalmic gas (sf6, c3f8, c2f6) * known, unsubstituted vitamin b12 deficiency specific to trisomy 21 group: - patient with no genetic diagnosis

Keywords: down syndrome trisomy 21 psychomotor retardation gingivitis periodontitis neutrophils biological collection