Recent advances in our understanding of hepatorenal syndrome

Hepatorenal Syndrome in Cirrhosis

Hepatorenal syndrome (HRS) is a form of kidney dysfunction that characteristically occurs in liver cirrhosis. It is characterized by a marked impairment of kidney function in response to circulatory and hemodynamic alterations that occur in advanced stages of liver cirrhosis, aggravated by systemic inflammation and bacterial translocation. The classical definitions of the types of HRS have been recently revisited and 2 forms of HRS have been redefined: the acute form, referred to as acute kidney injury (HRS-AKI), and the chronic form, referred to as chronic kidney disease. HRS-AKI is one of the most severe forms of AKI in patients with cirrhosis and it consists of an abrupt impairment of kidney function, frequently triggered by an infection, appearing in the setting of advanced decompensated cirrhosis. Differential diagnosis with other causes of AKI is crucial because HRS-AKI requires a specific treatment. Differential diagnosis with AKI-acute tubular necrosis may be challenging and kidney biomarkers may be useful in this setting. Treatment of HRS-AKI is based on the administration of vasoconstrictor drugs in combination with volume expansion with albumin. Prognosis of HRS-AKI is poor, and the ideal definitive treatment consists of liver transplantation or simultaneous liver-kidney transplantation. HRS-AKI has a big impact on patients' quality of life. Management of HRS-AKI remains challenging in specific situations such as alcohol-associated hepatitis or metabolic-associated steatotic liver disease cirrhosis. Developing preventive measures for HRS-AKI, improving its early identification, discovering new biomarkers for differential diagnosis, and improving the response to therapy are some of the unmet needs in the field of HRS-AKI.

VWF/ADAMTS13 Ratio as a Potential Predictive Biomarker for Acute Kidney Injury Onset in Cirrhosis

AIM

We investigated the von Willebrand factor to ADAMTS13 ratio (von Willebrand factor [VWF]:Ag/ADAMTS13:AC) as a potential biomarker for the outcomes of acute kidney injury (AKI) in liver cirrhosis (LC).

METHODS

This retrospective cross-sectional study included patients with LC who developed AKI (AKI group: n = 91) and patients with LC who did not develop AKI [non-AKI (NAKI) group, n = 91] as a control group. Plasma levels of the von Willebrand factor antigen (Ag) and ADAMTS13 activity (AC) were measured in patients with AKI or NAKI. Moreover, risk factors for onset of AKI, AKI-associated 90-day mortality, and poor AKI treatment response were identified.

RESULTS

The AKI group had a significantly higher VWF:Ag/ADAMTS13:AC than the NAKI group. Values of VWF:Ag/ADAMTS13:AC ≥ 5.7 were identified as risk factors for AKI onset in patients with LC (odds ratio [OR] 2.56; 95% CI 1.26-4.99; p < 0.001). Among patients with AKI, values of VWF:Ag/ADAMTS13:AC ≥ 9.0 were identified as risk factors for 90-day mortality (OR 6.83; 95% CI 2.32-20.10; p < 0.001). Cumulative survival was significantly lower in those with high (≥ 9.0) than in those with low (< 9.0) VWF:Ag/ADAMTS13:AC. Furthermore, values of VWF:Ag/ADAMTS13:AC ≥ 7.4 were identified as risk factors for poor treatment response (OR 4.2; 95% CI 1.39-12.70; p < 0.001). The treatment response rates were significantly higher in those with low (< 7.4) VWF:Ag/ADAMTS13:AC than in those with high (≥ 7.4) VWF:Ag/ADAMTS13:AC.

CONCLUSION

VWF:Ag/ADAMTS13:AC potentially predicts the onset, prognosis, and treatment response of AKI in patients with LC.

