Neutrophil gelatinase‐associated lipocalin as a diagnostic marker of acute kidney injury in pre‐eclampsia

Abstract Aim Neutrophil gelatinase‐associated lipocalin (NGAL) is an emerging biomarker for early diagnosis of acute kidney injury (AKI). This study investigated the use of urinary NGAL as a marker of AKI in women with pre‐eclampsia. Methods Urine and serum samples were collected over 24 h from 78 healthy and 109 pre‐eclamptic women, with baseline samples taken at admission to the maternity unit; NGAL was assayed in serial urine samples. Results Baseline neutrophil gelatinase‐associated lipocalin did not differ significantly between women who were healthy, those with pre‐eclampsia, or with AKI ( P = 0.55 for trend). When the pre‐eclamptic group was divided into those with eclampsia (median, 60.5 ng/mL; IQR, 23.4–173 ng/mL; n = 19), uncomplicated pre‐eclampsia (median, 18.8 ng/mL; IQR, 7.5–52.8 ng/mL; n = 48; P < 0.05 vs eclampsia), imminent eclampsia (median, 30.7 ng/mL; IQR, 13.9–49.3 ng/mL; n = 22) and pre‐eclampsia with acute kidney injury (median, 60.3 ng/mL; IQR, 23.5–159 ng/mL, n = 14), however, NGAL level did differ. On multivariate regression analysis, the only significant correlate of NGAL level was the presence of eclampsia (beta = 0.22, P < 0.05). On receiver operating characteristic curve analysis, baseline NGAL did not discriminate between subjects with or without AKI (area under the curve, 0.61; 95%CI: 0.43–0.78; P = 0.12). Conclusion Neutrophil gelatinase‐associated lipocalin level at baseline and over a 24‐h period does not provide a suitable diagnostic test for AKI in pre‐eclamptic subjects.