The Role of Urinary Neutrophil Gelatinase-Associated Lipocalin in Predicting Acute Kidney Dysfunction in Patients With Liver Cirrhosis

Perfusate Neutrophil Gelatinase-Associated Lipocalin, Kidney Injury Molecular-1, Liver-Type Fatty Acid Binding Protein, and Interleukin-18 as Potential Biomarkers to Predict Delayed Graft Function and Long-Term Prognosis in Kidney Transplant Recipients: A Single-Center Retrospective Study

BACKGROUND Delayed graft function (DGF) caused by ischemia-reperfusion injury is a common pathophysiological process that should be monitored by specific biomarkers in addition to serum creatinine. Thus, this single-center retrospective study aimed to investigate the association between levels of neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecular-1 (KIM-1), liver-type fatty acid binding protein (L-FABP), and interleukin-18 (IL-18) in DGF associated with acute kidney injury in kidney transplant recipients (KTRs) and estimated glomerular filtration rate (eGFR) at 3 years post-transplant. MATERIAL AND METHODS A total of 102 KTRs [14(13.7%) of DGF and 88(86.3%) of NON-DGF] were enrolled. DGF was defined as "dialysis is needed within 1 week after kidney transplantation". NGAL, KIM-1, L-FABP, and IL-18 were obtained from perfusate samples of donation-after-cardiac-death (DCD) kidneys, and measured by ELISA. RESULTS Compared to the NON-DGF group, KTRs in the DGF group had a statistically significant increase in levels of NGAL (P<0.001) and KIM-1 (P<0.001). Multiple logistic regression analyses showed that NGAL (OR=1.204, 95% CI 1.057-1.372, P=0.005) and KIM-1 (OR=1.248, CI=1.065-1.463, P=0.006) could be regarded as independent risk factors. The accuracy of NGAL and KIM-1 was 83.3% and 82.1%, respectively, calculated using the area under the receiver operating characteristic curve. Furthermore, the eGFR at 3 years post-transplant had a moderate negative correlation with NGAL (r=-0.208, P=0.036) and KIM-1 (r=-0.260, P=0.008). CONCLUSIONS Our results support those from previous studies showing that perfusate levels of NGAL and KIM-1 are associated with DGF in KTRs and also with reduced eGFR at 3 years post-transplant.

Urine neutrophil gelatinase-associated lipocalin as a biomarker of acute kidney injury and prognosis in decompensated chronic liver disease: A prospective study

BACKGROUND

Acute kidney injury (AKI) heralds deterioration in patients with decompensated chronic liver disease (DCLD). Serum creatinine (sCr), a component of the model for end-stage liver disease-sodium (MELD-Na) prognostic score, has limitations in patients with DCLD. We evaluated the prognostic role of urine neutrophil gelatinase-associated lipocalin (NGAL) in DCLD and its ability to sub-type AKI.

METHODS

Total 147 consecutive patients hospitalized between June 2018 and June 2020 for complications of DCLD were evaluated. Urine NGAL was estimated and demographic, clinical and biochemical parameters recorded at baseline. Participants were followed up till the end of study period or mortality, whichever came earlier. Primary outcomes included all-cause mortality and time to death after index hospitalization. Secondary outcomes included the presence and type of AKI, need for intensive care unit (ICU) stay, length of ICU/hospital stay, in-hospital mortality, development of new-onset/recurrent AKI and recurrent hospitalization after index admission.

RESULTS

Urine NGAL was highest in acute tubular necrosis (ATN), lowest in pre-renal azotemia (PRA) and intermediate in hepatorenal syndrome (HRS-AKI). Urine NGAL (p = 0.0208) was superior to sCr (p = 0.0388) and inferior to fractionated excretion of sodium (FENa) (p = 0.0013) in stratifying AKI. A cut-off of 203.9 ng/mL discriminated between HRS and PRA with sensitivity 77.8% and specificity 68.7%. Urine NGAL correlated with MELD-Na score, need for ICU stay, in-hospital mortality and mortality at three and six months. Two-year survival was significantly lower in patients with urine NGAL > 205 ng/mL. Addition of log-urine-NGAL score did not improve predictive performance of MELD-Na.

CONCLUSION

Urine NGAL could identify AKI sub-types and correlated with short-term clinical outcomes, including mortality.

