Cell-free DNA (cfDNA) is released into the circulation and other body fluids as short DNA fragments through the process of cell death and cell turnover. As a consequence, cfDNA can be used to detect genetic alterations or epigenetic modifications that are specific to a given tissue, without directly accessing the tissue itself. This «liquid biopsy» approach is of particular interest in contexts where the diagnosis of pathologies commonly requires tissue biopsies, such as the monitoring of solid organ transplant recipients.
In collaboration with the Departments of Nephrology (Bern University Hospital) and Visceral Surgery (Bern University Hospital), we are investigating the detection and quantification of allograft-derived cfDNA in plasma and urine from kidney and liver recipients in order to evaluate potential applications of this «liquid biopsy» approach to improve the management and monitoring of organ transplant recipients. We are investigating different methods for detecting and quantifying allograft-derived cfDNA, including approaches based on genome sequence differences between donor and recipient, as well as approaches based on tissue-specific epigenetic modifications. Our aim is to assess and compare the clinical utility of these different approaches for the detection and monitoring of allograft pathologies.