Controversies regarding albumin therapy in cirrhosis

Albumin is the most abundant protein in the human body and is synthetized exclusively by the liver. Therefore, serum albumin levels are reduced in acute and/or chronic liver disease. In cirrhosis, low levels of albumin predict the outcome. In advanced cirrhosis, the quality of albumin is decreased due to high oxidative stress and a proinflammatory state. Therefore, the administration of i.v. albumin would seem to be of pathophysiological relevance and benefit. Yet, the questions that remain are who, when, how much, and how often. While albumin infusion is recommended after large-volume paracentesis, at diagnosis of spontaneous bacterial peritonitis, in acute kidney injury, and in hepatorenal syndrome, the amount and schedule of albumin to be administered require refinement, particularly given complications related to volume overload that have become increasingly apparent. Other indications for albumin such as infections other than spontaneous bacterial peritonitis, hyponatremia, HE, prevention of poor outcomes in hospitalized, and in outpatients with cirrhosis are still debated. The results of studies in these settings are either negative, controversial, or inconclusive. This sheds some doubts regarding the use of albumin as a "one size fits all" strategy. The indication and patient selection are crucial and not always intuitive. The amount and frequency also seem to play a role in the success or failure of albumin. This review will critically discuss the evidence and underline areas where there are indications for albumin use and others where evidence is still insufficient and will have to await the development/results of randomized controlled trials.

Austrian consensus on the diagnosis and management of portal hypertension in advanced chronic liver disease (Billroth IV)

The Billroth IV consensus was developed during a consensus meeting of the Austrian Society of Gastroenterology and Hepatology (ÖGGH) and the Austrian Society of Interventional Radiology (ÖGIR) held on the 26th of November 2022 in Vienna.Based on international recommendations and considering recent landmark studies, the Billroth IV consensus provides guidance regarding the diagnosis and management of portal hypertension in advanced chronic liver disease.

Diagnostic and prognostic performance of urinary neutrophil gelatinase-associated lipocalin in patients with cirrhosis and acute kidney injury

BACKGROUND AND AIMS

Acute kidney injury (AKI) commonly occurs in patients with decompensated cirrhosis. Urinary neutrophil gelatinase-associated lipocalin (uNGAL) could help discriminate between different etiologies of AKI. The aim of this study was to investigate the use of uNGAL in (1) the differential diagnosis of AKI, (2) predicting the response to terlipressin and albumin in patients with hepatorenal syndrome-AKI (HRS-AKI), and (3) predicting in-hospital mortality in patients with AKI.

APPROACH AND RESULTS

One hundred sixty-two consecutive patients with cirrhosis and AKI were included from 2015 to 2020 and followed until transplant, death, or 90 days. Standard urinary markers and uNGAL were measured. Data on treatment, type, and resolution of AKI were collected. Thirty-five patients (21.6%) had prerenal AKI, 64 (39.5%) HRS-AKI, 27 (16.7%) acute tubular necrosis-AKI (ATN-AKI), and 36 (22.2%) a mixed form of AKI. Mean values of uNGAL were significantly higher in ATN-AKI than in other types of AKI (1162 ng/ml [95% CI 423-2105 ng/ml] vs. 109 ng/ml [95% CI 52-192 ng/ml]; p  < 0.001). uNGAL showed a high discrimination ability in predicting ATN-AKI (area under the receiver operating characteristic curve, 0.854; 95% CI 0.767-0.941; p  < 0.001). The best-performing threshold was found to be 220 ng/ml (sensitivity, 89%; specificity, 78%). The same threshold was independently associated with a higher risk of nonresponse (adjusted OR [aOR], 6.17; 95% CI 1.41-27.03; p  = 0.016). In multivariable analysis (adjusted for age, Model for End-Stage Liver Disease, acute-on-chronic liver failure, leukocytes, and type of AKI), uNGAL was an independent predictor of in-hospital mortality (aOR, 1.74; 95% CI 1.26-2.38; p  = 0.001).

CONCLUSIONS

uNGAL is an adequate biomarker for making a differential diagnosis of AKI in cirrhosis and predicting the response to terlipressin and albumin in patients with HRS-AKI. In addition, it is an independent predictor of in-hospital mortality.

