Antibody Mediated Rejection After Kidney TransplantationB-KiMiNCT07134491
Peripheral and Intrarenal B Cell Study in Antibody Mediated Transplant Rejection : Phenotypic and Transcriptional Study, Study of Reactivity
An observational study of Antibody Mediated Rejection After Kidney Transplantation, run by Assistance Publique - Hôpitaux de Paris at 2 sites in France.
Trial summary
Humoral rejection of kidney transplants is responsible for a large number of kidney graft losses in a context of increasing shortage. Although it has been established that it is largely mediated by the alloreactive B lymphocyte, anti-B therapies are only partially effective. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Antibody Mediated Rejection After Kidney Transplantation
- What is being tested?
- Piece of kidney removal, Stool collection and Blood collection
- How many people
- 45 participants
- Where
- 2 sitesFrance
- Study dates
- 13 Mar 2026to 13 Mar 2029
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: This study covers a population of adult kidney transplant patients admitted for biopsy or graft removal in the participating nephrology departments.
Who may be able to join
- 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
Who cannot join
- Confounding factor of renal inflammation: acute or recurrent pyelonephritis, BK virus nephropathy
- Pregnant or breast-feeding women
- Persons under legal protection
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
France2 sites, 2 recruiting
- Recruiting
Nephrology department, Hôpital Pitié Salpêtière
Paris, 75013
Yanis TAMZALI, MD, MsC, 01 84 82 82 21 ext. +33, yanis.tamzali@aphp.fr
- Not yet recruiting
Nephrology department, Tenon hospital
Paris, 75020
Emmanuel ESTEVE, 01 56 01 54 49 ext. +33, emmanuel.esteve@aphp.fr
About this study
Humoral rejection of kidney transplants is responsible for a large number of kidney graft losses in a context of increasing shortage.
Although it has been established that it is largely mediated by the alloreactive B lymphocyte, anti-B therapies are only partially effective.
Read more
The mechanisms behind the loss of tolerance are also poorly understood, and the triggers of rejection remain to be elucidated.
During this study, patients admitted for kidney graft biopsy for suspicion of rejection will be included ; patients presenting non inflammatory biopsies will be studied as controls. B cells will be extracted and cultured. Their antibodies will be studied along with reactivity towards HLA, non HLA targets and the gut microbiome. The same study will be led for late rejections needing graft removal : B cells extraction, culture, antibodies reactivity testing. Controls will be graft removal for non inflammatory causes. In both cases hight throughput sequencing the immunoglobulin genes will be performed.
- Being tested
- Piece of kidney removal, Stool collection, Blood collection
- Keywords
- Kidney transplantation, Rejection, Donor-specific antibodies, Human Leukocyte Antigen, Microbiome
- Medical subject headings
- Rejection, Psychology
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Piece of kidney removalBiological
removal for a piece of kidney for research purposes during biopsy or graft removal performed as part of routine care
Stool collectionBiological
Stool collection for research purposes
Blood collectionBiological
Additional blood volume for research purposes during a routine blood collection
| Study group | Role | What they receive |
|---|---|---|
| kidney biopsy or graft removal for rejection | Renal transplant recipients with suspicion of rejection or undergoing kidney biopsy or graft removal Receives: Biological: Piece of kidney removal; Biological: Stool collection; Biological: Blood collection | |
| kidney biopsy or graft removal for reasons other than rejection | Renal transplant recipients with undergoing kidney graft removal or biopsy for reansons other than rejection Receives: Biological: Piece of kidney removal; Biological: Stool collection; Biological: Blood collection |
What is being measured
The primary outcome is the main question the study is designed to answer.
Characterization of lymphocytes in humoral rejection
Using Flow cytometry analysis
Measured: Day 1
Secondary outcomes (1)
Analyze of gut microbiota of kidney transplant patients
Using Flow cytometry analysis
Measured: Day 1
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Aug 2025
- Study start13 Mar 2026
- Primary completion13 Mar 2029 (estimated)
- Study completion13 Mar 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Antibody Mediated Rejection After Kidney TransplantationStudies of the same condition, open and under way.
- More trials run by Assistance Publique - Hôpitaux de ParisThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case-control
- Time perspective
- Prospective
- Enrolment
- 45 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Assistance Publique - Hôpitaux de Paris
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07134491
- Sponsor's protocol ID
- APHP250908
- Acronym
- B-KiMi
- Status last verified
- Mar 2026
- First submitted
- 8 Jul 2025
- Last updated
- 18 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: The procedures carried out with the French data privacy authority (CNIL, Commission nationale de l'informatique et des libertés) do not provide for the transmission of the database, nor do the information and consent documents signed by the patients. Consultation by the editorial board or interested researchers of individual participant data that underlie the results reported in the article after deidentification may nevertheless be considered, subject to prior determination of the terms and conditions of such consultation and in respect for compliance with the applicable regulations.
