Identification of Clinical, Genetic and Immunological Factors Involved in the Development of Severe Bacterial Infections in Pediatrics (IBSoFACTo)

IBSoFACTo : Identification of Clinical, Genetic and Immunological Factors Involved in the Development of Severe Bacterial Infections in Pediatrics

Severe bacterial infections (SBI) are responsible for significant morbidity and mortality in the paediatric population. There is considerable individual variability in children's susceptibility to developing SBIs. This variability is multifactorial, and the mechanisms at work are not yet fully understood. The investigators of this study therefore propose to study a population of children who had particularly severe bacterial infections requiring hospitalization in a pediatric intensive care unit in France between 2015 and 2018. This study is part of a global approach to understanding the mechanisms favoring the occurrence of IBS in pediatrics.

The study will initially focus on analyzing the clinical phenotype of these children in terms of the type of infection presented, as well as immunologically with an immune workup of all these patients. The investigators also plan to contact each family individually to identify other episodes of personal or family IBS or other elements suggestive of immune deficiency (opportunistic infections, autoimmune manifestations, severe atopy). The investigators will also assess the persistent sequelae since their infectious episode, and their quality of life following this IBS.

In parallel, the genetic analysis of these patients and their parents will be carried out using whole-exome sequencing. The investigators will compare the results with those obtained in 2 IBS-free control populations (N=70 and N=116). The goal is to identify genetic variants that favor the occurrence of IBS in general, and some that are specific to certain bacteria or clinical presentations.

Study Overview

• Status: Recruiting
• Conditions: Severe Bacterial Infections
• Intervention / Treatment: Other: Extended phenotyping; Other: Blood sample for WES; Other: Blood sample for PBMC freezing; Other: POPC score evaluation; Other: Questionnaire completion

• Study Type: Interventional
• Enrollment (Estimated): 1401
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Elise LAUNAY; Phone Number: +33 2 40 08 31 79; Email: elise.launay@chu-nantes.fr
• Study Contact Backup: Name: Sponsor department; Email: bp-prom-regl@chu-nantes.fr

Study Locations

• France
  • Brest, France
    • Not yet recruiting
    • CHU de Brest
    • Contact: Jean-Michel ROUÉ, MD; Phone Number: 02 98 22 32 53; Email: jean-michel.roue@chu-brest.fr
    • Principal Investigator: Jean-Michel ROUÉ, MD
  • Lyon, France
    • Not yet recruiting
    • Hospices Civils de Lyon
    • Principal Investigator: Etienne JAVOUHEY, MD
    • Contact: Etienne JAVOUHEY, MD; Phone Number: 04 72 12 97 36; Email: etienne.javouhey@chu-lyon.fr
  • Paris, France
    • Not yet recruiting
    • Hôpital Armand Trousseau
    • Contact: Sandrine JEAN, MD; Phone Number: 01 44 73 60 65; Email: sandrine.jean@aphp.fr
    • Principal Investigator: Sandrine JEAN, MD
  • Paris, France
    • Not yet recruiting
    • Hopital Necker Enfants Malades
    • Contact: Julie TOUBIANA, MD; Phone Number: 01 44 49 40 00; Email: julie.toubiana@aphp.fr
    • Principal Investigator: Julie TOUBIANA, MD
  • Saint-Etienne, France
    • Not yet recruiting
    • Chu de Saint-Etienne
    • Contact: Hugues PATURAL, MD; Phone Number: 04 77 82 81 17; Email: hugues.patural@univ-st-etienne.fr
    • Principal Investigator: Hugues PATURAL, MD
  • Loire Atlantique
    • Nantes, Loire Atlantique, France, 44093
      • Recruiting
      • Nantes University Hospital
      • Contact: Élise LAUNAY; Phone Number: +33 2 98 22 32 53; Email: elise.launay@chu-nantes.fr
      • Principal Investigator: Elide LAUNAY

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

Study Population

We plan to include a maximum of 467 children previously included in the DIABACT IV study (NCT02167802), who were hospitalized in the Pediatric Intensive Care Unit in France for severe bacterial infection, as well as both their parents. All patients were initially included as minors. As part of the IBSoFACTo study, we plan to study their exome and that of their 2 biological parents. The results are theoretically generalizable to European children developing IBS.