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.

Do old urinary biomarkers have a place in the new definition of hepatorenal syndrome in the Egyptian cirrhotic patients? A single-center experience

Background

Hepatorenal syndrome is still a diagnosis of exclusion despite new classification.

Aims

To validate the accuracy of urinary neutrophil gelatinase-associated lipocalin, interleukin-18, and kidney injury molecule-1 in the new diagnostic criteria of hepatorenal syndrome in Egyptian patients with hepatitis C virus-related liver cirrhosis using serum creatinine as a gold standard test for acute kidney injury.

Methods

One-hundred twenty cirrhotic patients with ascites were recruited and divided into two groups depending on the presence or absence of renal impairment, and 40 age- and sex-matched cirrhotic patients without ascites used as controls participated in the study. Urinary biomarkers were measured and compared with conventional biomarkers used to assess kidney function (serum creatinine, estimated glomerular filtration rate).

Results

The mean urinary neutrophil gelatinase-associated lipocalin, interleukin-18, and kidney injury molecule-1 were statistically significantly higher in patients with hepatorenal syndrome and were found to be helpful in the early detection with cutoff values of 125 ng/ml, 34.8 pg/ml, and 3.1 pg/ml, respectively.

Conclusions

Urinary neutrophil gelatinase-associated lipocalin, interleukin-18, and kidney injury molecule-1 levels are higher in patients with cirrhotic ascites complicated by HRS-AKI using the new definition of HRS, but IL-18 has lower sensitivity and specificity for the prediction of HRS-AKI as compared to NGAL and KIM-1.

Portal hypertension in cirrhosis: Pathophysiological mechanisms and therapy

Portal hypertension, defined as increased pressure in the portal vein, develops as a consequence of increased intrahepatic vascular resistance due to the dysregulation of liver sinusoidal endothelial cells (LSECs) and hepatic stellate cells (HSCs), frequently arising from chronic liver diseases. Extrahepatic haemodynamic changes contribute to the aggravation of portal hypertension. The pathogenic complexity of portal hypertension and the unsuccessful translation of preclinical studies have impeded the development of effective therapeutics for patients with cirrhosis, while counteracting hepatic and extrahepatic mechanisms also pose a major obstacle to effective treatment. In this review article, we will discuss the following topics: i) cellular and molecular mechanisms of portal hypertension, focusing on dysregulation of LSECs, HSCs and hepatic microvascular thrombosis, as well as changes in the extrahepatic vasculature, since these are the major contributors to portal hypertension; ii) translational/clinical advances in our knowledge of portal hypertension; and iii) future directions.

Acute Decompensation and Acute-on-Chronic Liver Failure

Liver cirrhosis is a major healthcare problem. Acute decompensation, and in particular its interplay with dysfunction of other organs, is responsible for the majority of deaths in patients with cirrhosis. Acute decompensation has different courses, from stable decompensated cirrhosis over unstable decompensated cirrhosis to pre-acute-on-chronic liver failure and finally acute-on-chronic liver failure, a syndrome with high short-term mortality. This review focuses on the recent developments in the field of acute decompensation and acute-on-chronic liver failure.

Renal Function Parameters and Serum Sodium Enhance Prediction of Wait-List Outcomes in Pediatric Liver Transplantation

BACKGROUND AND AIMS

Reliance on exception points to prioritize children for liver transplantation (LT) stems from concerns that the Pediatric End-Stage Liver Disease (PELD) score underestimates mortality. Renal dysfunction and serum sodium disturbances are negative prognosticators in adult LT candidates and various pediatric populations, but are not accounted for in PELD. We retrospectively evaluated the effect of these parameters in predicting 90-day wait-list death/deterioration among pediatric patients (<12 years) listed for isolated LT in the United States between February 2002 and June 2018.

