Neutrophil gelatinase-associated lipocalin in prediction of mortality in patients with hepatorenal syndrome: a prospective observational study

Reliability of neutrophil gelatinase-associated lipocalin in detecting acute tubular necrosis in decompensated cirrhosis: Systematic review and meta-analysis

BACKGROUND

Acute kidney injury (AKI) in cirrhosis is common. The diagnosis of AKI in cirrhosis patients depends on clinical presentation and laboratory tests like serum creatinine. However, urine biomarkers could also be used to assess the type of AKI and the severity of the disease. We performed a systematic review with meta-analysis to evaluate the association with urine neutrophil gelatinase-associated lipocalin (NGAL) marker in identifying acute tubular necrosis (ATN) in patients with cirrhosis.

AIM

To assess the reliability of urine NGAL in the detection of ATN in patients with cirrhosis.

METHODS

We systematically searched MEDLINE and PubMed using keywords including "urine biomarkers", "NGAL", "kidney dysfunction", and "cirrhosis" to identify relevant studies. Data was screened and extracted. Included studies assessed hospitalized cirrhosis patients with AKI using the urine NGAL biomarker. We synthesized the data using diagnostic odds ratio (DOR), comparative and descriptive analyses, and Cochran Mantel-Haenszel (CMH) statistics to evaluate heterogeneity.

RESULTS

Three thousand seven hundred and one patients with cirrhosis were analyzed from a total of 21 cohort studies. The DOR of 14 of those studies [pooled DOR: 22.150, (95%CI: 17.58-27.89), P < 0.0001] demonstrated a significant association between urine NGAL levels and its identification of ATN. Following stratification by cirrhosis status, heterogeneity was analyzed and showed a significant non-zero correlation between NGAL and AKI (CMH statistic = 702.19, P < 0.0001).

CONCLUSION

In patients with cirrhosis, the use of urine NGAL is a reliable biomarker for detecting ATN and identifying the etiology of AKI.

Dynamic changes and clinical value of lipocalin 2 in liver diseases caused by microbial infections

Lipocalin 2 (LCN2) plays a pivotal role in iron metabolism, particularly in the context of microbial infection resistance (e.g., viruses, bacteria, parasites, etc.). LCN2 combats microbial infection by directly assisting the body in competing with microorganisms for iron, inducing immune cells to secrete various cytokines to enhance systemic immune responses, or recruiting neutrophils to infectious sites. The liver serves as the primary organ for LCN2 secretion during microbial infections. This review encapsulates recent advances in dynamic changes, clinical values, and the effects of LCN2 in infectious liver diseases caused by various microbial microorganisms.

Neutrophil Gelatinase-associated Lipocalin Predicts Short-term Outcomes in Decompensated Cirrhosis With Acute Kidney Injury

Background and aims

Acute kidney injury (AKI) increases mortality in cirrhosis. Early identification of the cause of AKI helps in planning appropriate management. We aimed to find whether neutrophil gelatinase-associated lipocalin (NGAL) can be used to differentiate between different types of AKI in cirrhosis and predict short-term outcomes in patients with decompensated cirrhosis and AKI.

Method

This was a time-bound study in which consecutive hospitalized patients with cirrhosis and AKI were prospectively recruited and managed as per standard care. Acute on chronic liver failure (ACLF) was diagnosed as per the EASL-CLIF Acute-on-Chronic Liver Failure in Cirrhosis (CANONIC) criteria. Urine NGAL was measured by enzyme-linked immunosorbent assay (ELISA) by Epitope Diagnostics Inc. kit (San Diego, USA.) in all patients on admission, and patients were followed up until hospital discharge or death.

Results

A total of 110 consecutive patients (median [range] age: 44 [28-81] years;87.3%were male; ACLF: 71.8%; acute decompensation 28.2%; Model for end-stage liver disease (MELD) 27 [13-46]; Child-Turcotte-Pugh (CTP) 11 [7-15]) with cirrhosis and AKI were recruited. Alcohol was the most common etiology of cirrhosis(64.5%)). Pre-renal azotemia (PRA) was the most common cause of AKI (n = 56). Urine NGAL was significantly elevated in acute tubular necrosis (ATN) (1747 [6-6141] ng/ml than in hepatorenal syndrome (HRS) (379 [33.5-2320] ng/ml; P < 0.0001) and PRA (167 ng/ml [3.34-660]; P < 0.0001). Sixty-four percent patients with ATN, 27.6% patients with HRS, and none with PRA required dialysis. A total of 79.31% patients with HRS and 76% with ATN died. Urine NGAL was significantly higher in patients who required hemodialysis than in those who did not (1733 [243-6141] ng/ml vs 235 [3.34-2320] ng/ml; P < 0.0001). Both urine NGAL (n = 110) and plasma NGAL (n = 90) were significantly higher in patients who died (urine NGAL: -475 [6-6141] ng/ml vs 247 [3.34-2320] ng/ml; P = 0.002;plasma NGAL-950 [94-4859] ng/ml vs 608 [18-3300)]g/ml; P < 0.001). On multivariate analysis, urine NGAL and INR could predict mortality.

Conclusion

NGAL can differentiate between different types of AKI in cirrhosis and predict the need for hemodialysis and mortality in decompensated cirrhosis with AKI.

A novel score of IL-13 and age predicts 90-day mortality in severe alcohol-associated hepatitis: A multicenter plasma biomarker analysis

BACKGROUND

Severe alcoholic hepatitis (AH) has a high short-term mortality rate. The MELD assesses disease severity and mortality; however, it is not specific for AH. We screened plasma samples from patients with severe AH for biomarkers of multiple pathological processes and identified predictors of short-term mortality.

METHODS

Plasma was collected at baseline from 85 patients with severe AH (MELD≥20, Maddrey's discriminant function≥32) enrolled in the Defeat Alcoholic Steatohepatitis clinical trial (investigating IL-1 receptor antagonist+pentoxifylline+zinc vs. methylprednisolone+placebo). Samples were analyzed for 43 biomarkers and the markers' association with 28- and 90-day mortalities was assessed.

