At present, while there are innovative non-invasive biomarkers developed to diagnose acute rejection, there are no sufficiently reliable non-invasive biomarkers to assess the lesional state of the graft. Serum creatinine is not specific for renal allograft injury and does not clearly distinguish loss of function from acute rejection from another cause. In parallel, with the emergence of molecular biology technologies such as Next-Generation Sequencing (NGS), another approach using the quantification of Single Nucleotides Polymorphisms (SNPs) present on the donor's circulating DNA (dd-cfDNA) has been studied. . Data from several studies suggest that dd-cfDNA levels in blood and urine can detect rejection in heart, lung, liver and kidney allografts. However, it is currently not possible to identify the cellular origin of graft damage with these technologies. To make a diagnosis on the type of rejection, the use of solid biopsy is mandatory. The Banff classification established by different consortia is used as a reference method to characterize and diagnose the typology of renal transplant rejection.