APPROACH AND RESULTS

Among 4,765 patients, 2,303 (49.3%) were transplanted, and 231 (4.8%) died or deteriorated beyond transplantability within 90 days of listing. Estimated glomerular filtration rate (eGFR) (hazard ratio [HR] 1.09 per 5-unit decrease, 95% confidence interval [CI] 1.06-1.10) and dialysis (HR 7.24, 95% CI 3.57-14.66) were univariate predictors of 90-day death/deterioration (P < 0.001). The long-term benefit of LT persisted in patients with renal dysfunction, with LT as a time-dependent covariate conferring a 2.4-fold and 17-fold improvement in late survival among those with mild and moderate-to-severe dysfunction, respectively. Adjusting for PELD, sodium was a significant nonlinear predictor of outcome, with 90-day death/deterioration risk increased at both extremes of sodium (HR 1.20 per 1-unit decrease below 137 mmol/L, 95% CI 1.16-1.23; HR per 1-unit increase above 137 mmol/L 1.13, 95% CI 1.10-1.17, P < 0.001). A multivariable model incorporating PELD, eGFR, dialysis, and sodium demonstrated improved performance and superior calibration in predicting wait-list outcomes relative to the PELD score.

CONCLUSIONS

Listing eGFR, dialysis, and serum sodium are potent, independent predictors of 90-day death/deterioration in pediatric LT candidates, capturing risk not accounted for by PELD. Incorporation of these variables into organ allocation systems may highlight patient subsets with previously underappreciated risk, augment ability of PELD to prioritize patients for transplantation, and ultimately mitigate reliance on nonstandard exceptions.

Prevalence and short-term outcome of hepatorenal syndrome: A 9-year experience in a high-complexity hospital in Colombia

BACKGROUND & AIMS

Hepatorenal syndrome is a rare entity that is part of the complications of liver cirrhosis in its more severe stages. Without treatment, its mortality rate increases significantly. Terlipressin is considered to be the therapy of choice until the need of a liver transplant. The aim is to determine its prevalence, define patients' characteristics, triggers and 90-day survival, according to the type of managements established.

METHOD

This was a retrospective cohort study conducted in Colombia. It included patients with cirrhosis and acute kidney injury who met hepatorenal syndrome criteria, reaching 28 patients from 2007 to 2015. Groups were categorized according the type of hepatorenal syndrome and treatment. Demographic and trigger factors were evaluated to characterize the population. Treatment outcomes with terlipressin vs norepinephrine were analyzed up to a 90-day survival, using log Rank test. Continuous variables needed Student's T and Mann Whitney's U tests and categorical variables, Chi2 test. A value of p <0.05 and a power of 85% was considered. The data was analyzed in the SPSS version 23 software.

RESULTS

117 patients with cirrhosis developed renal injury; of these 23.9% were diagnosed with Hepatorenal Syndrome (67.8% type1; 32.1% type2). The presence of ascites was 100% in HRS2 and 84% in HRS1 (p = 0.296). The main trigger in both types was paracentesis greater than 5 liters in the last 4 weeks (39.3%). In total, 35% of the patients received renal replacement therapy and 14% underwent a hepatic transplant. Type 1 was more frequent (63% received terlipressin; 21% norepinephrine). The total complete response was 36% (Type2 66.6% vs. Type1 18.7%) (p = 0.026). In contrast, the overall mortality was of 67.8% at 90-day of follow-up (89.4% Type1 vs. 22% Type2) (p = <0.001). We found a lower mortality rate in patients treated with terlipressin than treated with norepinephrine (p = 0.006).

CONCLUSION

There is scarce clinical and epidemiological information about this condition in Colombia. A significant difference between the two drugs cannot be stipulated due to the limitation in the sample size of our study. The general mortality at a 90-day follow-up was high, being higher in patients with HRS1. While the results of this study are suggestive of clinical information for HRS patients in the Colombian population, they should also be interpreted with caution, therefore further multicenter studies should be performed.

