Study of Accuracy of NGAL, a Renal Injury Biomarker, in Patients With Cirrhosis

Inclusion Criteria: * Cirrhosis diagnosis by liver biopsy or combination of clinical, laboratorial, endoscopic and imagenological data; * Presence of ascites and/or hepatic hydrothorax; * Age over 18 years old; * Diagnosis of bacterial infection (including spontaneous bacterial peritonitis and others) with or without acute kidney injury (defined as a serum creatinine above 1.5mg/dL at admission) or acute kidney injury without bacterial infection; * Agreement to participate in the study, registered by informed consent; Exclusion Criteria: * Serious comorbidities (functional class IV heart failure, O2 dependent chronic obstructive pulmonary disease, advanced cancer); * Shock, as defined by American College of Chest Physicians; * Chronic kidney disease with serum creatinine persistently above 1.5mg/dL in the previous 6 months and/or with sonographic findings of chronic nephropathy; * Intrinsic nephropathy with hematuria over 50 red cells/high power field and dysmorphic erythrocyte and/or proteinuria over 500mg/24h; * Use of nephrotoxic drugs in the previous 30 days; * Dialysis prior to study inclusion; * Previous solid organ transplantation.