New biomarkers of acute kidney injury.

Acute kidney injury (AKI) represents a major clinical problem, with rising incidence and high mortality rate. The lack of early biomarkers has resulted in a delay in initiating therapies. Fortunately, the tools of modern science have revealed promising novel biomarkers for AKI, with potentially high sensitivity and specificity. These include a plasma panel (neutrophil gelatinase-associated lipocalin and cystatin C) and a urine panel (neutrophil gelatinase-associated lipocalin, interleukin 18, and kidney injury molecule-1). Because they represent sequential biomarkers, it is likely that the AKI panels will be useful for timing the initial insult and assessing the duration of AKI (analogous to the cardiac panel for evaluating chest pain) and for predicting overall prognosis with respect to dialysis requirement and mortality. It is also likely that the AKI panels will help distinguish between the various types and pathogeneses of AKI. It will be important in future studies to validate the sensitivity and specificity of these biomarker panels in clinical samples from large cohorts and from multiple clinical situations. Such studies will be markedly facilitated by multidisciplinary participation of various specialties (intensivists, cardiologists, surgeons) in AKI clinical studies and by the availability of commercial tools for the reliable and reproducible measurement of biomarkers across different laboratories.