Novel biomarkers of acute kidney injury in chronic liver disease: Where do we stand after a decade of research?

Acute kidney injury (AKI) is a frequently encountered complication in decompensated chronic liver disease (CLD) with an estimated prevalence of 20%-50% among hospitalized patients. AKI often heralds the onset of a downhill course in the natural history of CLD. Serum creatinine has several limitations as a stand-alone marker of AKI in patients with decompensated CLD. The concept of hepatorenal syndrome, the prototype of AKI in decompensated CLD, has evolved tremendously over recent years. There is emerging evidence of an additional "structural" component in the pathophysiology of hepatorenal syndrome-AKI, which was previously identified as a purely "functional" form of renal impairment. Lacunae in the existent biochemical arsenal for diagnosis and prognosis of AKI have fueled enthusiastic research in the field of novel biomarkers of kidney injury in patients with cirrhosis. The advent of these biomarkers provides a crucial window of opportunity to improve the diagnosis and clinical outcomes of this vulnerable cohort of patients. This review summarizes the dynamic concept of renal dysfunction in CLD and the available literature on the role of novel biomarkers of AKI in assessing renal function, identifying AKI subtypes, and predicting prognosis. There is special emphasis on the renal tubular injury marker, neutrophil gelatinase-associated lipocalin, the most exhaustively studied biomarker of AKI in the CLD population.

Acute kidney injury defined by cystatin C may be superior for predicting the outcomes of liver cirrhosis with acute gastrointestinal bleeding

BACKGROUND & AIMS

Acute kidney injury (AKI) is conventionally evaluated by a dynamic change of serum creatinine (Scr). Cystatin C (CysC) seems to be a more accurate biomarker for assessing kidney function. This retrospective multicenter study aims to evaluate whether AKI re-defined by CysC can predict the in-hospital outcomes of patients with liver cirrhosis and acute gastrointestinal bleeding.

METHODS

Overall, 677 cirrhotic patients with acute gastrointestinal bleeding, in whom both Scr and CysC levels were detected at admissions, were screened. eGFR_Scr, eGFR_CysC, and eGFR_Scr-CysC were calculated. MELD-Na score and AKI were re-evaluated by CysC instead of Scr. Odds ratios (ORs) were calculated in the logistic regression analyses. The receiver operating characteristic (ROC) curve analyses were performed.

RESULTS

Univariate logistic regression analyses demonstrated that baseline Scr and CysC levels, eGFR_Scr, eGFR_CysC, eGFR_Scr-CysC, original MELD-Na score defined by Scr, MELD-Na score re-defined by CysC, and AKI re-defined by CysC, but not conventional AKI defined by Scr, were significantly associated with in-hospital death. ROC analyses showed that baseline CysC level, eGFR_Scr, eGFR_CysC, eGFR_Scr-CysC, original MELD-Na score defined by Scr, and MELD-Na score re-defined by CysC, but not baseline Scr level, could significantly predict the risk of in-hospital death.

CONCLUSIONS

AKI re-defined by CysC may be superior for predicting the in-hospital mortality of cirrhotic patients with acute gastrointestinal bleeding.

Intraoperative systemic biomarkers predict post-liver transplantation acute kidney injury

OBJECTIVE

Liver transplant (LT) is a definitive therapeutic option for patients with chronic liver disease. However, acute kidney injury after LT (post-LT AKI) is a frequent complication that may lead to graft dysfunction and decrease life expectancy. Delay in AKI detection by traditional biomarkers boosted research with new biomarkers for post-LT AKI as neutrophil gelatinase-associated lipocalin (NGAL) and syndecan-1. We aim to evaluate associations of intraoperative systemic NGAL and syndecan-1 levels with post-LT AKI.

METHODS

This is a prospective study conducted in 46 patients selected for LT. Patients were evaluated preoperatively and blood samples were collected intraoperatively: T1 (after induction of anesthesia), T2 (anhepatic phase) and T3 (2 h after reperfusion of the graft).

RESULTS

The mean age was 54 ± 12 years and 60% were male. Post-LT AKI was observed in 24 (52%) patients of which 12% needed dialysis. Serum NGAL and syndecan-1 increased along surgical phases. Mostly, increment values of serum NGAL of T2 to T3 and syndecan-1 at T3 were importantly associated with post-LT AKI. Into a multivariate model with model for end-stage liver disease score, age, gender, warm ischemia, cold ischemia and surgery time, syndecan-1 levels at T3 remains capable to predict post-LT AKI. Serum NGAL had significance only with increment values calculated by the ratio of 'T3/T2'. Finally, serum syndecan-1 at T3 had a better diagnostic performance in receiver operating characteristic curve analysis.

