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

Study Overview
=================
Brief 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.

Detailed Description
-----------------
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.

Official Title
-----------------
Study of Neutrophils During Gingival Inflammation in Children With Down Syndrome/Trisomy 21

Conditions
-----------------
Periodontitis, Trisomy 21

Intervention / Treatment
-----------------
* Procedure: Biological sampling


Participation Criteria
=================
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

Ages Eligible for Study
-----------------
Minimum Age: 3 Years
Maximum Age: 12 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Child patient consulting the service<br>Trisomy 21 patient with gingival inflammation (subgroup 1) Trisomy 21 patient with healthy gingiva on intact periodontium with no history of periodontitis (subgroup 2) 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) | Procedure: Biological sampling<br>* - Saliva and blood sampling<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Distinction of neutrophil subtypes according to co-expression of markers of neutrophil function among a panel of 24 markers by flow cytometry | purification od neutrophils from blood and saliva Fixation Cell sorting using FACS on a panel of 24 markers | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluation of neutrophil subtypes present in saliva and study of a correlation with blood neutrophils during periodontal health and periodontal inflammation (intra individual analysis) | Correlation with previous results | 1 year | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Down syndrome, Trisomy 21, psychomotor retardation, gingivitis, periodontitis, neutrophils, biological collection