Biomarkers in acute kidney injury and cirrhosis

The use of biomarkers for managing acute kidney injury (AKI) is still not routinely used in clinical practice due to the lack of robust evidence on their impact on patient outcomes. In cirrhotic patients’ serum creatinine (sCr) limitations are more pronounced, as malnutrition, altered volume status, and muscle mass loss are more frequently encountered. This can make the diagnosis of AKI challenging, and therefore, additional markers may be necessary for a more accurate evaluation. This review will discuss the renal biomarkers of filtration and injury in patients with cirrhosis, focusing on their possible clinical application. A combined evaluation of a panel of biomarkers could provide a comprehensive assessment of kidney function and help distinguish between hepatorenal syndrome and chronic kidney disease in situations involving liver or combined liver and kidney transplantation. We will demonstrate that some biomarkers have more evidence of their utility in cirrhotic patients, such as cystatin C for filtration. In contrast, others require further studies, such as proenkephalin, which is only used in liver transplantation and appears superior to cystatin C as the inflammatory state does not influence it in cirrhotic patients. Interleukin-18 (IL-18) as a biomarker of injury in renal dysfunction in cirrhotic patients is still unclear despite extensive analysis in various scenarios, including liver diseases. On the other hand, the utility of neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) is well established in renal dysfunction and evaluating other outcomes.