Study at a glance
From the registry record, last updated by the sponsor on 18 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Peripheral and Intrarenal B Cell Study in Antibody Mediated Transplant Rejection : Phenotypic and Transcriptional Study, Study of Reactivity
- ClinicalTrials.gov ID
- NCT07134491
- Acronym / sponsor ID
- B-KiMi / APHP250908
- Keywords
- Kidney transplantation, Rejection, Donor-specific antibodies, Human Leukocyte Antigen, Microbiome
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 45 participants (estimated)
- Lead sponsor
- Assistance Publique - Hôpitaux de ParisUniversity, hospital or other
- Study start
- 13 Mar 2026 (actual)
- Primary completion
- 13 Mar 2029 (estimated)
- Study completion
- 13 Mar 2029 (estimated)
- First posted
- 21 Aug 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Humoral rejection of kidney transplants is responsible for a large number of kidney graft losses in a context of increasing shortage.
Although it has been established that it is largely mediated by the alloreactive B lymphocyte, anti-B therapies are only partially effective.
The mechanisms behind the loss of tolerance are also poorly understood, and the triggers of rejection remain to be elucidated.
During this study, patients admitted for kidney graft biopsy for suspicion of rejection will be included ; patients presenting non inflammatory biopsies will be studied as controls. B cells will be extracted and cultured. Their antibodies will be studied along with reactivity towards HLA, non HLA targets and the gut microbiome. The same study will be led for late rejections needing graft removal : B cells extraction, culture, antibodies reactivity testing. Controls will be graft removal for non inflammatory causes. In both cases hight throughput sequencing the immunoglobulin genes will be performed.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| kidney biopsy or graft removal for rejection | – | Biological: Piece of kidney removal, Biological: Stool collection, Biological: Blood collectionRenal transplant recipients with suspicion of rejection or undergoing kidney biopsy or graft removal |
| kidney biopsy or graft removal for reasons other than rejection | – | Biological: Piece of kidney removal, Biological: Stool collection, Biological: Blood collectionRenal transplant recipients with undergoing kidney graft removal or biopsy for reansons other than rejection |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- This study covers a population of adult kidney transplant patients admitted for biopsy or graft removal in the participating nephrology departments.
Key inclusion criteria (3 listed)
- 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
Key exclusion criteria (3 listed)
- Confounding factor of renal inflammation: acute or recurrent pyelonephritis, BK virus nephropathy
- Pregnant or breast-feeding women
- Persons under legal protection
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Piece of kidney removalremoval for a piece of kidney for research purposes during biopsy or graft removal performed as part of routine care | Biological | kidney biopsy or graft removal for reasons other than rejection, kidney biopsy or graft removal for rejection |
| Stool collectionStool collection for research purposes | Biological | kidney biopsy or graft removal for reasons other than rejection, kidney biopsy or graft removal for rejection |
| Blood collectionAdditional blood volume for research purposes during a routine blood collection | Biological | kidney biopsy or graft removal for reasons other than rejection, kidney biopsy or graft removal for rejection |
Primary outcome
Characterization of lymphocytes in humoral rejection
Time frame: Day 1
Using Flow cytometry analysis
1 secondary outcome
Analyze of gut microbiota of kidney transplant patients
Time frame: Day 1
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Mar 2026.
- Individual participant dataSharing planned: Yes. The procedures carried out with the French data privacy authority (CNIL, Commission nationale de l'informatique et des libertés) do not provide for the transmission of the database, nor do the information and consent documents signed by the patients. Consultation by the editorial board or interested researchers of individual participant data that underlie the results reported in the article after deidentification may nevertheless be considered, subject to prior determination of the terms and conditions of such consultation and in respect for compliance with the applicable regulations.
Related trials for Antibody Mediated Rejection After Kidney Transplantation
RecruitingPhase 4
Safety and Efficacy of the Bispecific T-Cell Engager (BiTE) in Kidney Transplant Recipients With Chronic Active Antibody-Mediated Rejection
Antibody Mediated Rejection After Kidney Transplantation
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Antibody Mediated Rejection After Kidney Transplantation, run by Assistance Publique - Hôpitaux de Paris at 2 sites in France.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 18 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in France. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Yanis TAMZALI, MD, MsC (681402564 ext. +33, yanis.tamzali@aphp.fr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Characterization of lymphocytes in humoral rejection (time frame: Day 1). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Mar 2026; AzTrials last refreshed its copy on 6 Nov 2026.