Urine Neutrophil Gelatinase-Associated Lipocalin and Interleukin-18 Predict Acute Kidney Injury after Cardiac Surgery

Abstract

Background. About 30-50% patients develop acute kidney injury (AKI) after cardiac surgery, which is still diagnosed by serum creatinine on clinic. However, the increase of serum creatinine is insensitive and delayed. The aim of this study is to test the hypothesis that neutrophil gelatinase-associated lipocalin (NGAL) and interleukin-18 (IL-18) are early biomarkers for AKI in patients after cardiac surgery. Methods. Thirty-three cases undergoing cardiac surgery were classified into an AKI group and non-AKI group, according to the AKI definition (> 26.5 μmol/L increase of serum creatinine, more than or equal to 50% increase of serum creatinine within 48 h, or a reduction in urine output < 0.5 mL/Kg per hour for more than six hours). The concentrations of serum NGAL, urine NGAL, and urine IL-18 at different time-points were measured. Results. Nine cases (27.27%) developed postoperative AKI, but diagnosis with serum creatinine was 12-48 h postoperation. The concentrations of serum NGAL were not significantly increased postoperation. The concentrations of urine NGAL and IL-18 were significantly increased in the AKI group, which reached the peak at 2-4 h postoperation, and a more significant difference could be seen after correction for urine creatinine. The concentrations of urine NGAL and IL-18 2 h postoperation, either corrected for urine creatinine or not, showed good sensitivity and specificity. Increased levels of urine NGAL and IL-18 2 h postoperation were significantly correlated with increased level of serum creatinine 12 h postoperation. Logistic regression analysis showed that urine NGAL corrected for urine creatinine 2 h postoperation and urine IL-18 2 h postoperation emerged as powerful independent predictors of AKI after cardiac surgery. Conclusions. The concentrations of urine NGAL and IL-18 could be useful biomarkers for AKI in patients after cardiac surgery, especially after correction for urine creatinine.

Neutrophil Gelatinase-Associated Lipocalin and Acute Kidney Injury after Cardiac Surgery

“…However, if so, patients without AKI who receive furosemide may have a marked diuresis, diluting urinary NGAL, whereas patients with evolving AKI may have a blunted response with less urinary dilution, thus enhancing the apparent discriminant ability of urinary NGAL for AKI. Although adjusting NGAL values for urinary creatinine may have been instructive in this regard, urinary creatinine was not measured, and several previous authors have reported limited incremental benefit in doing so (8,11). Additionally, data on perioperative diuretic administration or urine Figure 1.…”

“…Early detection of injury is desirable to facilitate early intervention aimed at limiting associated morbidity and mortality. Neutrophil Gelatinase-Associated Lipocalin (NGAL) is rapidly released by renal tubules in response to injury, and an acute rise in urinary NGAL has been reported to accurately identify evolving AKI in both pediatric and adult populations within 2 to 8 hours of cardiac surgery (5)(6)(7)(8)(9). However, other studies have found urinary NGAL to have only modest discriminant ability for AKI after cardiac surgery (3,10).…”

Tubular proteinuria in acute kidney injury: a critical evaluation of current status and future promise

“…84,112 In adults undergoing percutaneous coronary intervention or cardiopulmonary bypass surgery, the AUCs have ranged widely from 0.61 to 0.96. 76,82,83,90,97,123 In a heterogeneous population of critically ill children, urine NGAL was predictive of subsequent AKI with an AUC of 0.78. 127 In general, the predictive value of urine NGAL appears to be enhanced in children in comparison with adults, with five recent studies reporting AUCs of 0.78 -1.00.…”

“…75,83,90,114,116,117,124 The AUCs have ranged from 0.54 to 0.90. In the setting of cardiac surgery, three studies reported very good to excellent AUCs in the 0.75 -0.90 range 83,90,117 whereas one study reported poor performance with an AUC of 0.55.…”

Proteomic Biomarkers for the Early Detection of Acute Kidney Injury

“…Mass spectrometry combined with chromatographic separation techniques has advanced exceptionally in recent years and has become a valuable tool for profiling of human proteomes and a systematic search of protein and peptide markers indicative for various renal and non-renal diseases without the need for a hypothesis-driven propagation process [54,19,1,93].…”