Session Name: Pancreas and Islet: All Topics
Session Date & Time: None. Available on demand.
*Purpose: Increased level of donor-derived cell-free DNA (dd-cfDNA) has proven to be a sensitive marker for allograft rejection after solid organ transplant, particularly heart and kidney; the aim of this study was to determine the role of dd-cfDNA in diagnosing rejection after simultaneous pancreas-kidney (SPK) transplant.
*Methods: We performed a single-center prospective cohort study of all SPK recipients starting in November 2019. Dd-cfDNA was measured using AlloSure (CareDx, Inc. Brisbane CA). Rejection events were diagnosed either clinically or with biopsy, and are specified in the results. Median values are provided with the interquartile range (IQR) for larger samples or the range when n ≤ 10. Delta values were calculated using the dd-cfDNA value at the time of the rejection event and the lowest value prior to the event. Correlation between dd-cfDNA and lipase was determined by Pearson’s correlation coefficient.
*Results: 43 patients were included for analysis. Median number of dd-cfDNA visits per patient was 10, with 366 visits in total. In patients without rejection, median dd-cfDNA across all visits was 0.2% (n=290, IQR 0.15% – 0.39%). Among patients who were treated for rejection (n=8), median dd-cfDNA at the time of event was 3.5% (range 1.2% – 7.4%), and median delta dd-cfDNA was 506% (range 45% – 3764%). Of the 8 rejection events, 5 were diagnosed clinically and 3 were confirmed with biopsies, which demonstrated antibody mediated rejection (AMR) in kidney, AMR in kidney and pancreas, and mixed AMR/cellular rejection in pancreas. Their dd-cfDNA values were 1.6%, 3.2%, and 3.7%, respectively. 10 additional biopsies were performed which did not demonstrate rejection. At the time of negative biopsy, median dd-cfNDA was 0.37% (range 0.12% – 0.65%). Across all patients, there was a weak correlation between lipase and dd-cfDNA (r=0.25, p<0.0001). Notably, one patient with biopsy-confirmed pancreas rejection demonstrated lipase = 22 and dd-cfDNA = 3.2%. Conversely, another patient with lipase = 1100 and dd-cfDNA = 0.55% was biopsied and found to have pancreatitis.
*Conclusions: Dd-cfDNA demonstrates promise in differentiating allograft rejection from non-rejection events in SPK recipients. Prospective surveillance of dd-cfDNA should be considered in this population, and could provide data for further investigation.
To cite this abstract in AMA style:Williams M, Ghosh S, Jenkins LL, Hertl M, Saltzberg S, Peev V, Chan E, Hollinger E, Schadde E, Olaitan O. Donor Derived Cell Free DNA Identifies Rejection in Simultaneous Pancreas Kidney Transplant Recipients [abstract]. Am J Transplant. 2021; 21 (suppl 3). https://atcmeetingabstracts.com/abstract/donor-derived-cell-free-dna-identifies-rejection-in-simultaneous-pancreas-kidney-transplant-recipients/. Accessed September 27, 2021.
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