CONCLUSION

Serum syndecan-1 levels in 2 h after reperfusion were most useful in early post-LT AKI diagnosis and may be used to construct new risk groups in this context.

The efficacy of biomarkers in the diagnosis of acute kidney injury secondary to liver cirrhosis

ABSTRACT

This study is to investigate the role of neutrophil gelatinase-associated lipocalin (NGAL), cystatin C (CysC) and creatinine in the diagnosis of acute kidney injury (AKI) secondary to liver cirrhosis.A total of 825 patients (including 540 liver cirrhosis patients and 285 healthy controls) were enrolled. Liver cirrhosis patients were further subdivided into AKI secondary to liver cirrhosis group (AKI group, 210 patients) and simple liver cirrhosis group (LC group, 330 patients). Serum NGAL/urine NGAL (sNGAL/uNGAL), and serum creatinine (sCr) levels as well as estimated glomerular filtration rates were measured. The diagnostic performances of these indicators in AKI secondary to liver cirrhosis were evaluated.The levels of sNGAL, uNGAL, CysC and sCr in the AKI group were significantly higher than those of LC and healthy control groups. However, the eGFR and c-aGFR of AKI group were significantly lower. With the progression of AKI (AKI-S1→AKI-S2→AKI-S3), the levels of sNGAL, uNGAL, CysC and sCr increased gradually, while the levels of c-aGFR and eGFR decreased gradually. The sNGAL, uNGAL and CysC were positively correlated with sCr (r = 0.638, 0.635, and 0.650), but negatively correlated with c-aGFR (r = -0.617, -0.606 and -0.655). However, eGFR had a negative correlation with sCr (r = -0.711), but a positive correlation with c-aGFR (r = 0.736). ROC curve analysis showed that the area under the curve for uNGAL was the largest (0.976), followed by sNGAL (0.967). The diagnostic efficacy of uNGAL and sNGAL in AKI group were 0.907 and 0.870, and the risk degrees were OR = 54.524 and 5.115, respectively.NGAL might perform better than sCr and CysC in the diagnosis of AKI secondary to liver cirrhosis, while uNGAL might be a better indicator than sNGAL in AKI diagnosis.

Clinical Significance of Urinary Neutrophil Gelatinase-associated Lipocalin Levels in Defining the Various Etiologies of Acute Kidney Injury in Liver Cirrhosis Patients

Background/Aims

A diagnosis of hepatorenal syndrome (HRS) is based on a differential evaluation of acute kidney injury (AKI), which may aggravate the clinical course. This study assessed the clinical significance of the urinary neutrophil gelatinase- associated lipocalin (u-NGAL) levels in a differential diagnosis of AKI in patients with liver cirrhosis (LC).

Methods

Patients with LC who developed AKI were enrolled prospectively. Clinically, patients with AKI were classified into prerenal azotemia (PRA), HRS, and acute tubular necrosis (ATN) groups.

Results

Fifty-five patients (male, 74.5%) with LC who exhibited AKI upon admission were enrolled; 28, 9, and 18 patients were included in the PRA, HRS, and ATN groups, respectively. The baseline model for end-stage liver disease (MELD) scores was similar in the subgroups. The median event creatinine level, measured at the time of the AKI diagnosis, was similar in the HRS and ATN subgroups. On the other hand, the median event u-NGAL level differed significantly between the three subgroups (PRA, HRS, and ATN: 37 vs. 134 vs. 2,625 ng/mL, p=0.003). In particular, the median u-NGAL level of the HRS group was clearly different from those of the PRA (p<0.001) and ATN (p<0.001) groups. Multivariable analysis revealed the natural logarithm of the u-NGAL level (hazard ratio [HR] 1.77, p=0.031) and the MELD score (HR 1.17, p=0.027) to be independent prognostic factors for in-hospital mortality in patients with LC and AKI.

Conclusions

The median u-NGAL level differentiated HRS from ATN and served as a clinical indicator of in-hospital mortality for patients with LC and AKI.