Goh Su Kah, Do Hongdo, Testro Adam, Pavlovic Julie, Vago Angela, Lokan Julie, Jones Robert M, Christophi Christopher, Dobrovic Alexander, Muralidharan Vijayaragavan
Department of Surgery, The University of Melbourne, Austin Health, Heidelberg, VIC, Australia.
Translational Genomics and Epigenomics Laboratory, Olivia Newton-John Cancer Research Institute, Heidelberg, VIC, Australia.
Transplant Direct. 2019 Jun 21;5(7):e462. doi: 10.1097/TXD.0000000000000902. eCollection 2019 Jul.
Assessment of donor-specific cell-free DNA (dscfDNA) in the recipient is emerging as a noninvasive biomarker of organ rejection after transplantation. We previously developed a digital polymerase chain reaction (PCR)-based approach that readily measures dscfDNA within clinically relevant turnaround times. Using this approach, we characterized the dynamics and evaluated the clinical utility of dscfDNA after liver transplantation (LT).
Deletion/insertion polymorphisms were used to distinguish donor-specific DNA from recipient-specific DNA. Posttransplant dscfDNA was measured in the plasma of the recipients. In the longitudinal cohort, dscfDNA was serially measured at days 3, 7, 14, 28, and 42 in 20 recipients. In the cross-sectional cohort, dscfDNA was measured in 4 clinically stable recipients (>1-y posttransplant) and 16 recipients (>1-mo posttransplant) who were undergoing liver biopsies.
Recipients who underwent LT without complications demonstrated an exponential decline in dscfDNA. Median levels at days 3, 7, 14, 28, and 42 were 1936, 1015, 247, 90, and 66 copies/mL, respectively. dscfDNA was higher in recipients with treated biopsy-proven acute rejection (tBPAR) when compared to those without. The area under the receiver operator characteristic curve of dscfDNA was higher than that of routine liver function tests for tBPAR (dscfDNA: 98.8% with 95% confidence interval, 95.8%-100%; alanine aminotransferase: 85.7%; alkaline phosphatase: 66.4%; gamma-glutamyl transferase: 80.1%; and bilirubin: 35.4%).
dscfDNA as measured by probe-free droplet digital PCR methodology was reflective of organ health after LT. Our findings demonstrate the potential utility of dscfDNA as a diagnostic tool of tBPAR.
评估受者体内供体特异性游离DNA（dscfDNA）正逐渐成为移植后器官排斥反应的一种非侵入性生物标志物。我们之前开发了一种基于数字聚合酶链反应（PCR）的方法，该方法能够在临床相关的周转时间内轻松测量dscfDNA。利用这种方法，我们对肝移植（LT）后dscfDNA的动态变化进行了特征分析，并评估了其临床应用价值。
利用缺失/插入多态性来区分供体特异性DNA和受者特异性DNA。在受者血浆中测量移植后的dscfDNA。在纵向队列中，对20名受者在第3、7、14、28和42天连续测量dscfDNA。在横断面队列中，对4名临床稳定的受者（移植后>1年）和16名正在接受肝活检的受者（移植后>1个月）测量dscfDNA。
未发生并发症的LT受者dscfDNA呈指数下降。第3、7、14、28和42天的中位数水平分别为1936、1015、247、90和66拷贝/毫升。与未发生活检证实的急性排斥反应（tBPAR）的受者相比，发生tBPAR的受者dscfDNA水平更高。dscfDNA的受试者工作特征曲线下面积高于tBPAR的常规肝功能检查（dscfDNA：98.8%，95%置信区间为95.8%-100%；丙氨酸转氨酶：85.7%；碱性磷酸酶：66.4%；γ-谷氨酰转移酶：80.1%；胆红素：35.4%）。
通过无探针液滴数字PCR方法测量的dscfDNA反映了LT后的器官健康状况。我们的研究结果证明了dscfDNA作为tBPAR诊断工具的潜在应用价值。
