Performance of Donor Derived Cell Free DNA (dd-cfDNA) in Diagnosing Subclinical and Clinical Acute Rejection in Kidney Transplant Recipients
Eurofins, Framingham, MA
Meeting: 2022 American Transplant Congress
Abstract number: 1396
Keywords: Graft function, Graft survival, Kidney, Protocol biopsy
Topic: Clinical Science » Kidney » 41 - Kidney Technical
Session Information
Session Time: 7:00pm-8:00pm
Presentation Time: 7:00pm-8:00pm
Location: Hynes Halls C & D
*Purpose: The aim of this study was to examine the performance of Viracor TRAC donor derived cell free DNA (dd-cfDNA) in for-cause biopsies as well as protocol biopsies.
*Methods: This was a retrospective analysis of 605 dd-cfDNA samples from kidney transplant recipients. The samples came from patients with stable serum creatinine undergoing protocol biopsies (n=428) as well as unstable patients requiring for-cause biopsies (n=177). Next generation sequencing was used to determine the percentage of dd-cfDNA in recipient plasma post-transplant. Viracor TRAC (Transplant Rejection Allograft Check) dd-cfDNA assay queries > 100,000 single nucleotide polymorphisms (SNPs) to accurately quantify dd-cfDNA percentage in SOT patients.
*Results: Performance of the assay is shown in Table 1. The overall negative predictive value (NPV) and positive predictive value (PPV) were 82.56% and 52.73%, respectively, adjusted to 25% prevalence. When examining samples from for-cause biopsies the NPV and PPV were 80.41% and 46.36%, respectively. Performance from protocol biopsy samples provided a NPV of 83.42% and PPV 54.80%, respectively.
*Conclusions: This is the first large scope study examining dd-cfDNA values in both for cause and protocol biopsy samples. For renal transplantation, many publications of dd-cfDNA have validated the use in the clinical context of suspicion of allograft rejection. Data in patients with stable serum creatinine is limited. Surveillance biopsies for stable patients have logistical limitations and are not performed in most transplant centers. The strength of dd-cfDNA assays like Viracor TRAC lie in the NPV, being able to confidently rule out rejection. The test performance to rule out rejection was consistent in for-cause biopsy scenarios as well as protocol biopsies. The PPV however remains low in both contexts. Of note, performance is enhanced when looking at AMR compared to ACR. When dd-cfDNA assays are used alone, their clinical utility is limited to ruling out rejection.
To cite this abstract in AMA style:
Cober T, West-Thielke P, Miller C, Grund N, Altrich M, Sutton A, Sinha R, Miller M, Kleiboeker S, Weems J. Performance of Donor Derived Cell Free DNA (dd-cfDNA) in Diagnosing Subclinical and Clinical Acute Rejection in Kidney Transplant Recipients [abstract]. Am J Transplant. 2022; 22 (suppl 3). https://atcmeetingabstracts.com/abstract/performance-of-donor-derived-cell-free-dna-dd-cfdna-in-diagnosing-subclinical-and-clinical-acute-rejection-in-kidney-transplant-recipients/. Accessed May 6, 2025.« Back to 2022 American Transplant Congress