Short-term mortality in patients with cirrhosis of the liver and acute kidney injury: A prospective observational study

INTRODUCTION

Renal failure is a common and severe complication of cirrhosis and confers poor prognosis. Serum creatinine is the most practical biomarker of renal function. Serum creatinine estimation in cirrhosis of the liver is affected by decreased formation, increased tubular secretion, increased volume of distribution, and interference by elevated bilirubin. Studies on the prognosis of cirrhotic patients using creatinine kinetics as a definition of acute kidney injury (AKI) proposed by the International Ascites Club are limited.

METHODS

In this single-center prospective observational study, decompensated cirrhotics with AKI defined by the International Ascites Club as the rise of serum creatinine ≥ 0.3 mg/dL within 48 h of admission or increase of serum creatinine ≥ 50% from stable baseline creatinine over the previous 3 months were followed and assessed for the development of complications during hospital course and in-hospital and 30-day mortality.

RESULTS

AKI developed in 142 out of 499 (28.45%) patients with cirrhosis. Twenty patients were excluded. The most common etiology of cirrhosis was alcohol (n = 64, 52%), and ascites was present in 115 (94%) patients. Eighty-two (67.21%) patients presented with AKI at the time of admission. Thirty-day mortality was 46.72% (57/122 patients). Hepatorenal syndrome had the highest mortality followed by AKI related to infection. Presence of jaundice and hepatic encephalopathy (HE) was associated with poor survival with adjusted hazard ratio of 3.54 and 2.17, respectively. On bivariate logistic regression analysis, jaundice, HE, type of AKI, AKI stage at maximum creatinine, bilirubin, serum glutamic oxaloacetic transaminase (SGOT), international normalized ratio (INR), and Child-Turcotte-Pugh (CTP) and model for end-stage liver disease (MELD) scores were predictors of mortality (p < 0.05). Sensitivity, specificity, and accuracy of MELD > 29 and CTP score > 11 were 75.44%, 82%, and 78.70% and 66.67%, 81.54%, and 74.60%, respectively for predicting 30-day mortality.

CONCLUSION

Development of AKI as defined by the International Ascites Club in cirrhosis confers high short-term mortality. Jaundice, HE, AKI stage, creatinine at enrollment, bilirubin, CTP, and MELD score were the predictors of mortality. Bullet points of the study highlights What is already known? • Renal failure is a common and severe complication of cirrhosis. • Serum creatinine is the most practical biomarker of renal function but it has many limitations in cirrhotic patients. • Creatinine kinetics-based definition of acute kidney injury (AKI) was proposed by the International Ascites Club. What is new in this study? • Short-term mortality (30 days) in decompensated cirrhotic patients with AKI as defined by the International Ascites Club using creatinine kinetics was high. • AKI due to hepatorenal syndrome (HRS) has the highest short-term (30 days) mortality followed by AKI due to infection in decompensated cirrhosis. • Detection of AKI using creatinine kinetics-based definition may prompt an early appropriate intervention. What are the future clinical and research implications of study findings? • Creatinine kinetics-based definition of AKI diagnose renal injury at an earlier stage; an appropriate intervention should be initiated at the earliest in these patients to improve patient survival.

Could KIM-1 and NGAL levels predict acute kidney injury after paracentesis? - preliminary study

Background

Kidney dysfunction is a common complication in patients with severe liver cirrhosis. There is a need for discovery and validation of novel biomarkers for earlier AKI detection. The aim of this study was to determine if tubular injury markers: NGAL and KIM-1 could be helpful in the early diagnosis of AKI in patients undergoing therapeutic paracentesis.

Methods

This preliminary study included 24 adult patients diagnosed with liver cirrhosis who had been hospitalized due to massive ascites requiring paracentesis. Pre- and post-paracentesis plasma samples were taken from each patient and biomarkers were measured.