RESULTS

Thirty-one (36.5%) patients died during the 90-day follow-up with similar ratios in the treatment groups. Eight biomarkers showed an association with mortality. IL-6, IL-22, interferon-α2, soluble TNF receptor 1, lipocalin-2, and α-fetoprotein levels were associated with 28-day mortality, while IL-6, IL-13, and endotoxin levels with 90-day mortality. In multivariable Cox regression, encephalopathy, lipocalin-2, and α-fetoprotein levels were independent predictors of 28-day mortality, and IL-6, IL-13, international normalized ratio levels, and age were independent predictors of 90-day mortality. The combination of IL-13 and age had superior performance in predicting 90-day mortality compared with MELD in the total cohort and the individual treatment groups.

CONCLUSIONS

We identified predictors of short-term mortality in a cohort exclusively involving patients with severe AH. We created a composite score of IL-13 and age that predicts 90-day mortality regardless of the treatment type with a performance superior to MELD in severe AH.

Recent advances in pathophysiology, diagnosis and management of hepatorenal syndrome: A review

Hepatorenal syndrome with acute kidney injury (HRS-AKI) is a form of rapidly progressive kidney dysfunction in patients with decompensated cirrhosis and/or acute severe liver injury such as acute liver failure. Current data suggest that HRS-AKI occurs secondary to circulatory dysfunction characterized by marked splanchnic vasodilation, leading to reduction of effective arterial blood volume and glomerular filtration rate. Thus, volume expansion and splanchnic vasoconstriction constitute the mainstay of medical therapy. However, a significant proportion of patients do not respond to medical management. These patients often require renal replacement therapy and may be eligible for liver or combined liver-kidney transplantation. Although there have been advances in the management of patients with HRS-AKI including novel biomarkers and medications, better-calibrated studies, more widely available biomarkers, and improved prognostic models are sorely needed to further improve diagnosis and treatment of HRS-AKI.

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.

Novel Biomarkers of AKI in Cirrhosis

Acute kidney injury (AKI) is a frequent complication in patients with cirrhosis that is associated with poor outcomes and decreased survival. The definition of AKI in cirrhosis is currently based on changes of serum creatinine levels with respect to baseline values. Differential diagnosis of the causes of AKI is of major relevance, considering that some causes of AKI, such as hepatorenal syndrome, have specific treatment options and different prognosis. Prediction of kidney function recovery and patients' survival is also crucial in this patient population to guide clinical decisions. AKI biomarkers in cirrhosis have emerged as a promising tool for differential diagnosis and prognosis in this situation. There are consistent data showing that some urine biomarkers, particularly neutrophil gelatinase-associated lipocalin, may be useful in daily clinical practice for the differential diagnosis of the cause of AKI in cirrhosis. AKI biomarkers may constitute a useful tool for use in differential diagnosis, prognosis of renal function, and survival in patients with cirrhosis. This review focuses on the current state of knowledge and future perspective of novel biomarkers of AKI in cirrhosis.

Urinary neutrophil gelatinase-associated lipocalin: Acute kidney injury in liver cirrhosis

Acute kidney injury (AKI) in liver cirrhosis is associated with poor clinical outcomes including an increased long and short-term mortality. The common type of AKI observed in patients with cirrhosis are prerenal AKI (PRA), hepatorenal syndrome (HRS) and acute tubular necrosis (ATN). Despite the growing knowledge and uniform definition for the diagnosis of AKI, there are several challenges including, early diagnosis and management. Precisely differentiating the type of AKI is critical, as therapies differ significantly. In this review, we summarize AKI in liver cirrhosis, their definition, pathophysiology and deficiencies of using the existing biomarker, serum creatinine. We outline the current clinical evidence on the novel biomarker urinary neutrophil gelatinase-associated lipocalin (uNGAL) and its potential role as a biomarker in the early detection, differentiation and prognostication of AKI. This review also briefly talks about other forthcoming biomarkers which hold promise in the management of AKI in liver cirrhosis.

Improved prediction of mortality by combinations of inflammatory markers and standard clinical scores in patients with acute-on-chronic liver failure and acute decompensation

BACKGROUND AND AIM

Acute-on-chronic liver failure (ACLF) is a sinister prognosis, and there is a need for accurate biomarkers and scoring systems to better characterize ACLF patients and predict prognosis. Systemic inflammation and renal failure are hallmarks in ACLF disease development and progression. We hypothesized that the combination of specific inflammatory markers in combination with clinical scores are better predictors of survival than the originally developed CLIF-C acute decompensation (AD) and CLIF-C ACLF scores.

METHODS

We reevaluated all previously measured inflammatory markers in 522 patients from the CANONIC study, 342 without and 180 with ACLF. We used the Harrell's C-index to determine the best marker alone or in combination with the original scores and calculated new scores for prediction of mortality in the original CANONIC cohort.

RESULTS

The best markers to predict 90-day mortality in patients without ACLF were the plasma macrophage activation markers soluble (s)CD163 and mannose receptor (sMR). Urinary neutrophil gelatinase associated lipocalin (UNGAL) and sCD163 were predictors for 28-day mortality in patients with ACLF. The newly developed CLIF-C AD + sMR score in patients without ACLF improved 90-day mortality prediction compared with the original CLIF-C AD score (C-index 0.82 [0.78-0.86] vs 0.74 [0.70-0.78, P = 0.004]). Further, the new CLIF-C ACLF + sCD163 + UNGAL improved the original CLIF-C ACLF score for 28-day mortality (0.85 [0.79-0.91] vs 0.75 [0.70-0.80], P = 0.039).

CONCLUSIONS

The capability of these inflammatory markers to improve the original prognostic scores in cirrhosis patients without and with ACLF points to a key role of macrophage activation and inflammation in the development and progression of AD and ACLF.

Urinary neutrophil gelatinase-associated lipocalin determines short-term mortality and type of acute kidney injury in cirrhosis

Background and Aim

Acute kidney injury increases mortality in cirrhotic patients by four fold. This study aimed to determine the usefulness of urinary neutrophil gelatinase-associated lipocalin (uNGAL) for differential diagnosis for acute kidney injury and for predicting short-term mortality in cirrhotic patients.

Methods

We enrolled 94 patients of decompensated cirrhosis. uNGAL was measured upon hospital admission in all patients. Patients with urinary tract infection and anuria were excluded. Patients were followed for 30 days or until death.

