Biomarkers of acute kidney injury

The diagnosis and follow-up of acute kidney injury (AKI) has traditionally been based on clinical parameters such as urine output, and/or biomarkers such as serum creatinine (sCr), which are not very sensitive. The identification and validation of novel biomarkers, capable of recognizing an increased risk of AKI, a renal damage before or without a functional renal loss (i.e. subclinical AKI) and a renal dysfunction prior to the increase in sCr levels, has reviewed the diagnosis and classification of AKI. Thanks to these biomarkers, a new conceptual model of AKI, that includes the full spectrum of events and conditions, has been developed. At each stage of this model, biomarkers may contribute to explain the mechanisms and to predict the clinical evolution of kidney damage. Several biomarkers have been identified. They differ in anatomical origin, physiological function, kinetics and detecting time after kidney injury. The present review describes the main biomarkers' characteristics and their role in the clinical practice.