M. Moein1, J. P. Settineri1, H. Suleiman1, J. Sidhu1, S. Papa1, R. Hod Dvorai1, A. Bahreini1, A. Luo1, R. Saidi1 1SUNY Upstate Medical University, Surgery/Transplantation, Syracuse, NY, USA
Introduction: Transcriptomic kidney profile testing and donor-derived cell-free DNA (dd-cfDNA) testing are newly introduced and have been shown to provide an early marker of graft inflammation during the post-transplant period. This study focused on utilizing clinical data to evaluate the application of the transcriptomic kidney profile test and dd-cfDNA test in terms of rejection detection by comparing the tests results to the kidney biopsy.
Methods: We conducted a retrospective analysis of a prospectively collected database of all adult kidney transplant patients at a single center from 1 January 2014 to 1 December 2022. Our inclusion criteria were patients who have a concurrent transcriptomic kidney profile test and kidney biopsy results.
Results: The overall number of kidney transplant rejections identified by biopsy was 33 (24.3%) for the whole cohort. 14 (42.4%) ABMR, 12 (36.4%) TCMR, and 7 (21.2%) mix ABMR and TCMR were diagnosed. The transcriptomic kidney profile test had a 52.83% positive predictive value (PPV) and 92.77% negative predictive value (NPV) for diagnosis of a rejection in the kidney allograft. In our study cohort, the transcriptomic kidney profile test showed an 82.35% sensitivity and 75.49% specificity. The dd-cfDNA test had a 54.83% positive predictive value (PPV) and 86.45% negative predictive value (NPV) for diagnosis of a rejection in the kidney allograft. In our study cohort, the dd-cfDNA test showed a 56.66% sensitivity and 85.56% specificity. The combined positive transcriptomic kidney profile and dd-cfDNA tests could detect 17 (51.51%) of the total 33 rejections. Negative transcriptomic kidney profile and dd-cfDNA tests were observed in 66 (70.21%) of the biopsies that did not report a rejection.
Conclusion: Although there are certain discrepancies and limitations, we believe that the transcriptomic profile test and dd-cfDNA test can be used for detecting rejections at an early stage to help shape patient management. The dd-cfDNA test, in particular, helps avoid the invasive interval biopsies. Following a negative test result, the probability that the patient is not having any form of rejection is 86.45%. The transcriptomic profile test’s high sensitivity and a specificity allow us to pick up cases that may have otherwise not been detected as rejection on biopsy.