Results

Ten (9%) patients had normal kidney function, 9 (11.37%) stable chronic kidney disease, 32 (29.50%) prerenal azotemia, 33 (36.37%) hepatorenal syndrome (HRS), and 10 (13.64%) intrinsic acute kidney injury (iAKI). Prerenal azotemia had lower median uNGAL values compared to HRS and iAKI (95.50 vs 465.00 vs 1217.50, P < 0.001). uNGAL levels were significantly higher in patients who died within 30 days (717.17 ± 494.26 vs 331.65 ± 313.65 ng/mL, P -0.0017). On univariate analysis, serum creatinine (sCr), uNGAL, Model for End-Stage Liver Disease (MELD) score on admission, and length of stay were significant, and on multivariate analysis, uNGAL and hepatic encephalopathy (HE) were significant in predicting mortality.

Conclusions

uNGAL at baseline serves as an early marker in differentiating HRS, prerenal AKI, and iAKI in cirrhotic patients, where sCr values are not useful. Patients with higher uNGAL levels had higher transplant-free mortality at 30 days.

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.

Fluid Biomarkers for Predicting the Prognosis of Liver Cirrhosis

Liver cirrhosis is the terminal stage of most chronic liver conditions, with a high risk of mortality. Careful evaluation of the prognosis of cirrhotic patients and providing precise management are crucial to reduce the risk of mortality. Although the liver biopsy and hepatic venous pressure gradient (HVPG) can efficiently evaluate the prognosis of cirrhotic patients, their application is limited due to the invasion procedures. Child-Pugh score and the model for end-stage liver disease (MELD) score had been widely used in the assessment of cirrhotic prognosis, but the defects of subjective variable application in Child-Pugh score and unsuitability to all phases of liver cirrhosis in MELD score limit their prognostic values. In recent years, continuous efforts have been made to investigate the prognostic value of body fluid biomarkers for cirrhotic patients, and promising results have been reported. Since the collection of fluid specimens is easy, noninvasive, and repeatable, fluid biomarkers can be ideal indicators to predict the prognosis of cirrhosis. Here, we reviewed noninvasive fluid biomarkers in different prognostic functions, including the prediction of survival and complication development.

A decision support system for the prediction of mortality in patients with acute kidney injury admitted in intensive care unit

Intensive care unit (ICU) is a very special unit of a hospital, where healthcare professionals provide treatment and, later, close follow-up to the patients. It is crucial to estimate mortality in ICU patients from many viewpoints. The purpose of this study is to classify the status of patients with acute kidney injury (AKI) in ICU as early mortality, late mortality, and survival by the application of Classification and Regression Trees (CART) algorithm to the patients' attributes such as blood urea nitrogen, creatinine, serum and urine neutrophil gelatinase-associated lipocalin (NGAL), alkaline phosphatase, lactate dehydrogenase (LDH), gamma-glutamyl transferase, laboratory electrolytes, blood gas, mean arterial pressure, central venous pressure and demographic details of patients. This study was conducted 50 patients with AKI who were followed up in the ICU. The study also aims to determine the significance of relationship between the attributes used in the prediction of mortality in CART and patients' status by employing the Kruskal-Wallis H test. The classification accuracy, sensitivity, and specificity of CART for the tested attributes for the prediction of early mortality, late mortality, and survival of patients were 90.00%, 83.33%, and 91.67%, respectively. The values of both urine NGAL and LDH on day 7 showed a considerable difference according to the patients' status after being examined by the Kruskal-Wallis H test.

Serum Neutrophil Gelatinase-Associated Lipocalin (NGAL) in HCV-Positive Egyptian Patients Treated with Sofosbuvir

Background

Direct-acting antivirals (DAAs) made a drastic change in the management of HCV infection. Sofosbuvir is one of the highly potent DAAs, eliminated mainly through the kidney. But concerns about renal safety during treatment may limit its use. Neutrophil gelatinase-associated lipocalin (NGAL) has been proven as a predictor of renal tubular injury. Hence, the aim of this work was to assess serum neutrophil gelatinase-associated lipocalin (NGAL) in HCV-positive patients before and after treatment with the sofosbuvir-based antiviral regimen.

Methods

This prospective study included 87 Egyptian patients with chronic HCV infection treated with sofosbuvir plus daclatasvir with or without ribavirin for 12 weeks. Serum NGAL was measured before and at the end of treatment (EOT). Analysis of NGAL and estimated glomerular filtration rate (eGFR) evolution was done.

Results

Our results showed a statistically significant decrease in serum NGAL (P=0.02) with a nonsignificant reduction in eGFR (P=0.02) with a nonsignificant reduction in eGFR (P=0.02) with a nonsignificant reduction in eGFR (P=0.02) with a nonsignificant reduction in eGFR (P=0.02) with a nonsignificant reduction in eGFR (.

Conclusions

Sofosbuvir appears to have no nephrotoxic effects and is safe to treat patients with chronic HCV infection.

Utility of Urinary Neutrophil gelatinase associated lipocalin (NGAL) in decompensated cirrhosis

Background and Aims:

Renal failure occurring in the setting of cirrhosis increases mortality by more than threefold. Serum creatinine, the conventional marker for renal dysfunction has inherent limitations in identifying and categorizing renal dysfunction in patients with chronic liver disease (CLD). Neutrophil gelatinase associated lipocalin (NGAL) is a novel biomarker which gets upregulated as early as 2-6 hours following the insult to renal tubules. In this study, we aim to check the utility of uNGAL to identify the different phenotypes of renal dysfunction in patients with CLD. We also intend to assess the utility of NGAL to predict 90-day transplant-free survival in patients with CLD.

Methods:

A total number of 120 adult patients, with cirrhosis of liver were recruited. Those with pre-existing renal parenchymal disease, receiving nephrotoxic medications, spontaneous bacterial peritonitis, septic shock, proteinuria, hematuria, urinary tract infection and anuria were excluded. Urine samples for NGAL was measured at admission and at 48 hours thereafter. Patients were followed up for 90 days post admission.

