Utility and limitations of the use of donor-derived cell-free DNA in kidney transplantation.

In recent years, the use of new biomarkers in different phases of the diagnosis and treatment of several diseases has allowed substantial improvement in clinical practice. The use of donor-derived cell-free DNA (dd-cfDNA) in organ transplantation has led to significant progress in the treatment of post-transplant outcomes, particularly after kidney transplantation. In addition, the use of dd-cfDNA in organ transplantation has led to significant advancements in post-transplant outcome monitoring. The aim of this study is to review many of the recent studies on the use of this biomarker and to evaluate its most relevant advantages and limitations. dd-cfDNA is released from several types of cells of the transplanted organ, most often from endothelial cells and this happens in the case of organ damage, most often rejection. Its presence in the bloodstream of the recipients is an important sign of graft damage; its principal advantage is in the avoidance of invasive tools such as renal biopsy. Additionally, several studies reported that the finding of dd-cfDNA in the serum may precede histological abnormalities; its utility in the diagnosis of subclinical rejection is extremely important. Among the principal limitations of this tool are the difficulty in distinguishing different forms of graft damage. According to several studies this tool has several limitations in diagnosing T-cell mediated rejection. In addition, particular care should be taken in distinguishing dd-cfDNA from recipient-derived cfDNA.