CHOICE KERGUELEN 2 : Consequences of Longterm Confinement on Immunity in the Sub-Antarctic Islands : Follow-up of Volunteers on the Kerguelen Islands

NCT07275489 | Recruiting

• 2 other identifiers: 49RC25_04392025-A02538-41
• Study Type: observational
• Target: 9
• Locations: 1 country
• Sites: 1

Brief Summary

Living for long periods in extreme environments-like Antarctic research stations or space missions-can have a significant impact on human health, especially on the immune system. Scientists have observed that people in such isolated conditions often experience more infections and a reactivation of viruses that usually stay dormant in the body, such as Herpes viruses. These changes affect both parts of the immune system: the rapid-response "innate" system and the slower, more specific "adaptive" system. These immune disruptions may be caused by multiple stressors: ongoing psychological stress, disturbed sleep and light cycles (circadian rhythm disruption), and the challenges of living in confined, isolated, and extreme environments. While space missions and Antarctic overwintering programs have provided some insight into these issues, scientists still lack a detailed understanding of how the immune system adapts-or fails to adapt-over time in such conditions. To help fill this gap, the CHOICE Kerguelen 2 study will follow a group of healthy young adults who will spend one year (from November 2025 to November 2026) in Port-aux-Français, a remote French research station on the Kerguelen Islands in the sub-Antarctic. These volunteers are participating in a civic service program and will be living in a highly isolated environment for the duration of their mission. The CHOICE Kerguelen study is conducted in collaboration with the French Polar Institute (IPEV). The goal of the study is to collect and store a broad range of biological samples-including blood, saliva, stool, urine, and hair-from these volunteers at four time points during the time of their confinement on the Kerguelent Islands: tevery three months during their stay. These samples will be than analyzed to characterize the immune profiles and intestinal microbiota of the subjects assess eventual viral reactivations and stress biological markers. These analyses will allow to better understand how the immune system reacts to prolonged isolation, and to identify immune profiles that may develop under prolonged stress and limited social contact. The long-term aim of this project is not only to improve our understanding of human immunity in extreme environments, but also to inform medical research for people living with chronic illness. By studying healthy individuals placed in physically and mentally challenging environments, scientists can better understand how stress and isolation may weaken immune defenses. The findings may one day help design new approaches to support immune health in vulnerable populations.

Conditions

Human Health in Extreme Conditions

Outcome Measures

Primary Outcomes (24)

• lymphocytes subsets during overwintering on the Kerguelen Islands

  lymphocytes subsets by flow cytometry

  At inclusion (3 months after the beginning of overwintering)

• lymphocytes subsets during overwintering on the Kerguelen Islands

  lymphocytes subsets by flow cytometry

  At 3 months (6 months after the beginning of overwintering )

• lymphocytes subsets during overwintering on the Kerguelen Islands

  lymphocytes subsets by flow cytometry

  At 6 months (9 months after the beginning of overwintering )

• lymphocytes subsets during overwintering on the Kerguelen Islands

  lymphocytes subsets by flow cytometry

  At 9 months (12 months after the beginning of overwintering )

• RNAsep during overwintering on the Kerguelen Islands

  RNAseq

  At inclusion (3 months after the beginning of overwintering )

• RNAsep during overwintering on the Kerguelen Islands

  RNAseq

  At 3 months (6 months after the beginning of overwintering )

• RNAsep during overwintering on the Kerguelen Islands

  RNAseq

  At 6 months (9 months after the beginning of overwintering )

• RNAsep during overwintering on the Kerguelen Islands

  RNAseq

  At 9 months (12 months after the beginning of overwintering )

• plasmatic cytokines during overwintering on the Kerguelen Islands

  plasmatic cytokines by Bioplex

  At inclusion (3 months after the beginning of overwintering )

• plasmatic cytokines during overwintering on the Kerguelen Islands

  plasmatic cytokines by Bioplex

  At 3 months (6 months after the beginning of overwintering )

• plasmatic cytokines during overwintering on the Kerguelen Islands

  plasmatic cytokines by Bioplex

  At 6 months (9 months after the beginning of overwintering )

• plasmatic cytokines during overwintering on the Kerguelen Islands

  plasmatic cytokines by Bioplex

  At 9 months (12 months after the beginning of overwintering )

• fecal microbiota

  fecal microbiota by bacterial sequencing

  At inclusion (3 months after the beginning of overwintering )

• fecal microbiota

  fecal microbiota by bacterial sequencing

  At 3 months (6 months after the beginning of overwintering )

• fecal microbiota

  fecal microbiota by bacterial sequencing

  At 6 months (9 months after the beginning of overwintering )

• fecal microbiota

  fecal microbiota by bacterial sequencing

  At 9 months (12 months after the beginning of overwintering )

