Detection of donor-derived cell-free DNA in the setting of multiple kidney transplantations
Linnea Pettersson1, Lukas Frischknecht2, Sofia Westerling1
1Devyser AB, Stockholm, Sweden.
Background:
The routine use of donor-derived cell-free DNA (dd-cfDNA) assays to monitor graft damage in patients after kidney transplantation is being implemented in many transplant centers worldwide. The interpretation of the results can be complicated in the setting of multiple sequential kidney transplantations where accurate donor assignment of the detected dd-cfDNA can be methodologically challenging.
Methods:
We investigated the ability of a new next-generation sequencing (NGS)-based dd-cfDNA assay to accurately identify the source of the detected dd-cfDNA in artificially generated samples as well as clinical samples from 31 patients who had undergone two sequential kidney transplantations.
Results:
The assay showed a high accuracy in quantifying and correctly assigning dd-cfDNA in our artificially generated chimeric sample experiments over a clinically meaningful quantitative range. In our clinical samples, we were able to detect dd-cfDNA from the first transplanted (nonfunctioning) graft in 20% of the analyzed patients. The amount of dd-cfDNA detected from the first graft was consistently in the range of 0.1%-0.6% and showed a fluctuation over time in patients where we analyzed sequential samples.
Conclusion:
This is the first report on the use of a dd-cfDNA assay to detect dd-cfDNA from multiple kidney transplants. Our data show that a clinically relevant fraction of the transplanted patients have detectable dd-cfDNA from the first donor graft and that the amount of detected dd-cfDNA is in a range where it could influence clinical decision-making.
Insights
Donor-derived cell-free DNA (dd-cfDNA) assays can detect signals from previous kidney transplants. This new NGS assay accurately identifies dd-cfDNA sources, aiding clinical decisions in multi-transplant patients.
Area of Science:
- Nephrology
- Transplant Immunology
- Molecular Diagnostics
Background:
- Donor-derived cell-free DNA (dd-cfDNA) assays are increasingly used to monitor kidney transplant health.
- Interpreting dd-cfDNA results becomes complex in patients with multiple sequential kidney transplants.
- Accurate donor assignment of dd-cfDNA is methodologically challenging in re-transplantation scenarios.
Purpose of the Study:
- To evaluate a novel next-generation sequencing (NGS)-based dd-cfDNA assay.
- To determine the assay's ability to accurately identify the source of dd-cfDNA.
- To assess performance in both artificial and clinical samples from patients with sequential kidney transplants.
Main Methods:
- Utilized a new next-generation sequencing (NGS) based dd-cfDNA assay.
- Tested the assay with artificially generated chimeric samples.
- Analyzed clinical samples from 31 patients with two sequential kidney transplants.
Main Results:
- The NGS assay demonstrated high accuracy in quantifying and assigning dd-cfDNA in experimental samples.
- Detected dd-cfDNA from the first kidney graft in 20% of patients with sequential transplants.
- Observed dd-cfDNA from the first graft in the 0.1%-0.6% range, with temporal fluctuations.
Conclusions:
- This study is the first to report dd-cfDNA assay use for multiple kidney transplants.
- A significant fraction of transplant patients show detectable dd-cfDNA from prior grafts.
- The detected dd-cfDNA levels are clinically relevant and may impact treatment decisions.
