Renal arterial resistive index, monocyte chemotactic protein 1 and neutrophil gelatinase-associated lipocalin, for predicting acute kidney injury in critically ill cancer patients

Purpose We evaluated the renal arterial resistive index (RRI), urine monocyte chemotactic protein 1 (uMCP-1), and urine neutrophil gelatinase-associated lipocalin (uNGAL) to predict acute kidney injury (AKI) in critically ill cancer patients. Methods In this prospective study, we included patients without AKI. We compared the area under the curve (AUC) of RRI, uMCP-1, and uNGAL to predict any stage of AKI and stage-3 AKI with the DeLong method, and we established cutoff points with the Youden index. Results We included 64 patients, and 43 (67.2%) developed AKI. The AUC to predict AKI were: 0.714 (95% CI 0.587–0.820) for the RRI, 0.656 (95% CI 0.526–0.770) for uMCP-1, and 0.677 (95% CI 0.549–0.789) for uNGAL. The AUC to predict stage-3 AKI were: 0.740 (95% CI 0.615–0.842) for the RRI, 0.757 (95% CI 0.633–0.855) for uMCP-1, and 0.817 (95% CI 0.701–0.903) for uNGAL, without statistical differences among them. For stage 3 AKI prediction, the sensitivity and specificity were: 56.3% and 87.5% for a RRI > 0.705; 70% and 79.2% for an uMCP-1 > 2169 ng/mL; and 87.5% and 70.8% for a uNGAL > 200 ng/mL. The RRI was significantly correlated to age ( r = 0.280), estimated glomerular filtration rate ( r = − 0.259), mean arterial pressure ( r = − 0.357), and serum lactate ( r = 0.276). Conclusion The RRI, uMCP-1, and uNGAL have a similar ability to predict AKI. The RRI is more specific, while urine biomarkers are more sensitive to predict stage 3 AKI. The RRI correlates with hemodynamic variables. The novel uMCP-1 could be a useful biomarker that needs to be extensively studied.