Acute kidney injury is common in critically ill children admitted to the intensive care unit. The etiology of acute kidney injury is multifactorial and the incidence varies between 1 and 41% (Krishnamurthy, 2013) probably due to the different definitions used in clinical studies.
Unfortunately, Serum Creatinine (the main acute kidney injury biomarker used in the clinical setting) is a late marker of reduced glomerular filtration rate, which limits the ability to detect acute kidney injury early and to initiate clinical therapeutic studies. Therefore, Diagnostic specificity and sensitivity of new biomarkers are currently weighed against creatinine-based criteria (Waikar et al., 2009).
 Several proteins and biochemical markers emerged as sensitive and specific biomarkers capable of the early detection of acute tubular injury (Devarajan, 2011). The most famous of these biomarkers is neutrophil gelatinase-associated lipocalin (NGAL).