Diagnostic accuracy of urinary neutrophil gelatinase-associated lipocalin in patients with septic acute kidney injury

BACKGROUND Sepsis is the most common cause of acute kidney injury (AKI). Very few studies have investigated the predictive properties of urinary neutrophil gelatinase-associated lipocalin (uNGAL) as a marker of AKI in septic patients. The aim of this study is to examine uNGAL in septic patients with and without AKI and to evaluate its predictive value. METHODS We prospectively studied 155 patients with sepsis over a period of 1 year. Urine was analyzed for neutrophil gelatinase-associated lipocalin at 12, 24, and 48 hours after admission. Patients with <24-hour stay and those with chronic kidney disease were excluded. AKI was classified according to the Acute Kidney Injury Network guidelines. RESULTS The differences in mean change of uNGAL at 12, 24, and 48 hours were 80.00±7.00 ng/mL and 128.13±22.46 ng/mL, respectively in septic AKI, and 02.07±0.80 ng/mL and 26.13±15.12 ng/mL, respectively in septic non-AKI. At baseline or 12 hours, the cutoff value of 34.32 ng/mL had a sensitivity and specificity of 86.36 and 80.60, respectively and an area under curve of 0.81 (95% CI: 0.73-0.89) for predicting AKI. At the cutoff value 199.99 ng/mL sensitivity and specificity of 90.0 and 64.66, respectively and an area under curve of 0.82 (95% CI, 0.75-0.88) for predicting AKI. CONCLUSION The baseline or 12-hour uNGAL is highly sensitive but a less specific predictor of AKI in septic patients.