The Importance of Neutrophil Gelatinase-Associated Lipocalin and Liver Type Fatty Acid Binding Protein in Acute Kidney Injury

Abstract

Background: The most important factor in the diagnosis of AKI is to accurately and early detect the damage that occurs in the kidney before the filtration capacity of the kidney decreases. Therefore, we discussed the use of NGAL and L-FABP in the early diagnosis of acute kidney injury, evaluation of clinical severity and prognosis as well as prediction of hemodialysis decision in this prospective study. Methods: We studied 82 participants which included 41 patients aged 18 years and older with the diagnosis of acute kidney injury. We compared the renal function tests collected at 0 and 6 hours with the plasma NGAL and LFABP levels measured using ELISA. Acute kidney injury was defined as serum creatinine increase of 0.3 mg/dL in the last 48 hours, or an increase more than 1.5 times, or an increase in the basal serum creatinine value in the last seven days, or less than 0.5/mL/kg of urine volume within six hours. We tested the power of these new biomarkers in the early diagnosis, and prediction of hemodialysis and survival of the patients with AKI using ROC analysis. Results: Fifteen (36.6%) of the patients were anuric and 26 (63.4%) were oliguric. Twenty-one (51.2%) patients were KDIGO Stage 3. Seventeen (41.5%) patients underwent hemodialysis. In the patient group, the mean NGAL level was 289.7 +/- 117.4 ng/mL and the mean L-FABP level was 232.7 +/- 72.8. Eleven (26.9%) of 41 patients died within the first 24 hours. In the dead patients, the mean plasma NGAL level was statistically significantly high (p = 0.005). The mean NGAL level was found to be statistically increased in correlation with the severity of acute kidney injury in patients (p < 0.05). To predict acute kidney injury, the ROC analysis showed that the area under the curve (AUC) was 0.819 (95% confidence interval (CI): 0.729 -0.909) (p < 0.001) for plasma NGAL level, and the area under the curve (AUC) was 0.891 (95% confidence interval (CI): 0.822 -0.959) for plasma L-FABP level (p < 0.001). Conclusions: Our study provides evidence that NGAL and L-FABP are effective biomarkers for early detection of AKI as well as predicting clinical severity and hemodialysis.