Study of the Serotype and Genotype of BK Virus in Kidney Transplant Recipients and Their Donors to Identify Individuals at Risk of Nephropathy
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 发起方
- 入组人数
- 100
- 试验地点
- 1
- 主要终点
- To describe the prevalence and variability of different BKPyV genotypes and serotypes in a population of kidney transplant patients with BKPyV viruria/viremia.
研究概览
简要总结
The aim of this observational study is to characterize the urinary replication of BK polyomavirus (BKV) in kidney transplant recipients. Although BKV reactivation after transplantation is well established, the origin of the replicating virus remains uncertain. Current evidence suggests that BKV detected in recipients may originate either from the transplanted kidney (donor-derived) or from viral reactivation in the recipient. The evaluation of new biomarkers to predict BKV replication are needed.
This study seeks to address the following key questions:
- Origin of the replicating virus: Is the BKV detected in the recipient identical to the virus originating from the donor kidney?
- Host immune response and viral genotype: Is there an association between the recipient's immune response and the genotype of the replicating BKV?
- Differences in immune response according to viral replication profile: Does the immune response differ between patients presenting isolated BKV viruria and those with both viruria and viremia?
- Can new biomarkers help predict BKV replication and viremia?
Patients will be grouped according to their BKV replication profile:
Group 1: patients with BKV viruria without viremia Group 2: patients with both BKV viruria and viremia Comparisons between these two groups will help identify whether different viral genotypes or immune responses are associated with systemic dissemination (viremia).
Kidney transplant recipients will be included if they present BKV viruria during their post-transplant follow-up. Additional blood samples will be collected during scheduled follow-up visits at the university hospital. These visits are part of routine clinical care, and no extra visits will be required specifically for the study.
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Prospective
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Kidney transplant patients with a first positive BK virus viral load in urine. - BK virus viral load in urine > 3 log copies/mL.
- •More than 3 months post-transplant and less than 2 years post-transplant.
- •Men or women aged 18 years and older.
- •Followed up at Grenoble Alpes University Hospital.
- •Affiliated with social security or beneficiary of such a scheme.
- •Patients who are not opposed to the TYPIK study.
排除标准
- •Expected renal graft survival is < 6 months, estimated by an eGFR < 15 mL/min/1.73 m² at the time of BKPyV viruria
- •Patients who object to the use of their data and/or samples for research purposes
- •Subjects who are excluded from another study
- •Subjects under administrative or judicial supervision
结局指标
主要结局
To describe the prevalence and variability of different BKPyV genotypes and serotypes in a population of kidney transplant patients with BKPyV viruria/viremia.
时间窗: up to 2 years
The primary endpoint will be the classification by genotyping/serotyping of BKPyV obtained during the first viruria and the first viremia, performed using NGS and serotyping using a seroneutralization technique. The search for SNPs (single nucleotide polymorphisms) will also enable the subclassification of genotypes and better identification of patients at risk of BKPyV viremia and therefore BKPyV-induced nephropathy.
次要结局
- Compare the viral genotype at the first viruria/viremia with the donor serotype and with the recipient serotype.(up to 2 years)
- Describe the evolution of urinary BKPyV viral load during infection and compare viruria between viruric-only and viremic patients.(up to 2 years)
- Describe associations between urinary and blood BKPyV viral load and associated genotypes/the presence of a mismatch between the donor serotype and the recipient genotype.(up to 2 years)
- Describe the associations between the waiting time until the first viremia and the presence or absence of a serotype mismatch at the time of transplantation, the genotype at the time of the first viruria, the viral load at the time of the first viruria,(up to 2 years)
- Compare the evolution of the anti-BKPyV T-cell functional response in patients with viruria alone and those also with viremia between inclusion and 6 months later.(up to 2 years)
- Describe the link between the functional response and the presence of viremia, the evolution of the BKPyV viral load in the blood, and the genotype.(up to 2 years)
- Compare the BKPyV genotype present in the renal biopsy at M3 with the urinary replicative genotype at inclusion and the donor serotype.(up to 2 years)
- Quantitatively describe the presence of BKPyV microRNAs in urine and compare the two groups (viremic and viruric alone).(up to two years)
- Describe the link between the quantity of BKPyV microRNAs and the replicative genotype.(up to 2 years)
- Quantitatively describe the presence of urinary chemokines and compare the two groups (viremic and viruric alone).(up to 2 years)
- Describe the link between the quantity of B-KPyV chemokines at inclusion and the replicative genotype.(up to 2 years)
- Monitor the number of BKV viruria or viremia depending on the immunosuppressive treatment received.(up to 2 years)
- Comparison of number of positive ELISpot in group with and without viremia (identify risk factor of viremia)(up to 2 years)
- Comparison of SV40 immunohistochemistry staining results and BKPyV PCR results on M3 biopsy(up to 2 years)