Description

Inclusion Criteria:

For patients:

• Patient included in the DIABACT IV study between 2015 and 2018, following hospitalization in a pediatric intensive care unit in France for a severe bacterial infection.
• Patient affiliated to a social security system
• Patient alive at the time of inclusion.
• Written consent from legal representatives for participation in research. If one of the legal representatives is unable to complete/sign the written consent, it will be sought orally by telephone and recorded in the patient's file. If the patient is over 18, written consent will be obtained. If the patient is a minor, consent will be sought with communication adapted to his/her level of understanding and age.

For parents:

• Patient's biological parents
• Written consent

Exclusion Criteria:

• Persons under court protection
• Refusal to participate in research

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Patients with severe childhood bacterial infections; Patient inclus dans l'étude DIABACT IV (NCT02167802) entre 2015 et 2018, dans les suites de son hospitalisation en réanimation pédiatrique en France pour une infection bactérienne sévère.	Other: Extended phenotyping; Extended phenotyping (analysis performed at Nantes University Hospital, MANDATORY DELIVERY WITHIN 24 HOURS) = 1 EDTA 3 mL tube for patients included in Nantes.; Other: Blood sample for WES; Blood sample for WES : 1 x 3 mL EDTA tube (if not included in DIABACT IV biocollection); Other: Blood sample for PBMC freezing; Blood sample for PBMC freezing integrated into the biocollection: 1 EDTA tube = 3 mL; Other: POPC score evaluation; Assessment of POPC score (Pediatric Overall Performance Category); Other: Questionnaire completion; Questionnaires completed by parents or children: SDQ; PedSQL4.0
Other: Patient's biological parents	Other: Blood sample for WES; Blood sample for WES : 1 x 3 mL EDTA tube (if not included in DIABACT IV biocollection); Other: Questionnaire completion; Questionnaires completed by parents or children: SDQ; PedSQL4.0

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Identification of innate errors of immunity involved in the development of IBS in pediatrics.	List of rare genetic variants significantly more frequently found in cases than in controls and/or absent in healthy parents.	At the enrollment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Identification of inborn errors of immunity involved in the development of IBS and their association with abnormalities of the immune balance,		At the enrollment
Identification of rare genetic variants favoring certain clinical types of infection, or certain biological and immunological abnormalities.		At the enrollment
Identification of immune deficiencies in patients who have developed a severe bacterial infection		At the enrollment
Assessment of sequelae with the POPC sequelae score (Pediatric Overall Performance Category) at a distance from the IBS episode.	The POPC sequelae score is a scale from 1 to 6, with 6 being the worst possible outcome.	At the enrollment
Assessment of sequelae at a distance from the IBS episode with the Strengths and Weaknesses Questionnaire (SDQ-Fra).	The SDQ-Fra score is a scale from 0 to 2, with 2 being the worst possible outcome.	At the enrollment
Assessment of quality of life at a distance from the IBS episode.	Quality of life will be assessed in this patient population using the Pediatric Quality of Life InventoryTM (scale from 0 to 4, with 4 corresponding to the worst outcome).	At the enrollment

Collaborators and Investigators

• Sponsor: Nantes University Hospital
• Collaborators: Center for Research in Transplantation and Translational Immunology (UMR_S 1064)

Study record dates

Study Major Dates

• Study Start (Actual): March 18, 2026
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): June 1, 2029

Study Registration Dates

• First Submitted: July 17, 2025
• First Submitted That Met QC Criteria: August 5, 2025
• First Posted (Actual): August 8, 2025

Study Record Updates

• Last Update Posted (Actual): April 3, 2026
• Last Update Submitted That Met QC Criteria: March 30, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: pediatrics; Whole-exome sequencing; Inborn errors of immunity; Severe bacterial infections
• Additional Relevant MeSH Terms: Infections; Bacterial Infections and Mycoses; Bacterial Infections; Investigative Techniques; Specimen Handling; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Punctures; Surgical Procedures, Operative; Blood Specimen Collection
• Other Study ID Numbers: RC25_0061; 2025-A01367-42 (Other Identifier: ANSM - IDRCB)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No