Neutrophil Gelatinase-Associated Lipocalin in the Prediction of Contrast-induced Nephropathy: A Systemic Review and Meta-analysis.

Objective: The aim of this study was to investigate the predictive value of neutrophil gelatinase-associated lipocalin (NGAL) in the early diagnosis of contrast-induced nephropathy (CIN). Methods: We searched MEDLINE and Embase until December 2014 for articles evaluating the diagnostic accuracy of plasma/serum and urinary NGAL levels to predict CIN. The primary analysis was based on a hierarchical, bivariate, generalized, linear, mixed model. Diagnostic odds ratio (DOR) and sample size-weighted area under the curve for the receiver operating characteristic (AUROC) were calculated. Results: Ten studies involving 1310 patients were analyzed. Overall, the DOR/AUROC for NGAL level to predict CIN was 20.56 [95% confidence interval (CI), 9.67-43.74]/0.87 (95% CI, 0.84-0.90), with sensitivity and specificity of 0.80 (95% CI, 0.74-0.85) and 0.83 (95% CI, 0.73-0.90), respectively. Subgroup analysis showed that the diagnostic performance of the DOR/AUROC of urinary NGAL [29.48 (95% CI, 12.19-71.27)/0.87 (95% CI, 0.84-0.90)] was better than that of plasma/serum NGAL [14.63 (95% CI, 4.51-47.38)/0.85 (95% CI, 0.82-0.88)] (DOR, P = 0.005, and AUROC, P = 0.04, respectively). Conclusions: Plasma/serum and urinary NGAL levels seem to be useful biomarkers in the early prediction of CIN. Moreover, urinary NGAL levels perform better than plasma/serum NGAL.