Results:

Among the study population, 16 patients (13.3%) had normal kidney function, 43 (35.8%) had prerenal azotemia and 54 (45%) had Hepatorenal Syndrome (HRS - AKI) and 7 (5.8%) had acute tubular necrosis (ATN). Urinary NGAL (uNGAL) levels were considerably lower in patients with normal kidney function and prerenal azotemia. An uNGAL level of 124 ng/ml on admission could distinguish severe forms of renal injury, with a sensitivity of 86% and specificity of 84%. The non survivors had higher uNGAL levels at admission [209.6 ng/ml (118.7-376.8) vs. 123 (33.6-344.3); P = 0.013].The receiver operated curves for uNGAL and serum creatinine at admission did not show any significant difference for predicting 90 day mortality (AUC for uNGAL: 0.632 vs 0.580 for serum creatinine; difference in AUC 0.053, P value 0.17).

Conclusion:

uNGAL levels are elevated in patients with HRS-AKI and ATN. A higher uNGAL level at admission was suggestive of severe renal dysfunction. An elevated uNGAL on admission is associated with inferior survival. However, uNGAL is not superior to serum creatinine in predicting 90-day mortality.

Therapeutic Targeting of Neutrophil Granulocytes in Inflammatory Liver Disease

Neutrophil granulocytes are the most numerous type of leukocyte in humans bearing an enormous, yet largely unexplored therapeutic potential. Scientists have very recently increased their efforts to study and understand these cells which contribute to various types of inflammatory diseases and cancer. The mechanisms that regulate neutrophil recruitment to inflamed tissues and neutrophil cytotoxic activities against host tissues and pathogens require more attention. The reactive oxygen species (ROS) are a popular source of cellular stress and organ injury, and are critically expressed by neutrophils. By combating pathogens using molecular combat factors such as neutrophil extracellular traps (NETs), these are immobilized and killed i.e., by ROS. NETs and ROS are essential for the immune defense, but upon excessive activation, may also harm healthy tissue. Thus, exploring new routes for modulating their migration and activation is highly desired for creating novel anti-inflammatory treatment options. Leukocyte transmigration represents a key process for inflammatory cell infiltration to injury sites. In this review, we briefly summarize the differentiation and roles of neutrophils, with a spotlight on intravital imaging. We further discuss the potential of nanomedicines, i.e., selectin mimetics to target cell migration and influence liver disease outcome in animal models. Novel perspectives further arise from formulations of the wide array of options of small non-coding RNA such as small interfering RNA (siRNA) and micro-RNA (miR) which exhibit enzymatic functions: while siRNA binds and degrades a single mRNA based on full complementarity of binding, miR can up and down-regulate multiple targets in gene transcription and translation, mediated by partial complementarity of binding. Notably, miR is known to regulate at least 60% of the protein-coding genes and thus includes a potent strategy for a large number of targets in neutrophils. Nanomedicines can combine properties of different drugs in a single formulation, i.e., combining surface functionalization with ligands and drug delivery. Inevitably, nanomedicines accumulate in other phagocytes, a fact that should be controlled for every novel formulation to restrain activation of macrophages or modifications of the immunological synapse. Controlled drug release enabled by nanotechnological delivery systems may advance the options of modulating neutrophil activation and migration.

Biomarkers for acute kidney injury in decompensated cirrhosis: A prospective study

AIM

Acute kidney injury (AKI) is a frequent complication in cirrhotic patients. As serum creatinine is a poor marker of renal function in this population, we aimed to study the utility of several biomarkers in this context.

METHODS

A prospective study was conducted in hospitalized patients with decompensated cirrhosis. Serum creatinine (SCr), Cystatin C (CystC), NGAL and urinary NGAL, KIM-1, protein, albumin and sodium were measured on three separate occasions. Renal resistive index (RRI) was obtained. We analyzed the value of these biomarkers to determine the presence of AKI, its aetiology [prerenal, acute tubular necrosis (ATN), or hepatorenal (HRS)], its severity and a composite clinical outcome at 30 days (death, dialysis and intensive care admission).

RESULTS

We included 105 patients, of which 55 had AKI. SCr, CystC, NGAL (plasma and urinary), urinary sodium and RRI at inclusion were independently associated with the presence of AKI. SCr, CystC and plasma NGAL were able to predict the subsequent development of AKI. Pre-renal state showed lower levels of SCr, NGAL (plasma and urinary) and RRI. ATN patients had high levels of NGAL (plasma and urinary) as well as urinary protein and sodium. HRS patients presented an intermediate pattern. All biomarkers paralleled the severity of AKI. SCr, CystC and plasma NGAL predicted the development of the composite clinical outcome with the same performance as the MELD score.

CONCLUSIONS

In patients with decompensated cirrhosis, early measurement of renal biomarkers provides valuable information on AKI aetiology. It could also improve AKI diagnosis and prognosis.

Role of altered immune cells in liver diseases: a review

Immune cells play an important role in controlling liver tumorigenesis, viral hepatitis, liver fibrosis and contribute to pathogenesis of liver inflammation and injury. Accumulating evidence suggests the effectiveness of natural killer (NK) cells and Kupffer cells (KCs) against viral hepatitis, hepatocellular damage, liver fibrosis, and carcinogenesis. Activation of natural killer cells provides a novel therapeutic strategy to cure liver related diseases. This review discusses the emerging roles of immune cells in liver disorders and it will provide baseline data to scientists to design better therapies for treatment.

Serum adrenomedullin and urinary thromboxane B2 help early categorizing of acute kidney injury in decompensated cirrhotic patients: A prospective cohort study

AIMS

Increases in the systemic vasodilator adrenomedullin and the renal vasoconstrictors thromboxane A₂ in cirrhotic patients are pathogenic factors for the development of functional acute kidney injury (AKI), including pre-renal azotemia (PRA) and hepatorenal syndrome (HRS), which is associated with high mortality. This study aims to find biomarkers that can diagnose HRS at an early stage, to enable treatment as soon as possible.

METHODS

Acute decompensated cirrhotic patients who had been admitted to hospital were enrolled in this prospective cohort study. Blood and urinary samples were collected immediately after admission. In addition to initially categorizing AKI cases into PRA, acute tubular necrosis (ATN), and HRS groups, their final diagnosis was adjudicated by a nephrologist and a hepatologist who checked the corrected and misclassification rates for significant biomarkers.

