Early diagnosis of acute kidney injury.

PURPOSE OF REVIEW The early detection of acute kidney injury may allow for timely preventive or therapeutic measures. This review discusses the role of traditional and novel biomarkers in early acute kidney injury diagnosis. RECENT FINDINGS Detection of acute kidney injury relies on changes in serum creatinine and urea. These are not ideal and do not reflect genuine injury or real-time changes in kidney function. Several novel biomarkers have emerged for early detection of acute kidney injury. Cystatin C is sensitive to early and mild changes to kidney function. Neutrophril gelatinase-associated lipocalin is expressed early after injury and has value in predicting acute kidney injury after kidney transplant and cardiopulmonary bypass. Interleukin-18 has been detected early in acute kidney injury after kidney transplant, cardiopulmonary bypass and sepsis. Kidney injury molecule-1 is upregulated after ischemic/toxic injury and has the ability to predict the need for renal replacement therapy and mortality. While heterogeneous in their expression, these biomarkers may have value as a sequential 'panel' to aid in detecting, classifying and predicting the clinical course of acute kidney injury. SUMMARY The early detection of acute kidney injury is a clinical and research priority. Traditional measures may contribute to delayed acute kidney injury diagnosis. Recent biomarkers have promise for earlier detection and for research into novel interventions.