Serum and urinary biomarkers in acute kidney transplant rejection

Background: Acute rejection (AR) is a common medical problem among kidney transplant recipients, which may cause a significant impact on patients' and allografts' survival. Kidney allograft biopsy remains the "gold standard" for assessing the cause of kidney transplant dysfunction. However, there are limitations for the allograft biopsy; these include the risk of bleeding, injury to the adjacent organs, and the possibility of sampling error leading to misdiagnosis. Methods: We conducted a comprehensive review of the literature and main published data that discussed the most relevant serum and urine biomarkers in acute allograft dysfunction, along with their clinical significance. Results: There have been significant discoveries of several important biomarkers that correlated with biopsy findings, clinical outcomes and possibly graft survival. Proteomic and genomic have been utilized in this area with some success, along with a growing discoveries of cytokines surrogate makers. Summary: The discovery of surrogate biomarkers in kidney transplantation is an evolving field of crucial importance that may change the way we practice transplant nephrology in the future.