NGAL (Neutrophil Gelatinase-associated Lipocalin) is an Early Predictor of Acute Kidney Injury after Cardiac Surgery and Variation of NGAL Values in Homogenous Study Subject.

ABSTRACT

Isolated CABG (coronary artery bypass grafting) has the lowest incidence of AKI (Acute Kidney Injury), followed by valvular surgery and then, combined CABG with valvular surgery. Due to the difference in baseline characteristics and in surgery type, the range of incidence is between 8.9 and 39% based on RIFLE (Risk Injury failure loss end stage kidney disease) or AKIN (Acute Kidney Injury Network) criteria. The advent of novel biomarkers of kidney injury has opened a new era of early detection and prognosis prediction for AKI. NGAL is a small molecule of 178 amino acids that belongs to the super family of lipocalins, which are proteins specialized in binding and transporting small hydrophobic molecules. The expression of NGAL raises 1000 fold in humans and rodents in response to renal tubular injury and it appears so rapidly in the urine and serum that it is useful as an early biomarker of renal failure. The role of plasma NGAL to classify AKI severity and predict the need for RRT (renal replacement therapy) after cardiac surgery has been suggested. Although study subjects were more or less from same cohort (All undergone cardiac surgery), previous studies showed that NGAL raised differently in different proportion. NGAL as an early AKI marker has successfully passed through the pre-clinical, assay development and initial clinical testing stages. It is badly need to enter in a consensus about the cutoff value of NGAL which should help the physician about leveling a case as AKI or non AKI and their consequence management.