Credit: CareDx, Inc.
In solid organ transplant recipients, analysis of circulating cell-free DNA (cfDNA) offers advantages over invasive tissue biopsies for detection of rejection and immunotherapy surveillance. A by-product of cell death, cfDNA can be used to assess allograft injury by measuring donor-derived cfDNA (dd-cfDNA) against the background of recipient cfDNA. dd-cfDNA is quantified by analytically validated clinical-grade next-generation sequencing assay utilizing single nucleotide polymorphisms distributed across the genome to differentiate donor and recipient cfDNA.