Results

Before paracentesis, the levels of serum and urinary NGAL were similar between patients and controls; while urinary KIM-1 was markedly increased in liver cirrhotic patients (0.76 vs. 0.24 ng/ml; respectively). Although urinary NGAL levels in AKI patients were 5-time greater than in non-AKI subgroup, the difference did not reach statistical significance (13.2 vs 1.5 pg/mL, p = 0.06). Serum NGAL level, post-procedure, was 3 times greater in AKI subgroup.

Conclusion

Kidney injury markers, especially serum NGAL, may be useful for the early detection of AKI. However, further research is required to determine if biomarkers of kidney injury may help identify patients with cirrhosis who would most likely benefit from early AKI prevention and treatment.

Acute kidney injury is associated with higher mortality and healthcare costs in hospitalized patients with cirrhosis

INTRODUCTION AND OBJECTIVES

AKI is known to be associated with increased risk of mortality, however limited information is available on how AKI impacts healthcare costs and resource utilization in hospitalized patients with cirrhosis. Previous studies have had variable definitions of AKI, resulting in inconsistent reporting of the true impact of AKI in patients with cirrhosis.

METHODS

Data from the Nationwide Inpatient Sample (NIS) which contains data from 44 states and 4378 hospitals, accounting for over 7 million discharges were analyzed. The inclusion data were all discharges in the 2012 NIS dataset with a discharge diagnosis of cirrhosis.

RESULTS

A total of 32,605 patients were included in the analysis, incidence of AKI was 12.12% in patients with cirrhosis. Crude mortality was much higher for patients with cirrhosis and AKI (14.9% vs. 1.8%, OR 9.42, p<0.001) than for patients without AKI. In addition, mean LOS was longer (8.5 vs. 4.3 days, p<0.001) and median total hospital charges were higher for patients with AKI ($43,939 vs. $22,270, p<0.001). In multivariate logistic regression, controlling for covariates and mortality risk score, sepsis, ascites and SBP were predictors of AKI.

CONCLUSIONS

AKI is relatively common in hospitalized patients with cirrhosis. Presence of AKI results in significantly higher inpatient mortality as well as LOS and resource utilization. Median hospitalization cost was twice as high in AKI patients. Early identification of patients at high risk for AKI should be implemented to reduce mortality and contain costs. Prognosis could be enhanced by utilizing biomarkers which could rapidly detect AKI.

Liver Cirrhosis Complications Management at the Emergency Department

BACKGROUND AND AIMS

Liver cirrhosis (LC) of any origin has always been a source of several emergencies for physicians working at the Emergency Department (ER). LC patients can present with several complications that are sometimes difficult to recognize and treat. Thus, we reviewed the literature evidence for the diagnosis and management of several LC related emergencies.

METHODS

We conducted a search on the main medical databases for papers, reviews, metanalyses, case series, and RCTs using the following keywords and their associations: liver cirrhosis, variceal hemorrhage, ascites, hepatic encephalopathy, spontaneous bacterial peritonitis, hepato-renal syndrome, emergency.

RESULTS

Main LC emergencies are upper gastrointestinal hemorrhage, decompensated ascites and spontaneous bacterial peritonitis, hepatic encephalopathy, hepato-renal syndrome. Their management is partly medical and interventional. Very often, the final cure of some complications, such as hepato-renal syndrome, is represented by liver transplantation.

CONCLUSION

Although LC prevalence is going to fall in the following years, due to HBV and HCV optimized treatments, its complications represent a significant admission percentage at the ER and challenge for physicians' skills.

