STUDY OF URINARY NEUTROPHIL GELATINASE-ASSOCIATED LIPOCALIN (NGAL) IN PATIENTS WITH LIVER CIRRHOSIS AND ITS RELATION TO HEPATORENAL SYNDROME

Abstract

Background: Hepatorenal syndrome (HRS) is a unique form of kidney injury resulting from renal vasoconstriction in the setting of systemic and splanchnic arterial vasodilatation in patients with advanced cirrhosis. Neutrophil gelatinase-associated lipocalin (NGAL) is a proved biomarker of acute and chronic renal injury. Aim of the work was to study urinary NGAL level in patients with liver cirrhosis and its relation to HRS. Subjects and methods: The study included 5 groups; group I (15 patients with cirrhosis, no ascites and normal renal function), group II (15 patients with cirrhosis, ascites and normal renal function), group III (15 patients with cirrhosis, ascites and HRS), group IV (15 patients with cirrhosis, ascites and chronic kidney disease; CKD) and group V (15 healthy subjects) as control group. The diagnosis of HRS was based on the International Ascites Club criteria. The glomerular filtration rate (GFR) was calculated using 2 formulas: The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and the Extended Modification of Diet in Renal Disease (Ext-MDRD) formula. Urinary level of neutrophil gelatinase lipocalin (NGAL) was done using ELISA, and neutrophil gelatinase associated lipocalin/ urinary creatinine concentration (NGAL/UCC) ratio was calculated. Results: Both NGAL level and NGAL/UCC ratio increased significantly in cirrhotic patient with HRS, while only NGAL/UCC ratio significantly increased in cirrhotics with CKD compared to normal controls and to cirrhotics with normal serum creatinine. NGAL level and NGAL/UCC ratio were higher in HRS compared to CKD cirrhotics, they could successfully identify HRS at cut-off values of 100 ng/ml and 0.9, respectively. Both markers correlated with each other and with blood urea, serum creatinine, estimated GFR, and Child-Pugh score of patients. Conclusion: Urinary NGAL level and NGAL/UCC ratio can be used as markers for early detection of HRS among patients with cirrhosis. However, the elevation of NGAL in the setting of HRS confirms the speculation that HRS entails a degree of structural kidney injury rather than being purely functional. Larger studies with higher number of patients are needed to investigate the value of urinary NGAL in type I and type II HRS separately, and to examine the role of other markers for early detection of HRS to improve its prognosis. Key Words: Hepatorenal syndrome: HRS, Neutrophil gelatinase-associated lipocalin: NGAL, chronic kidney disease: CKD, the Chronic Kidney Disease Epidemiology Collaboration: CKD-EPI, the Extended Modification of Diet in Renal Disease: Ext-MDRD, neutrophil gelatinase associated lipocalin/ urinary creatinine concentration: NGAL/UCC .