Kidney Graft Tolerance KTOL

Non-interventional Single-center Study of the Contribution of DP8α Regulatory T Cells Induced by a Gut Microbiota Bacterium to Kidney Transplant Tolerance.

Status

Recruiting

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT06271343

Acronym

KTOL

Enrollment

Registered

2024-02-21

Start date

2024-05-14

Completion date

2027-08-22

Last updated

2026-05-05

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Kidney Transplant Tolerance

Keywords

DP8 Regulatory Lymphocytes, Intestinal Microbiota, Tolerance, Transplant, Kidney

Brief summary

Prospective experimental study using PBMC from a limited number of adult patients (15) treated at Nantes University Hospital for a kidney transplant from a related living donor. The study will be carried out on PBMC from both donors and recipients, collected during visits scheduled as part of the clinical management of the donor/recipient pair. The study will test the hypothesis that DP8α Tregs expressing CD73, whose frequency in blood increases stably after non-rejected kidney transplants, but not when patients have undergone or will subsequently undergo rejection, are enriched in donor-specific cells, which would be a strong argument in favor of a direct role for these Tregs in preventing transplant rejection, through their ability to inhibit immune responses directed against donor alloantigens.

Interventions

None listed

Study design

Observational model

CASE_CONTROL

Time perspective

PROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Inclusion criteria

* Adult donor-recipient pair. * First or second kidney transplant from a related ABO-compatible living donor. * BMI \< 35 for recipients. * Adult patients. * Patients weighing over 50 kgs.

Exclusion criteria

* Donor/recipient ABO incompatibility * BMI \> 35 for recipients

Design outcomes

Primary

Measure	Time frame	Description
To test the role of donor-specific DP8α Tregs in preventing kidney transplant rejection.	3 months	Measurement at D0 and 3 months post-transplant, and comparison, of the frequency of DP8a Tregs expressing CD73 among circulating T lymphocytes and the frequency of donor-reactive DP8a Tregs (identified in culture by their proliferative response to donor monocytes and clonal validation of DP8a Treg anti-donor reactivity at the 3-month post-transplant stage.

Secondary

Measure	Time frame	Description
Determine whether the increased anti-donor reactivity of the patient's DP8α Tregs after transplantation results from the amplification among them of clones and establish, if possible, the anti-donor reactivity of amplified clones.	3 months	Sorting of DP8a Tregs from the patient's blood before transplantation (D0) and at 3 months post-transplant, comparison of the TCR repertoire (TRA and TRB) of Tregs between these two stages, by a service provider. Identification (if possible by their Vb) of donor-reactive clones among the amplified TCR clones.
Determine whether clones of DP8α Tregs (reactive or not to donor antigens) are reactive to F. prausnitzii bacteria.	3 months	The response (proliferation or cytokine secretion) of donor-reactive DP8α Tregs clones will be tested against patient monocytes loaded with F. prausnitzii bacteria.

Countries

France

Contacts

CONTACTChristophe MASSET, PH

christophe.masset@chu-nantes.fr33 2 76 64 39 61

Outcome results