RESULTS

The cut-off values for serum adrenomedullin and urinary thromboxane B₂ (TXB₂ ), when used as predictors for functional AKI (adrenomedullin >283 pg/mL, urinary TXB₂ >978 [pg/mg urinary creatinine]), for HRS (adrenomedullin >428, urinary TXB₂  >1604), and for good terlipressin plus albumin treatment responders (adrenomedullin >490, urinary TXB₂  >1863), were observed. Patients with HRS who could be treated, due to high mortality, had significantly higher serum adrenomedullin and urinary TXB₂ levels compared to HRS patients receiving standard treatment. In addition to predicting 60-day mortality, a combination of these two markers further increased diagnostic accuracy for HRS among functional AKI.

CONCLUSIONS

Prompt diagnosis of HRS by differentiating it from PRA and ATN can be achieved by using serum adrenomedullin and urinary TXB₂ in acute decompensated cirrhotic patients. In combination with severe clinical courses, these two markers are useful to select HRS patients who cannot be treated.

Urine Interleukin 18 and Lipocalin 2 Are Biomarkers of Acute Tubular Necrosis in Patients With Cirrhosis: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Acute kidney injury (AKI) is a common complication in patients with cirrhosis that increases mortality. The most common causes of AKI in these patients are prerenal azotemia, acute tubular necrosis (ATN), and hepatorenal syndrome; it is important to determine the etiology of AKI to select the proper treatment and predict patient outcome. Urine biomarkers could be used to differentiate between patients with ATN and functional causes of AKI. We performed a systematic review and meta-analysis of published studies to determine whether urine levels of interleukin (IL)18 and lipocalin 2 or neutrophil gelatinase-associated lipocalin (NGAL) are associated with the development of ATN in patients with cirrhosis.

METHODS

We searched MEDLINE, Scopus, ISI Web of Knowledge, and conference abstracts through December 31, 2015, for studies that assessed urine biomarkers for detection of acute kidney injury in patients with cirrhosis or reported an association between urine biomarkers and all-cause mortality in these patients. We included only biomarkers assessed in 3 or more independent studies, searching for terms that included urine biomarkers, cirrhosis, NGAL, and IL18. We calculated the pooled sensitivities and specificities for detection and calculated the area under the receiver operating characteristic curve (AUC) values using a bivariate logistic mixed-effects model. We used the χ² test to assess heterogeneity among studies.

RESULTS

We analyzed data from 8 prospective studies, comprising 1129 patients with cirrhosis. We found urine levels of the markers discriminated between patients with ATN and other types of kidney impairments, with AUC values of 0.88 for IL18 (95% confidence interval [CI], 0.79-0.97) and 0.89 for NGAL (95% CI, 0.84-0.94). Urine levels of IL18 identified patients who would die in the hospital or within 90 days (short-term mortality) with an AUC value of 0.76 (95% CI, 0.68-0.85); NGAL identified these patients with the same AUC (0.76; 95% CI, 0.71-0.82).

CONCLUSIONS

In a systematic review and meta-analysis, we found that urine levels of IL18 and NGAL from patients with cirrhosis discriminate between those with ATN and other types of kidney impairments, with AUC values of 0.88 and 0.89, respectively. Urine levels of IL18 and NGAL identified patients with short-term mortality with an AUC value of 0.76. These biomarkers might be used to determine prognosis and select treatments for patients with cirrhosis.

Renal dysfunction in cirrhosis: acute kidney injury and the hepatorenal syndrome

Renal dysfunction is a common complication of liver cirrhosis and of utmost clinical and prognostic relevance. Patients with cirrhosis are more prone to developing acute kidney injury (AKI) than the non-cirrhotic population. Pre-renal AKI, the hepatorenal syndrome type of AKI (HRS-AKI, formerly known as 'type 1') and acute tubular necrosis represent the most common causes of AKI in cirrhosis. Correct differentiation is imperative, as treatment differs substantially. While pre-renal AKI usually responds well to plasma volume expansion, HRS-AKI and ATN require different specific approaches and are associated with substantial mortality. Several paradigms, such as the threshold of 2.5 mg/dL for diagnosis of HRS-AKI, have recently been abolished and novel urinary biomarkers are being investigated in order to facilitate early and correct diagnosis and treatment of HRS-AKI and other forms of AKI in patients with cirrhosis. This review summarizes the current diagnostic criteria, as well as pathophysiologic and therapeutic concepts for AKI and HRS-AKI in cirrhosis.

Neutrophil gelatinase-associated lipocalin and cystatin C in cirrhosis and portal hypertension: Relations to organ extraction and dysfunction

BACKGROUND AND AIMS

Early detection of renal dysfunction in cirrhosis is important, and several renal biomarkers have been put forward. Neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C are markers of renal dysfunction, but relations to splanchnic and systemic hemodynamics and kinetics are sparsely studied in cirrhosis. In patients with cirrhosis and portal hypertension, we studied plasma levels and renal, hepatic, and peripheral extraction of NGAL and cystatin C and relations to patients characteristics, liver dysfunction, and hemodynamics.

METHODS

Forty-five cirrhotic patients (Child class A/B/C:15/15/15) and 15 controls were evaluated with a full clinical, biochemical, and hemodynamic assessment. Urine and regional plasma concentrations of NGAL and cystatin C were measured.

RESULTS

There was no significant difference in circulating or hepatic NGAL or cystatin C between all patients and controls but a trend towards increased levels with increasing Child class. In addition, there was a significant renal but no hepatic or systemic extraction of both NGAL and cystatin C (P < 0.001). Plasma NGAL correlated with glomerular filtration rate (r = -0.56, P < 0.0001), and hepatic venous pressure gradient (r = 0.34,P = 0.02) and urinary NGAL correlated with heart rate (r = 0.58, P= 0.007), blood pressure (r = -0.46, P < 0.05), cardiac output (r = 0.45, P < 0.05), and systemic vascular resistance (SVR) (r = -0.48, p < 0.05). Plasma cystatin C correlated with hepatic venous pressure gradient (r = 0.45, P < 0.005), blood pressure (-0.40, P < 0.01), and glomerular filtration rate (r = 0.98, P < 0.000).

