Neutrophil Gelatinase-Associated Lipocalin (NGAL): An Early Dual Biomarker in Diagnosis of Ascitic Fluid Infection and Acute Kidney Injury in Liver Cirrhosis in a Tertiary Centre, Egypt

Abstract

Background: This study aimed to evaluate the ascitic Neutrophil gelatinase-associated lipocalin (NGAL) as a diagnostic biomarker for bacterial translocation or bactDNA translocation in ascites of cirrhotic patients and to evaluate the urinary NGAL for identifying renal dysfunction in patients with liver cirrhosis. Methods: This study included 44 patients with ascites.  Study participants were divided into two groups. Group (1) had 22 patients with neutrocytic ascites and/or positive ascitic fluid (AF) culture while group (2) included 22 patients with culture negative non neutrocytic ascites (CNNNA), recruited as controls. AF and urine samples were collected from all studied participants. ELISA kit was used for measurement of NGAL levels in AF and urine. DNA extraction and PCR were done. Results: Values of NGAL in ascitic fluid were statistically significantly higher in bactDNA positive group. At cutoff 143.9 ng/ml, ascites NGAL had 86.4% sensitivity, 45.5% specificity, 61.3% positive predictive value (PPV) and 76.9% negative predictive value (NPV). When comparing ascites NGAL between bactDNA positive and negative group, NGAL has a sensitivity of 86.2% and a specificity of 46.7%, PPV of 75.8%, NPV of 63.6%. As for urine NGAL, patients with AKI had statistically significant higher levels of NGAL. Urine NGAL achieved sensitivity of 77.3%, specificity of 50%, PPV of 60.7%, NPV of 68.75%. Conclusion: Early and accurate diagnosis of BT or bactDNA translocation  can be aided by utilizing NGAL especially in ruling out infection in those reported to have negative culture results, besides, it can help in early detection of complication of cirrhosis and infection especially AKI helping in the improving the prognosis of cirrhotic patients. It is an advantage that a single marker can detect both infection and kidney injury.