Novel and conventional serum biomarkers predicting acute kidney injury in adult cardiac surgery-A prospective cohort study
ABSTRACT To compare the value of novel with conventional serum biomarkers in the prediction of acute kidney injury (AKI) in adult cardiac surgical patients according to preoperative renal function.
Single-center, prospective observational study.
One hundred adult cardiac surgical patients.
We measured concentrations of plasma neutrophil gelatinase-associated lipocalin (NGAL), and serum cystatin C, and creatinine and urea at baseline, on arrival in the intensive care unit (ICU) and at 24 hours postoperatively. We assessed such biomarkers in relation to the development of AKI (>50% increase in creatinine from baseline) and to a composite end point (need for renal replacement therapy and in-hospital mortality). We defined an area under the receiver operating characteristic curve of 0.60-0.69 as poor, 0.70-0.79 as fair, 0.80-0.89 as good, and 0.90-1.00 as excellent in terms of predictive value. On arrival in ICU, plasma NGAL and serum cystatin C were of good predictive value, but creatinine and urea were of poor predictive value. After exclusion of patients with preoperative renal impairment (estimated glomerular filtration rate <60 mL/min), the predictive performance for AKI of all renal biomarkers on arrival in ICU remained unchanged except for cystatin C, which was of fair value in such patients. At 24 hours postoperatively, all renal biomarkers were of good predictive value. On arrival in ICU, novel biomarkers were superior to conventional biomarkers (p < 0.05). Plasma NGAL (p = 0.015) and serum cystatin C (p = 0.007) were independent predictors of AKI and of excellent value in the prediction of the composite end point.
Early postoperative measurement of plasma NGAL was of good value in identifying patients who developed AKI after adult cardiac surgery. Plasma NGAL and serum cystatin C were superior to conventional biomarkers in the prediction of AKI and were also of prognostic value in this setting.
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ABSTRACT: Chronic kidney disease (CKD) typically evolves over many years, with a long latent period when the disease is clinically silent and therefore diagnosis, evaluation and treatment is based mainly on biomarkers that assess kidney function. Glomerular filtration rate (GFR) remains the ideal marker of kidney function. Unfortunately measuring GFR is time consuming and therefore GFR is usually estimated from equations that take into account endogenous filtration markers like serum creatinine (SCr) and cystatin C (CysC). Other biomarkers such as albuminuria may precede kidney function decline and have demonstrated to have strong associations with disease progression and outcomes. New potential biomarkers have arisen with the promise of detecting kidney damage prior to the currently used markers. The aim of this review is to discuss the utility of the GFR estimating equations and biomarkers in CKD and the different clinical settings where these should be applied. The CKD-Epidemiology Collaboration equation performs better than the modification of diet in renal disease equation, especially at GFR above 60 mL/min per 1.73 m(2). Equations combining CysC and SCr perform better than the equations using either CysC or SCr alone and are recommended in situations where CKD needs to be confirmed. Combining creatinine, CysC and urine albumin to creatinine ratio improves risk stratification for kidney disease progression and mortality. Kidney injury molecule and neutrophil gelatinase-associated lipocalin are considered reasonable biomarkers in urine and plasma to determine severity and prognosis of CKD.
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ABSTRACT: Introduction/Aims: The Acute Kidney Injury Network classification is based on small increases in serum creatinine (sCr) for stage 1. This study investigated whether changes in the urinary concentration of neutrophil gelatinase-associated lipocalin (uNGAL) could predict small increases in sCr in patients undergoing coronary angiography. Methods: The uNGAL was measured before contrast infusion and 2 and 4 h afterwards. Patients were divided into 2 subgroups: G1 (n = 103), where sCr increased by <0.3 mg/dl, and G2 (n = 22), where sCr increased by ≥0.3 mg/dl 48 h after the angiography. To determine the sensitivity and specificity for the absolute and relative variations of uNGAL, a receiver operating characteristic curve analysis was performed. Results: In G2, the uNGAL concentration increased over baseline values (15.9 vs. 9.2 ng/dl; p < 0.05), and it was also 2-fold higher in G2 versus G1 (15.9 vs. 8.0 ng/dl; p < 0.001). The uNGAL remains an independent predictor of the small increases in sCr, and, for an increase of 50% over baseline levels, it showed 60% sensitivity and 81% specificity. Conclusion: Changes in uNGAL concentration 2 h after the infusion of contrast media showed marginal sensitivity to predict small increases in sCr. © 2015 S. Karger AG, Basel.
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ABSTRACT: Acute kidney injury (AKI) is a common complication that occurs in a broad spectrum of clinical settings. Cardiac surgery-associated AKI continues to be a well-recognized complication of cardiac surgery with high morbidity and mortality. The lack of early biomarkers has for long prevented timely interventions to mitigate the effects of AKI. Serum creatinine is not a timely marker of AKI, so that it cannot be used to set potentially effective therapies to treat AKI in patients during phases when the injury is still potentially reversible. Neutrophil gelatinase–associated lipocalin (NGAL) has been identified as a promising biomarker for early detection of AKI. Several studies have shown that NGAL levels significantly increase in AKI patients 24 to 48 hours before a detectable increase of serum creatinine. Recent studies also suggest that measurements of urinary NGAL levels in patients at risk for cardiac surgery–associated AKI may facilitate its early diagnosis and allow clinicians to implement therapeutic adjustments that have the potential to reverse renal cellular damage and minimize further kidney injury.Acta bio-medica: Atenei Parmensis 12/2014; 85(3):289-94.