Evaluation of NGAL Test™, a fully-automated neutrophil gelatinase-associated lipocalin (NGAL) immunoassay on Beckman Coulter AU 5822

Background: The neutrophil gelatinase associated lipocalin (NGAL) has been identified as the most promising biomarker of acute kidney injury (AKI). This study was aimed to evaluate a NGAL immunoassay on Beckman Coulter AU 5822. Methods: NGAL Test (TM) (BioPorto Diagnostics A/S) is a particle-enhanced turbidimetric immunoassay. The within- and between-run imprecision were assessed on three urine samples. The linearity was assessed by serially diluting two urine samples with low and high NGAL concentration. The comparison study was performed with Abbott ARCHITECT NGAL, on 70 urine samples. Results: The within-run imprecision was comprised between 1.0% and 2.3%, whereas the between-run imprecision was between 1.2% and 2.0%. The linearity was excellent in the range between 18 ng/mL and 790 ng/mL (r=1.000; p < 0.001). A highly significant agreement was observed between NGAL Test (TM) on Beckman Coulter AU5822 and Abbott ARCHITECT NGAL (r=0.925; p < 0.001), although the method exhibited a bias of +65%. Excellent sensitivity and specificity against the ARCHITECT values were found at 200 ng/mL. Conclusions: This analytical evaluation attests that the NGAL Test (TM) has several technical and analytical advantages, including no manual pretreatment, low volume of sample (i.e., 3 mu L), fast turnaround time (approx. 10 min), low imprecision, wide dynamic range, optimal linearity.