CONCLUSIONS

Extractions of NGAL and cystatin C levels seem largely unaffected by the severity of liver disease in cirrhosis with a renal extraction. These biomarkers therefore have the potential of being both valuable in diagnosing renal failure and reflecting the degree of portal hypertension and systemic haemodynamic changes.

Hepatorenal syndrome in cirrhosis: diagnostic, pathophysiological, and therapeutic aspects

Renal failure is a common and serious complication in cirrhosis and represents a wide spectrum of etiologies. The hepatorenal syndrome (HRS) represents a distinct type of renal failure, only seen in cirrhotic patients with ascites. The diagnostic criteria, knowledge in the pathophysiology of renal failure and HRS, and treatment hereof, have evolved tremendously during the last decades, and it is the aim of this review to summarize these discoveries. Areas covered: The focus will primarily be on treatment and prevention of renal failure and HRS, but areas concerning definition, diagnosis, including biomarkers, and pathophysiology, will also be covered through a comprehensive, critical reading of the latest literature, encompassing the most recent, updated, international guidelines, reviews and high-impact original literature. Expert commentary: The advances made in the understanding of the pathophysiology of HRS and other complications of cirrhosis within the recent decades, have provided the basis for improved diagnostic criteria and the development of treatments that have substantially increased survival rates in cirrhotic patients suffering from these conditions. Focus should, in the nearest future, be on continuing this positive development, thus further improving prognosis for cirrhotic patients with HRS.

Urinary NGAL-Positive Acute Kidney Injury and Poor Long-term Outcomes in Hospitalized Patients

Introduction

Neutrophil gelatinase−associated lipocalin (NGAL) is a widely studied biomarker of renal tubular injury. Urinary NGAL (uNGAL) during acute kidney injury (AKI) predicts short-term adverse outcomes. However, the long-term predictive value is unknown.

Methods

We performed a prospective observational study of 145 patients with hospital-acquired AKI according to Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease (RIFLE) criteria and analyzed the long-term predictive value of uNGAL at the time of AKI. We defined a composite outcome of all-cause mortality and the development of end-stage renal disease (ESRD).

Results

In all, 61 AKI patients died and 22 developed ESRD within 6 months. The uNGAL levels were significantly higher in patients with poor long-term outcomes. uNGAL levels ≥362 μg/l (highest quartile) and uNGAL levels between 95 and 362 μg/l (third quartile) were associated with hazard ratios of 3.7 (95% confidence interval, 2.1–6.5) and 1.9 (1.1–3.5), respectively, compared with uNGAL levels <95 μg/l (lower quartiles). After 6 months, 67% and 43% of patients within the highest and third uNGAL quartile, respectively, had either progressed to ESRD or died, compared to only 21% of patients with uNGAL in the lower 2 quartiles (P < 0.001). In multivariable Cox regression analyses accounting for conventional predictors, uNGAL was the strongest independent predictor of adverse long-term outcomes. The association of uNGAL levels and poor long-term outcomes remained significant in the subgroup of 107 AKI survivors discharged without requiring dialysis (P = 0.002).

Discussion

These data indicate that elevated uNGAL levels at AKI diagnosis predict poor long-term outcomes.

Is neutrophil gelatinase associated lipocalin useful in hepatitis C virus infection?

AIM: To evaluate neutrophil gelatinase associated lipocalin (NGAL) in patients infected by hepatitis C virus (HCV) before and during treatment with directly acting antivirals (DAAs).

METHODS: NGAL was measured in a group of patients with chronic HCV infection ranked, at baseline, by age, gender, anti-hypertensive therapy, HCV viral load, liver fibrosis stage and, either at baseline or after 1 year, estimated glomerular filtration rate (eGFR). Then, NGAL and eGFR evolutions were monitored in a subgroup of patients who started antiviral therapy with DAAs. Differences of median NGAL levels were evaluated through Wilcoxon-Mann-Whitney test for non-parametric data. Differences in dichotomous variables were evaluated through χ² test. At baseline, a univariate regression analysis was conducted to verify if NGAL values correlated with other quantitative variables [age, fibrosis four (FIB-4), AST to platelet ratio index (APRI), and eGFR].

RESULTS: Overall, 48 patients were enrolled, 8 of them starting HCV treatment. At baseline, statistically significant differences were found in median NGAL values only between patients with eGFR < 60 mL/min vs patients with eGFR ≥ 90 mL/min. Differences in NGAL were not significant among patients ranked by HCV viral load, FIB-4 score and APRI, when patients with NGAL > 118.11 ng/dL were compared with those of NGAL ≤ 118.11 ng/dL, not statistically significant differences were present for age, gender, chronic kidney disease classification and liver fibrosis (P > 0.05). Linear correlation was found between NGAL and both age (P = 0.0475) and eGFR (P = 0.0282) values. Not statistically significant predictions of NGAL at baseline were demonstrated for eGFR evolution 1 year later. Interestingly, in the 8 patients treated with DAAs, median NGAL significantly increased at week 12 compared to baseline (P = 0.0239).

CONCLUSION: Our results suggest that NGAL should be further evaluated as an adjunct marker of kidney function in these patients.

Urine neutrophil gelatinase-associated lipocalin: a diagnostic and prognostic marker for acute kidney injury (AKI) in hospitalized cirrhotic patients with AKI-prone conditions

BACKGROUND

Acute kidney injury (AKI) is known to increase mortality in hospitalized cirrhotic patients; therefore early identification is utmost significance. There are only a few studies evaluating the cut-off level of urine neutrophil gelatinase-associated lipocalin (uNGAL) for diagnosing AKI and its prognostic value in cirrhotic patients. We aimed to determine the accuracy of uNGAL as a biomarker for early identification of AKI and to determine the cut-off level of uNGAL for diagnosing AKI in hospitalized cirrhotic patients; and (2) to explore the association of 30-day liver-related mortality with uNGAL level.

