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Study of Anti-BKPyV Immune Responses in Kidney Transplant Patients With BKPyV Viremia

Official Title Étude Des réponses Immunes Anti-BKPyV Chez Les Patients transplantés rénaux Avec BKPyV virémie

Status
Not yet recruiting
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT06988072
Acronym
NEPHRO-BK
Enrollment
75
Registered
2025-05-23
Start date
2025-05-30
Completion date
2028-05-30
Last updated
2025-05-23

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

Conditions

BK Polyomavirus, Kidney Transplant

Keywords

Polyomavirus hominis 1, Natural killer cells, T-lymphocytes, Neutralizing antibodies, Adaptative immunity, Immunologic memory, Innate immunity recognition, Trained immunity, Immune repertoire, Biomarkers, BKPyV-association nephropathy

Brief summary

The human pathogen BK polyomavirus (BKPyV) is a ubiquitous, small, non-enveloped DNA virus that infects over 90% of people, typically in childhood with mild or no symptoms. Following primary infection, BKPyV establishes latency predominantly in the reno-urinary tract, and can occasionally be detected in the urine without any concomitant clinical symptoms. However, among kidney transplant recipients (KTR), due to impaired cellular and humoral immunity, uncontrolled viral replication in renal tubular epithelial cells (RPTE) can occur, leading to high-level BKPyV DNAemia and significant damage to the reno-urinary system (ie polyomavirus-associated nephropathy). In the absence of any effective antiviral drug, the mainstay of therapy for significant BKPyV replication among KTR is reducing immunosuppressive drugs, despite the subsequent of risk of graft rejection. Current efforts to identify new monitoring and therapeutical strategies need to be supported by a better understanding of the dynamics of BKPyV-specific immune responses following transplantation. Although adaptive cellular and humoral immune responses play a crucial role in the control of BKPyV reactivation among healthy individuals, immunosuppression and transplantation disrupt immune homeostasis and reshape the immune response landscape both in terms of function and fitness to new stimuli. Consequently, pre-transplant prediction of patients who will be able to control post-transplant BKPyV reactivation or who will develop BKPyV-related complications remains challenging. This knowledge gap stems from insufficient studies on the comprehensive analysis of immune responses during BKPyV reactivation. In particular, most studies to date have not investigated the role of NK cells in this context, despite their potent antiviral activity, heterogenous repertoire in each patient and their recently uncovered adaptive properties. The hypothesis is that among KTR with de novo BKPyV DNAemia, the comprehensive analysis of anti-BKPyV immune responses (including both the description of NK cell repertoire and adaptive immune), could allow * A better stratification of KTR at-risk for BKPyV-related complications using accessible immune biomarkers. * The identification of the most efficient strategies of immunosuppression management for the control of BKPyV DNAemia, that could be further evaluated in a prospective cohort. * The identification of immunological correlates for the control of BKPyV DNAemia, which aim at providing a foundation for the development of future immunotherapeutic strategies.

Interventions

OTHERblood sampling

At BKPyV reactivation, at 1 month, 3 months and 12 months

Sponsors

Assistance Publique - Hôpitaux de Paris
Lead SponsorOTHER

Study design

Observational model
COHORT
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
7 Years to No maximum
Healthy volunteers
Yes

Inclusion criteria

* No objection to participation in the research study (from patients or legal guardians) * Affiliated to the French national social security system * Age ≥ 7 years old * Weight ≥ 12 kg Additional criteria for kidney transplant recipients with BKPyV DNAemia: * Patients who underwent kidney transplantation within 12 months prior to inclusion, regardless of the initial indication * Detectable de novo BKPyV DNAemia within the first 12 months post-transplantation Additional criteria for kidney transplant recipients without BKPyV DNAemia: * Patients who underwent kidney transplantation within 12 months prior to inclusion, regardless of the initial indication * No detectable de novo BKPyV DNAemia within the first 12 months post-transplantation Additional criteria for healthy donors (controls): * Age ≥ 18 years old * Blood donation to the EFS * Consent for the use of their blood donation for research purposes.

Exclusion criteria

* Objection to participation in the research study

Design outcomes

Primary

MeasureTime frameDescription
Number of circulating NK cellsAt inclusionNK cells circulating repertoire defects associated with BKPyV-DNAemia Extensive characterization of the phenotype of circulating NK cells among kidney transplant recipients with de novo BKPyV DNAemia to predict the clinically relevant outcome BKPyV reactivation control

Secondary

MeasureTime frameDescription
Frequency of T- and B-cell specific functional responses in patients with de novo BKPyV reactivationUp to 12 monthsViral neutralization assays (humoral responses) and anti-BKPyV ELISPOT assays (T cell responses) At each available timepoint
Correlation between the main changes in immunosuppressive treatment and the anti-BPyV immune responseUp to 12 monthsCorrelation between the main changes in immunosuppressive treatment carried out after the appearance and BKPyV viremia and the anti-BKPyV immune response assessed by the immunological biomarkers
Correlation between the main changes in immunosuppressive treatment and the control of BKPyV viremiaUp to 12 months
Frequency of Functional Impact of BKPyV Reactivation on NK Cell Effector FunctionsUp to 12 monthsCytotoxicity assays of NK cells in response to antigenic stimulation (pre-specified BKPyV peptides) and co-culture models (BKPyV-infected RPTEC) At each available timepoint
Correlation between the main changes in immunosuppressive treatment and the occurrence of rejectionUp to 12 months
BKPyV viral diversity evolution during clinical course of infectionUp to 12 monthsWhole genome sequencing (WGS) of BKPyV on consecutive plasma sample among patients with BKPyV DNAemia (characterization of major and minor viral subpopulations, identification of coinfections) At eaxh available timetpoint
Impact of BKPyV reactivation on alloreactive properties of NK cellsUp to 12 monthsNK cells cytotoxicity assessments against allogenic endothelial cells after stimulation by BKPyV (infected cells and/or BKPyV isolated peptides)
Correlation between the main changes in immunosuppressive treatment and the occurrence of BKPyV nephropathyUp to 12 months

Contacts

Primary ContactJulien Gras, MD
julien.gras@aphp.fr+33142494991
Backup ContactJérôme Lambert, MD PhD
jerome.lambert@u-paris.fr+33142499742

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026