• hormonal stress markers during overwintering on the Kerguelen Islands

  hormonal stress markers assessment in blood/urinary/hair by Elisa and nephelemetry

  At inclusion (3 months after the beginning of overwintering )

• hormonal stress markers during overwintering on the Kerguelen Islands

  hormonal stress markers assessment in blood/urinary/hair by Elisa and nephelemetry

  At 3 months (6 months after the beginning of overwintering )

• hormonal stress markers during overwintering on the Kerguelen Islands

  hormonal stress markers assessment in blood/urinary/hair by Elisa and nephelemetry

  At 6 months (9 months after the beginning of overwintering )

• hormonal stress markers during overwintering on the Kerguelen Islands

  hormonal stress markers assessment in blood/urinary/hair by Elisa and nephelemetry

  At 9 months (12 months after the beginning of overwintering )

• stress profile during overwintering on the Kerguelen Islands

  psychological stress by CST test form

  At inclusion (3 months after the beginning of overwintering )

• stress profile during overwintering on the Kerguelen Islands

  psychological stress by CST test form

  At 3 months (6 months after the beginning of overwintering )

• stress profile during overwintering on the Kerguelen Islands

  psychological stress by CST test form

  At 6 months (9 months after the beginning of overwintering )

• stress profile during overwintering on the Kerguelen Islands

  psychological stress by CST test form

  At 9 months (12 months after the beginning of overwintering )

Secondary Outcomes (16)

• EBV viral reactivations during overwintering on the Kerguelen Islands

  At inclusion (3 months after the beginning of overwintering )

• EBV viral reactivations during overwintering on the Kerguelen Islands

  At 3 months (6 months after the beginning of overwintering )

• EBV viral reactivations during overwintering on the Kerguelen Islands

  At 6 months (9 months after the beginning of overwintering )

• EBV viral reactivations during overwintering on the Kerguelen Islands

  At 9 months (12 months after the beginning of overwintering )

• CMV viral reactivations during overwintering on the Kerguelen Islands

  At inclusion (3 months after the beginning of overwintering )

Study Arms (1)

HD (healthy donors)

Other: blood ponction; Other: urines collection; Other: hair collection; Other: saliva collection; Other: stools collection

Interventions

blood ponction OTHER

blood ponction

HD (healthy donors)

urines collection OTHER

urines collection

HD (healthy donors)

hair collection OTHER

hair collection

HD (healthy donors)

saliva collection OTHER

saliva collection

HD (healthy donors)

stools collection OTHER

stools collection

HD (healthy donors)

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Participant included in the CELREMED research project of the University Hospital of Angers on helathy volunteers in the context of CHOICE Kerguelen 1 protocol

You may qualify if:

• healthy people aged \> 18 years
• Participant affiliated with or benefiting from a social security system
• Participant has signed informed consent
• Participant staying as an overwintering member at Kerguelen from November 2025 to November 2026
• Participant included in the CELREMED research project of the University Hospital of Angers on helathy volunteers in the context of CHOICE Kerguelen 1 protocol

You may not qualify if:

• age \< 18 years
• Pregnant, breastfeeding, or postpartum woman
• immunocompromised people (primary immunodeficiency, HIV infection or immunosupressive treatment)
• Person refusing to participate in the study
• Person with a history of autoimmune disease - -Person deprived of liberty by judicial or administrative decision
• Person undergoing involuntary psychiatric treatment
• Person subject to a legal protection measure

Sponsors & Collaborators

• University Hospital, Angers: lead
• Institut Polaire Français Paul Emile Victor: collaborator

Study Sites (1)

Hôpital SAMUKER, Port-aux-français/ Archipel KERGUELEN /Terres Australes et Antarctiques Françaises

Port-aux-Français, Terres Australes Et Antarctiques Françaises, French Southern and Antarctic Lands

RECRUITING

Biospecimen

Retention: SAMPLES WITH DNA

whole blood, PBMCs, plasma, serum, urine, saliva, stools, hair

Study Officials

• Charline MIOT, MD

  University Hospital, Angers

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Charline MIOT, MD

CONTACT

02 41 35 36 37; chmiot@chu-angers.fr

Anthéa LOIEZ

CONTACT

02 41 35 36 37; DRCI-Promotion-Interne@chu-angers.fr

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER GOV
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 27, 2025
• First Posted: December 10, 2025
• Study Start: December 20, 2025
• Primary Completion: January 31, 2026
• Study Completion (Estimated): December 31, 2026
• Last Updated: December 30, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL
• Time Frame: The data will be shared after signing a negotiated data transfer agreement ( data access agreement), for the duration specified in the agreement.
• Access Criteria: The data will be made available via secure transfer (sharing platform approved by the university hospital: BlueFiles or Oodrive).

Locations

FR (1)