Diagnostic Performance of Donor-Derived Cell-Free DNA Assay (AlloSure®) in Kidney Transplant Recipients with Graft Dysfunction: A Single Center Study
1Transplant, John C. McDonald Regional Transplant Center - Willis Knighton Health System, Shreveport, LA, 2John C. McDonald Regional Transplant Center - Willis Knighton Health System, Shreveport, LA
Meeting: 2022 American Transplant Congress
Abstract number: 1676
Keywords: Biopsy, Kidney transplantation, Non-invasive diagnosis, Rejection
Topic: Clinical Science » Kidney » 34 - Kidney: Acute Cellular Rejection
Session Information
Session Name: Kidney: Acute Cellular Rejection
Session Type: Poster Abstract
Date: Tuesday, June 7, 2022
Session Time: 7:00pm-8:00pm
Presentation Time: 7:00pm-8:00pm
Location: Hynes Halls C & D
*Purpose: Circulating donor-derived cell-free DNA (dd-cf-DNA) is a non-invasive biomarker of kidney allograft injury with a high negative predictive value for ruling out active rejection in patients with evidence of graft dysfunction. At our center, we compared the AlloSure® (CareDx®) test for the dd-cf-DNA assays using >1% as the cut-off value, as suggested by the DART study, against the gold standard biopsy results and calculated its performance metrics.
*Methods: From Dec 2019 to Oct 2020, we found 16 patients who had their 21 AlloSure® assays drawn, which were within a week of for-cause biopsy sampling. In assessing the cause of 21 biopsy samples, 20 had AKI, 5 had proteinuria, and 3 had clinical symptoms of volume overload.
*Results: AlloSure® and biopsy results were concordant in 14/21 (66.7%) samples [Table 1]. Of the 21 for-cause biopsies, 8 biopsies were positive for rejection (2 borderline, 1 TCMR, 3 AMR, 1 mixed AMR/TCMR, 1 chronic). AlloSure® was positive in 2 of these rejections (1 TCMR, 1 mixed AMR/TCMR). However, it was false-negative in the other 6 rejections. Out of the 13 negative biopsy results, AlloSure® was negative in 12 samples and false-positive in one sample. The performance metrics in this patient population were: sensitivity 25%, specificity 92.3%, positive and negative predictive values of 66.7%, and accuracy of 66.7%.
| Biopsy | ||||
| Positive | Negative | Total | ||
| AlloSure® | Positive | 2 | 1 | 3 |
| Negative | 6 | 12 | 18 | |
| Total | 8 | 13 | 21 |
*Conclusions: Although we had a small sample size, it can be concluded from this study that AlloSure® has a high specificity to diagnose graft rejection in kidney transplant recipients.
To cite this abstract in AMA style:
Naseer MS, Shokouh-Amiri H, Creamer T, McMillan R, Tandukar S, Aultman D, Zibari GB, Singh N. Diagnostic Performance of Donor-Derived Cell-Free DNA Assay (AlloSure®) in Kidney Transplant Recipients with Graft Dysfunction: A Single Center Study [abstract]. Am J Transplant. 2022; 22 (suppl 3). https://atcmeetingabstracts.com/abstract/diagnostic-performance-of-donor-derived-cell-free-dna-assay-allosure-in-kidney-transplant-recipients-with-graft-dysfunction-a-single-center-study/. Accessed May 16, 2025.« Back to 2022 American Transplant Congress