METHODS AND MATERIAL

We prospectively enrolled cirrhotic patients admitted at the King Chulalongkorn Memorial Hospital during May 1, 2011 to Dec 31, 2013. UNGAL levels were measured within 24 h after admission. Clinical and laboratory data were obtained. Patients were followed up to 30 days.

RESULTS

Of 137 cirrhotic hospitalized patients, 121 cirrhotic patients (88.3 %) with AKI-prone conditions were included with mean age of 57.3 ± 14.7 years. Thirty-five patients (29 %) developed AKI within 72 h of admission. The causes of AKI were prerenal azotemia (68.6 %), acute tubular necrosis (25.7 %), hepatorenal syndrome (5.7 %), respectively. The mean uNGAL level was significantly higher in the patients who developed AKI compared with those who did not (290.6 ± 356.3 vs. 54.4 ± 73.7 ng/mL; P = 0.0001). The AUC of uNGAL for diagnosing AKI was 0.83 (95 % [CI]: 0.76-0.91) with the optimal cut-off level of 56 ng/mL, providing 77.1 % sensitivity and 73.3 % specificity. Fourteen percent of subjects died during the 30-day follow-up period. The mean uNGAL levels were significantly higher in the mortality group. The AUC of uNGAL in predicting mortality was 0.75 (95 % [CI]: 0.66-0.85), with a best cut-off level of 72 ng/mL providing 70.6 % sensitivity and 69.2 % specificity. However, in multivariate logistic regression analysis, uNGAL is not an independent factor for 30-day liver-related mortality prediction.

CONCLUSIONS

uNGAL is a valid marker for the early detection of AKI in hospitalized cirrhotic patients with AKI-prone conditions; however, its level could not independently predict 30-day liver-related mortality.

Whole-blood neutrophil gelatinase-associated lipocalin to predict adverse events in acute kidney injury: A prospective observational cohort study

PURPOSE

Acute kidney injury is common in intensive care units and is associated with increased morbidity and mortality. We evaluated the ability of whole-blood neutrophil gelatinase-associated lipocalin (wbNGAL) to predict mortality and need for renal replacement therapy (RRT) in critically ill patients with kidney dysfunction.

METHODS

We prospectively enrolled adult patients in 5 Canadian intensive care units. We measured wbNGAL at the time of enrollment to determine whether NGAL concentration could predict the primary composite outcome of death or need for RRT by day 30 in addition to other secondary outcomes.

RESULTS

We recruited 234 patients; 227 were included in the analysis. In a multivariable model, wbNGAL did not predict 30-day mortality or need for RRT (odds ratio, 1.05; 95% confidence interval, 0.99-1.12). Neutrophil gelatinase-associated lipocalin was similar in patients who died (654 [303-1180] ng/mL) vs those who survived (541.5 [255.5-1080] ng/mL, P=.26) by 90 days. Whole-blood NGAL poorly predicted the primary outcome (area under receiver operator curve, 0.65; 95% confidence interval, 0.58-0.73).

CONCLUSIONS

In a cohort of critically ill patients with abnormal kidney function, wbNGAL was not effective in the prediction of death or RRT within 30 days. These data do not support the use of this biomarker for the detection of clinical outcomes in this population.

Acute Kidney Injury in Liver Disease: Role of Biomarkers

Acute kidney injury (AKI) is a common complication in patients with advanced cirrhosis and is associated with significant mortality. The most common etiologies of AKI in this setting are prerenal azotemia, acute tubular necrosis, and hepatorenal syndrome. Despite the overall poor outcomes of patients with cirrhosis and AKI, potentially efficacious therapies exist but must be tailored to the specific AKI etiology. Unfortunately, determining the etiology of AKI in the setting of cirrhosis is notoriously difficult. Many of the standard diagnostic tools, such as urine microscopy and the fractional excretion of sodium, have traditionally been ineffective. Novel biomarkers of kidney tubular injury may be able to assist with differential diagnosis and the appropriate targeting of treatments by distinguishing structural from functional causes of AKI. In recent studies, both urinary neutrophil gelatinase-associated lipocalin and interleukin-18 have shown the ability to distinguish hepatorenal syndrome from prerenal azotemia and acute tubular necrosis. In addition, multiple biomarkers, including neutrophil gelatinase-associated lipocalin and interleukin-18, have demonstrated the ability to independently predict both progression of AKI and mortality. Critically, recent research also indicated that commonly available tests, fractional excretion of sodium and proteinuria, may also be able to distinguish etiologies of AKI in cirrhosis, but diagnostic cutoffs must be re-conceptualized specifically to this unique AKI setting.

Updates on pathogenesis, diagnosis and treatment of hepatorenal syndrome

Hepatorenal syndrome (HRS) is one of the most detrimental conditions in patients with end stage liver cirrhosis and acute liver failure, with high morbidity and mortality. The pathophysiology of HRS is complex and has not been fully elucidated. The therapeutic approaches for HRS are limited, among them, terlipressin in combination with albumin infusion is the first line choice. Liver transplantation remains the most effective treatment method. Patients with HRS often experience poor prognosis and have low survival, and early diagnosis of HRS may play a critical role in making treatment plans and improving the prognosis. Currently, it is needed to enhance the reliability of diagnostic methods and the feasibility of therapeutic regimens, which can improve the quality of life and reduce the family and social financial burden. The aim of this review is to summarize the recent advances in understanding the pathophysiology, diagnosis and management of HRS.

Neutrophil Gelatinase Associated Lipocalin (NGAL) - a biomarker of renal dysfunction in patients with liver cirrhosis: Do we have enough proof?

RATIONALE

Renal dysfunction has a serious impact on the natural evolution of liver cirrhosis. Treatment and prognosis may be improved if an early diagnosis could be established, and specific therapeutic interventions would be applied. Although RIFLE and AKIN classifications have been successfully implemented in the clinical practice of Nephrology and Intensive Care Units, these did not provide major improvements in patients with liver cirrhosis. In the last decade, various biomarkers of kidney injury have been assessed, and Neutrophil Gelatinase-Associated Lipocalin (NGAL) is one of the most promising and most studied novel biomarker.

OBJECTIVE

To offer a brief evaluation on current data on the utility of this biomarker in patients with liver cirrhosis.

METHODS AND RESULTS

We have searched through current literature and analyzed all significant full text articles on this topic.

