Albert C, Zapf A, Haase M, et al. - This systematic review and meta-analysis was conducted following PRISMA-IPD guidelines to determine the value of urinary and plasma NGAL (neutrophil gelatinase-associated lipocalin) for prediction of acute kidney injury (AKI) and severe AKI needing kidney dialysis (AKI-D). PubMed, Web of Science, Cochrane Library, Scopus and congress were explored to identify relevant studies. Overall, 52 observational studies with 13,040 patients were analyzed. In individual-study-data meta-analysis, AUCs of 0.75 and 0.80 for severe AKI and AKI-D, respectively, were generated for urine NGAL (uNGAL); the corresponding values for plasma NGAL (pNGAL) were 0.80 and 0.86. For uNGAL, cut-off-concentrations at 95% specificity were reported to be > 580 ng/mL with 27% sensitivity for severe AKI and > 589 ng/mL with 24% sensitivity for AKI-D. For pNGAL, corresponding cut-offs were > 364 ng/mL with 44% sensitivity and > 546 ng/mL with 26% sensitivity, respectively. Overall, in clinical research and practice, patients carrying a high risk for AKI may be identified by urinary and plasma NGAL concentrations. The documented cut-off concentrations in this study need prospective assessment.