An observational study in BK Polyomavirus and Kidney Transplant, sponsored by Assistance Publique - Hôpitaux de Paris. Not yet recruiting. Open to participants aged 7 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-05-23.
Sponsored by Assistance Publique - Hôpitaux de Paris · Observational
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
Assistance Publique - Hôpitaux de Paris is the lead sponsor of 3,505 studies on the registry; 1,006 are open to participants now.
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Study population: kidney transplant recipients with de novo BKPyV DNAemia within the first 12 months post-transplantation, including adult and pediatric patients.
Control subjects: control subjects will be matched to the study patients (criteria below with a ratio of 1-1-1):
Additional criteria for kidney transplant recipients with BKPyV DNAemia:
Additional criteria for kidney transplant recipients without BKPyV DNAemia:
Additional criteria for healthy donors (controls):
Exclusion Criteria:
kidney transplant recipients with de novo BKPyV DNAemia within the first 12 months post-transplantation, including adult and pediatric patients
Other: blood sampling
Other: blood sampling
Other: blood sampling
At BKPyV reactivation, at 1 month, 3 months and 12 months
once
once
Number of circulating NK cells
NK 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"
Time frame: At inclusion
Number of circulating NK cells
NK 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"
Time frame: At 1 month
Number of circulating NK cells
NK 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"
Time frame: At 3 months
Number of circulating NK cells
NK 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"
Time frame: At 12 months
Frequency of Functional Impact of BKPyV Reactivation on NK Cell Effector Functions
Cytotoxicity assays of NK cells in response to antigenic stimulation (pre-specified BKPyV peptides) and co-culture models (BKPyV-infected RPTEC) At each available timepoint
Time frame: Up to 12 months
Frequency of T- and B-cell specific functional responses in patients with de novo BKPyV reactivation
Viral neutralization assays (humoral responses) and anti-BKPyV ELISPOT assays (T cell responses) At each available timepoint
Time frame: Up to 12 months
Correlation between the main changes in immunosuppressive treatment and the anti-BPyV immune response
Correlation 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
Time frame: Up to 12 months
Correlation between the main changes in immunosuppressive treatment and the control of BKPyV viremia
Time frame: Up to 12 months
Correlation between the main changes in immunosuppressive treatment and the occurrence of BKPyV nephropathy
Time frame: Up to 12 months
Correlation between the main changes in immunosuppressive treatment and the occurrence of rejection
Time frame: Up to 12 months
BKPyV viral diversity evolution during clinical course of infection
Whole 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
Time frame: Up to 12 months
Impact of BKPyV reactivation on alloreactive properties of NK cells
NK cells cytotoxicity assessments against allogenic endothelial cells after stimulation by BKPyV (infected cells and/or BKPyV isolated peptides)
Time frame: Up to 12 months
No study locations are listed for this record.
Plan to share: Undecided
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Assistance Publique - Hôpitaux de Paris