B cells in antibody-mediated kidney transplant rejection: their characteristics and what they react to.

Peripheral and Intrarenal B Cell Study in Antibody Mediated Transplant Rejection : Phenotypic and Transcriptional Study, Study of Reactivity

Observational Assistance Publique - Hôpitaux de Paris · NCT07134491

This project will test whether B cells taken from kidney transplant patients with suspected antibody-mediated rejection produce antibodies that react to donor HLA, other targets, or gut microbes.

Quick facts

Study typeObservational
Enrollment45 (estimated)
Ages18 Years and up
SexAll
SponsorAssistance Publique - Hôpitaux de Paris Academic / other
Locations2 sites (Paris and 1 other locations)
Trial IDNCT07134491 on ClinicalTrials.gov

What this trial studies

Adult kidney transplant recipients who undergo a biopsy for suspected rejection or surgical graft removal will be enrolled alongside control patients with non-inflammatory findings. Investigators will extract and culture B cells from blood and kidney tissue, collect stool and blood samples, and test the antibodies those B cells produce for reactivity to HLA, non-HLA targets, and components of the gut microbiome. High-throughput sequencing of immunoglobulin genes will be used to characterize B-cell repertoires in both peripheral blood and intrarenal compartments. The study is observational and aims to link B-cell phenotypes and antibody specificities with clinical rejection events.

Who should consider this trial

Good fit: Adult kidney transplant recipients admitted for biopsy or graft removal who can provide informed consent and are affiliated with a health insurance system are ideal candidates.

Not a fit: Patients with confounding renal infections (acute or recurrent pyelonephritis, BK virus nephropathy), pregnant or breastfeeding women, and those under legal protection are excluded and unlikely to benefit from participation.

Why it matters

Potential benefit: If successful, the results could identify triggers and specific antibody targets that help guide more precise prevention or treatment strategies to reduce graft loss.

How similar studies have performed: Previous work has characterized B-cell roles and anti-HLA antibodies in rejection, but combining paired intrarenal and peripheral B-cell profiling with microbiome reactivity and high-throughput immunoglobulin sequencing is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Adult kidney transplant recipients admitted for biopsy or graft removal in the participating nephrology departments.
* Patient participation agreement and signed consent form
* Affiliation to a health insurance system

Exclusion Criteria:

* Confounding factor of renal inflammation: acute or recurrent pyelonephritis, BK virus nephropathy
* Pregnant or breast-feeding women
* Persons under legal protection

Where this trial is running

Paris and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Antibody Mediated Rejection After Kidney TransplantationKidney transplantationRejectionDonor-specific antibodiesHuman Leukocyte AntigenMicrobiome
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.