DISCUSSIONS

NGAL and other new kidney injury molecules may be useful in patients with liver cirrhosis, particularly in identifying structural kidney dysfunction, but larger validation studies to confirm this observation are needed.

Renal dysfunction in cirrhosis is not just a vasomotor nephropathy

The short-term mortality of cirrhotic patients who develop renal dysfunction remains unacceptably high, and as such the treatment of this condition is an unmet need. Although features of kidney injury are well recognized in these patients, the pathophysiology is complex and not completely understood. Improved understanding of the pathophysiological mechanisms involved in renal dysfunction occurring on a background of cirrhosis is key to developing effective treatment strategies to improve survival. Renal dysfunction due to hepatorenal syndrome (HRS) is characteristic of cirrhosis. Our current understanding is that HRS is functional in nature and occurs as a consequence of hemodynamic changes associated with portal hypertension. However, there is evidence in the literature suggesting that, histologically, the kidneys are not always normal in the vast majority of patients who present with renal dysfunction on the background of cirrhosis. Furthermore, there is emerging data implicating nonvasomotor mechanisms in the pathophysiology of renal dysfunction in cirrhosis. This mini-review aims to present the evidence suggesting that factors other than hemodynamic dysregulation have an important role in the development of this major complication for patients with progressive cirrhosis.

Kidney injury in cirrhosis: pathophysiological and therapeutic aspects of hepatorenal syndromes

Acute kidney injury (AKI) is frequent in patients with cirrhosis. AKI and hyponatraemia are major determinants of the poor prognosis in advanced cirrhosis. The hepatorenal syndrome (HRS) denotes a functional and potential reversible impairment of renal function. Type 1 HRS, a special type of AKI, is a rapidly progressive AKI, whereas the renal function in type 2 HRS decreases more slowly. HRS is precipitated by factors such as sepsis that aggravate the effective hypovolaemia in decompensated cirrhosis, by lowering arterial pressure and cardiac output and enhanced sympathetic nervous activity. Therefore, attempts to prevent and treat HRS should seek to improve liver function and to ameliorate arterial hypotension, central hypovolaemia and cardiac output, and to reduce renal vasoconstriction. Ample treatment of HRS is important to prevent further progression and death, but as medical treatment only modestly improves long-term survival, these patients should always be considered for liver transplantation. Hyponatraemia, defined as serum sodium <130 mmol/L, is common in patients with decompensated cirrhosis. From a pathophysiological point of view, hyponatraemia is related to an impairment of renal solute-free water excretion most likely caused by an increased vasopressin secretion. Patients with cirrhosis mainly develop hypervolaemic hyponatraemia. Current evidence does not support routine use of vaptans in the management of hyponatraemia in cirrhosis.

Renal dysfunction in patients with cirrhosis: Where do we stand?

Patients with cirrhosis and renal failure are high-risk patients who can hardly be grouped to form precise instructions for diagnosis and treatment. When it comes to evaluate renal function in patients with cirrhosis, determination of acute kidney injury (AKI), chronic kidney disease (CKD) or AKI on CKD should be made. First it should be excluded the prerenal causes of AKI. All cirrhotic patients should undergo renal ultrasound for measurement of renal resistive index in every stage of liver dysfunction and urine microscopy for differentiation of all causes of AKI. If there is history of dehydration on the ground of normal renal ultrasound and urine microscopy the diuretics should be withdrawn and plasma volume expansion should be tried with albumin. If the patient does not respond, the correct diagnosis is HRS. In case there is recent use of nephrotoxic agents or contrast media and examination shows shock, granular cast in urinary sediment and proteinuria above 0.5 g daily, acute tubular necrosis is the prominent diagnosis. Renal biopsy should be performed when glomerular filtration rate is between 30-60 mL/min and there are signs of parenchymal renal disease. The acute renal function is preferable to be assessed with modified AKIN. Patients with AKIN stage 1 and serum creatinine ≥ 1.5 mg/dL should be at close surveillance. Management options include hemodynamic monitoring and management of fluid balance and infections, potentially driving to HRS. Terlipressin is the treatment of choice in case of established HRS, administered until there are signs of improvement, but not more than two weeks. Midodrine is the alternative for therapy continuation or when terlipressin is unavailable. Norepinephrine has shown similar effect with terlipressin in patients being in Intensive Care Unit, but with much lower cost than that of terlipressin. If the patient meets the requirements for transplantation, dialysis and transjugular intrahepatic portosystemic shunt are the bridging therapies to keep the transplant candidate in the best clinical status. The present review clarifies the latest therapeutic modalities and the proposed recommendations and algorithms in order to be applied in clinical practice.

The role of neutrophils in the development of liver diseases

Liver disease encompasses a wide variety of liver conditions, including liver failure, liver cirrhosis and a spectrum of acute and chronic hepatitis, such as alcoholic, fatty, drug, viral and chronic hepatitis. Liver injury is a primary causative factor in liver disease; generally, these factors include direct liver damage and immune-mediated liver injury. Neutrophils (also known as neutrophilic granulocytes or polymorphonuclear leukocytes (PMNs)) are the most abundant circulating white blood cell type in humans, and PMNs are a major innate immune cell subset. Inappropriate activation and homing of neutrophils to the microvasculature contributes to the pathological manifestations of many types of liver disease. This review summarizes novel concepts of neutrophil-mediated liver injury that are based on current clinical and animal model studies.

The role of neutrophils in the development of liver diseases

Liver disease encompasses a wide variety of liver conditions, including liver failure, liver cirrhosis and a spectrum of acute and chronic hepatitis, such as alcoholic, fatty, drug, viral and chronic hepatitis. Liver injury is a primary causative factor in liver disease; generally, these factors include direct liver damage and immune-mediated liver injury. Neutrophils (also known as neutrophilic granulocytes or polymorphonuclear leukocytes (PMNs)) are the most abundant circulating white blood cell type in humans, and PMNs are a major innate immune cell subset. Inappropriate activation and homing of neutrophils to the microvasculature contributes to the pathological manifestations of many types of liver disease. This review summarizes novel concepts of neutrophil-mediated liver injury that are based on current clinical and animal model studies.