Neutrophil Gelatinase Associated Lipocalin (NGAL) – a biomarker of renal dysfunction in patients with liver cirrhosis: Do we have enough proof?

Rationale. Renal dysfunction has a serious impact on the natural evolution of liver cirrhosis. Treatment and prognosis may be improved if an early diagnosis could be established, and specific therapeutic interventions would be applied. Although RIFLE and AKIN classifications have been successfully implemented in the clinical practice of Nephrology and Intensive Care Units, these did not provide major improvements in patients with liver cirrhosis. In the last decade, various biomarkers of kidney injury have been assessed, and Neutrophil Gelatinase-Associated Lipocalin (NGAL) is one of the most promising and most studied novel biomarker. Objective. To offer a brief evaluation on current data on the utility of this biomarker in patients with liver cirrhosis. Methods and results. We have searched through current literature and analyzed all significant full text articles on this topic. Discussions. NGAL and other new kidney injury molecules may be useful in patients with liver cirrhosis, particularly in identifying structural kidney dysfunction, but larger validation studies to confirm this observation are needed. Abbreviations: ADQI = Acute Dialysis Quality Initiative, AKI = acute kidney injury, AKIN = Acute Kidney Injury Network, ATN = acute tubular necrosis, CKD = chronic kidney disease, Cys C = cystatin C, GFR = glomerular filtration rate, HRS = hepatorenal syndrome, IAC = International Ascites Club, IL-18 = interleukin-18, KIM-1 = kidney injury molecule-1, L-FABP = liver-type fatty acid-binding protein, LT = liver transplantation, MDRD6 = Modification of Diet in Renal Disease 6, NAG = N-acetyl-β-D-glucosaminidase, NGAL = Neutrophil Gelatinase-Associated Lipocalin, pi-GST = pi-glutathione S-transferase, PRA = prerenal azotemia, RBP = retinol binding protein, RRT = renal replacement therapies, SCr = serum creatinine, SLKT = simultaneous liver and kidney transplant, UO = urine output, γ-GT = γ-glutamyl transpeptidase