Dobutamine reverses the cardio-suppressive effects of terlipressin without improving renal function in cirrhosis and ascites: a randomized controlled trial

Acute kidney injury and hepatorenal syndrome (HRS) are frequent complications in patients with cirrhosis and ascites. First-line treatment is terlipressin, which reverses HRS in ~40% of patients but also lowers cardiac output (CO). We aimed to investigate whether reversing the cardio-suppressive effect of terlipressin with the β-adrenoceptor agonist dobutamine would increase CO and thereby increase the glomerular filtration rate (GFR). We randomized 25 patients with cirrhosis, ascites, and impaired renal function (2:2:1): group A received terlipressin followed by the addition of dobutamine; group B received dobutamine and terlipressin as monotherapies; and group C received placebo. Renal and cardiac functions were assessed during 8 clearance periods of 30 min, and concentrations of vasoactive hormones were measured. Dobutamine as a monotherapy increased CO (1.03 L/min, P < 0.01) but had no significant effects on GFR. Renin (P < 0.05), angiotensin II (P < 0.005), and aldosterone (P < 0.05) increased after dobutamine infusion. Terlipressin as a monotherapy improved GFR (18.9 mL·min^-1·m^-2, P = 0.005) and mean arterial pressure (MAP) (14 mmHg, P = 0.001) but reduced CO (-0.92 L/min, P < 0.005) and renin (P < .005). A combined treatment of dobutamine and terlipressin had a positive effect on CO (1.19 L/min, P < 0.05) and increased renin (P < 0.005), angiotensin II (P < 0.005), and aldosterone (P < 0.05), but it had no significant effects on MAP or GFR. Dobutamine reversed the cardio-suppressive effect of terlipressin in cirrhosis, ascites, and impaired renal function. However, dobutamine reduced peripheral vascular resistance, activated renin-angiotensin-aldosterone system, and did not improve GFR compared with terlipressin as a monotherapy. Therefore, dobutamine cannot be recommended in cirrhosis and ascites.NEW & NOTEWORTHY This study shows that the cardio-suppressive effects of the vasopressin receptor agonist terlipressin can be reversed by dobutamine. This is a novel observation in patients with decompensated cirrhosis. Furthermore, we show that dobutamine reduced the peripheral vascular resistance and activated the renin-angiotensin system, whereas renal function was not further improved by terlipressin alone.

Functional magnetic resonance imaging-based assessment of terlipressin vs. octreotide on renal function in cirrhotic patients with acute variceal bleeding (CHESS1903): study protocol of a multicenter randomized controlled trial

BACKGROUND

Acute variceal bleeding is one of the critical complications in patients with liver cirrhosis. Severe renal vasoconstriction in consequence of low peripheral vascular resistance triggers the reduction of glomerular filtration rate (GFR), and thus induces acute kidney injury (AKI)/hepato-renal syndrome (HRS). Terlipressin and octreotide have been used in the management of cirrhotic patients with variceal bleeding. Also, terlipressin has been recommended as the international first-line pharmacological therapy for the treatment of HRS. In addition, the use of renal functional magnetic resonance imaging (fMRI) has become increasingly prevalent in research and clinical applications. However, the renal function-protective effect of terlipressin and octreotide and the value of fMRI in monitoring renal function remains unclear in patients with cirrhosis undergoing acute variceal bleeding.

METHODS

This is a multicenter, randomized controlled trial (RCT). Participants will be 1:1 assigned randomly into either terlipressin or octreotide groups. Sixty participants with clinically and/or pathologically diagnosed cirrhosis and active gastroesophageal variceal bleeding (GVB) will be recruited in several sites in China. Participants will receive either the treatment of terlipressin or octreotide after assigned into each group. The primary end point for the trial is the renal function. The secondary end points are (I) renal perfusion; (II) renal blood oxygenation; (III) failure to control bleeding; (IV) intra-hospital rebleeding; (V) intra-hospital mortality; (VI) adverse events (AE); (VII) overall survival. Statistical analysis including multivariate Cox regression, Kaplan-Meier analysis with log-rank test, etc. will be conducted.

DISCUSSION

The study will provide new insight into the protection of renal function in the process of the treatment of variceal bleeding in patients with cirrhosis.

TRIAL REGISTRATION NUMBER

NCT04028323.

