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.