Abstract: PO2401
Protocol-Based Donor-Derived Cell-Free DNA Surveillance in Kidney Transplant Recipients: A Single-Center Experience
Session Information
- Clinical and Immunologic Predictors of Post-Transplant Outcomes
October 22, 2020 | Location: On-Demand
Abstract Time: 10:00 AM - 12:00 PM
Category: Transplantation
- 1902 Transplantation: Clinical
Authors
- Nissaisorakarn, Pitchaphon, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States
- Patel, Het, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States
- Pavlakis, Martha, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States
- Aala, Amtul, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States
- Agrawal, Nikhil, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States
Background
Kidney biopsy is invasive and has limited utility when used as a surveillance test post-transplant. Donor-derived cell-free DNA (dd-cfDNA) surveillance testing has never been studied in comparison with other routinely performed surveillance tests.
Methods
Our transplant center implemented the dd-cfDNA (Allosure ®) surveillance protocol (1,2,3,4,6 months and then quarterly post-op) in kidney transplant recipients starting July 2018, in addition to our existing protocol measurements of serum Cr, proteinuria and DSA.
We retrospectively reviewed all kidney alone transplant recipients transplanted between July 2018- April 2020. Data collection was done at time of dd-cfDNA surveillance and included: dd-cfDNA (positive if >1% dd-cfDNA), elevated Cr (≥0.3mg /dL from Baseline), elevated proteinuria (≥0.3 mg/dL from baseline), DSA (if available).
Results
366 screening dd-cfDNA test results were reviewed from 84 patients. There were 13/366 positive dd-cfDNA tests in 8/84 patients.
5 of the 8 patients underwent a kidney biopsy which showed: 4 rejections (2 humoral, 2 cellular) (for 1 patient who had cellular rejection, dd-cfDNA test was the only surveillance test that was positive) and 1 ATN (dd-cfDNA test was borderline positive at 1.0%). The remaining 3 patients did not undergo a biopsy and repeat dd-cfDNA testing improved without intervention.
In the 353/366 negative dd-cfDNA tests in 76 patients: 8 patients underwent a biopsy: 2 patients who had increased Cr showed borderline acute cellular rejection, 3 had recurrent disease (MPGN, DM, IgAN) and 3 showed ATN/Vascular disease/IFTA. In the 2 patients with borderline acute cellular rejection dd-cfDNA was <0.7%.
Conclusion
We found that the addition of surveillance dd-cfDNA testing to current testing algorithm was able to identify rejection in 1 patient, when others surveillance tests were negative. A negative result may obviate the need for biopsy, including protocol biopsies in centers who perform them.
| No biopsy performed | Biopsy Performed | ||
| Rejection | No rejection | ||
| dd-cfDNA positive | 8 | 4 | 1 |
| dd-cfDNA negative | 343 | 2 (borderline ACR) | 8 |
| Total | 351 | 15 | |
| Standard protocol positive | 33 | 5 | 6 |
| Standard protocol negative | 318 | 1 | 3 |
| Total | 351 | 15 | |
Funding
- Commercial Support – CareDx