A Reliable Non Invasive Alternative to Surveillance Renal Allograft Biopsy
Transplant Nephrology, University of Alabama Birmingham, Birmingham, AL
Meeting: 2021 American Transplant Congress
Abstract number: 644
Keywords: Kidney, Monitoring, Protocol biopsy, Rejection
Topic: Clinical Science » Biomarkers, Immune Assessment and Clinical Outcomes
Session Information
Session Name: Biomarkers, Immune Assessment and Clinical Outcomes
Session Type: Poster Abstract
Session Date & Time: None. Available on demand.
Location: Virtual
*Purpose:
Surveillance Renal Allograft Biopsy (SAVB) is the standard of care to identify subclinical immunological injury(SCI). However fewer than 25% of transplant centers in the US perform SVAB, as it has a low rate of positive results, involves procedure risks, and has logistical issues. Donor derived cell free DNA (dd-cfDNA) is gaining acceptance as a non-invasive biomarker of immunological injury in renal allografts with a negative predictive value (NPV) exceeding 84%. We propose using a combination of dd-cfDNA and DSA to enhance the NPV as an alternative to SVAB .
*Methods: Retrospective, single center chart review of 174 consecutive patients undergoing SVAB between 02/02/2019 to 09/20/2020 with paired results of dd-cfDNA and DSA.Data regarding patient demographics, induction agents, etiology of ESRD and CPRA status was collected.
| dd-cf DNA | >1% |
| DSA | >1500 Mfi |
| Biopsy | Cellular Rejection(Banff Borderline or higher) and/or Antibody Mediated Rejection |
*Results: Patient characteristics were comparable to most Renal Transplant centres in the US.Using dd-cf DNA for diagnoses has a higher specificity of 93% at the expense of missing 2.29% patients who could have SCI on SVAB.
| SVAB Positive | SVAB Negative | |
| dd-cf DNA Positive | 4 TP | 11 FP |
| dd-cf DNA Negative | 7 FN(2%) | 152 TN(87%) |
Combination of dd-cf DNA with DSA has NPV of 98% and could safely avoid SVAB in up to 77% of the population with a chance of missing SCI in only 1.72% of patients
| SVAB Positive | SVAB Negative | |
| dd-cf DNA or DSA Positive | 8 TP | 29 FP |
| dd-cf DNA and DSA Negative | 3 FN(1.72%) | 134 TN(77%) |
| Sensitivity | Specificity | PPV | NPV | Accuracy | |
| dd-cf DNA | 36% | 93% | 27% | 96% | 90% |
| dd-cf DNA + DSA | 73% | 82% | 22% | 98% | 82% |
*Conclusions:
Use of dd-cfDNA is a useful screen for SCI after transplant with a high NPV. Adding DSA to dd-cfDNA further improves the NPV to 98%. Thus, a combination of negative dd-cfDNA & DSA can be used as a safe non invasive alternative to SVAB.
To cite this abstract in AMA style:
Jain R, Thaduri S, Kumar V, Kew C, Julian B, Towns G, Ong S, Ahmed F, Mehta S, Agarwal G. A Reliable Non Invasive Alternative to Surveillance Renal Allograft Biopsy [abstract]. Am J Transplant. 2021; 21 (suppl 3). https://atcmeetingabstracts.com/abstract/a-reliable-non-invasive-alternative-to-surveillance-renal-allograft-biopsy/. Accessed May 9, 2025.« Back to 2021 American Transplant Congress