Neutrophil Gelatinase-Associated Lipocalin for Assessment of Acute Kidney Injury in Cirrhosis: A Prospective Study

Kidney biomarkers appear to be useful in differential diagnosis between acute tubular necrosis (ATN) and other types of acute kidney injury (AKI) in cirrhosis, particularly hepatorenal syndrome (HRS-AKI). Distinction is important because treatment is different. However, kidney biomarkers are still not used in clinical practice. The aim of the current study was to investigate the accuracy of several biomarkers in differential diagnosis of AKI and in predicting kidney outcome and patient survival. This was a prospective study of 320 consecutive cases of AKI in patients hospitalized for decompensated cirrhosis. Evaluation of AKI was made with a diagnostic algorithm that included identification and removal/treatment of precipitating factors and albumin administration (1 g/kg for 2 days) to patients with AKI stage 1B or greater. Urinary neutrophil gelatinase-associated lipocalin (NGAL), monomeric NGAL (mNGAL), interleukin-18, and standard biomarkers were measured at diagnosis and on days 3, 7, and 14. Of the 320 cases, 153 were hypovolemia-induced AKI (48%), 93 were HRS-AKI (29%), 39 were ATN (12%), and 35 were due to miscellaneous causes (11%). Among all biomarkers, urinary NGAL measured at day 3 had the greatest accuracy for differential diagnosis between ATN and other types of AKI (area under the receiver operating characteristic curve, 0.87; 95% confidence interval, 0.78-0.95). The cutoff with the best predictive accuracy for ATN diagnosis was 220 µg/g creatinine. Progression of AKI during hospitalization was associated with persistently high NGAL levels, and NGAL was an independent predictive factor of AKI progression. Likewise, NGAL was also an independent predictive factor of 28-day mortality together with Model for End-Stage Liver Disease score. Conclusion: These results support the use of NGAL in clinical practice within the context of a diagnostic algorithm for differential diagnosis of AKI and outcome prediction in cirrhosis.

Impact of Chronic Kidney Disease on Outcomes in Cirrhosis

We hypothesize that the prevalence of chronic kidney disease (CKD) among patients with cirrhosis has increased due to the increased prevalence of CKD-associated comorbidities, such as diabetes. We aimed to assess the characteristics of hospitalized patients with cirrhosis with CKD and its impact on renal and patient outcomes. The North American Consortium for the Study of End-Stage Liver Disease (NACSELD) prospectively enrolled nonelectively admitted patients with cirrhosis and collected data on demographics, laboratory results, in-hospital clinical course, and postdischarge 3-month outcomes. CKD positive (CKD+) patients, defined as having an estimated glomerular filtration rate (eGFR; Modification of Diet in Renal Disease-4 variable formula) of ≤60 mL/minute for >3 months, were compared with chronic kidney disease negative (CKD-) patients for development of organ failures, hospital course, and survival. There were 1099 CKD+ patients (46.8% of 2346 enrolled patients) who had significantly higher serum creatinine (2.21 ± 1.33 versus 0.83 ± 0.21 mg/dL in the CKD- group) on admission, higher prevalence of nonalcoholic steatohepatitis cirrhosis etiology, diabetes, refractory ascites, and hospital admissions in the previous 6 months compared with the CKD- group (all P < 0.001). Propensity matching (n = 922 in each group) by Child-Pugh scores (9.78 ± 2.05 versus 9.74 ± 2.04, P = 0.70) showed that CKD+ patients had significantly higher rates of superimposed acute kidney injury (AKI; 68% versus 21%; P < 0.001) and eventual need for dialysis (11% versus 2%; P < 0.001) than CKD- patients. CKD+ patients also had more cases of acute-on-chronic liver failure as defined by the NACSELD group, which was associated with reduced 30- and 90-day overall survival (P < 0.001 for both). A 10 mL/minute drop in eGFR was associated with a 13.1% increase in the risk of 30-day mortality. In conclusion, patients with CKD should be treated as a high-risk group among hospitalized patients with cirrhosis due to their poor survival, and they should be monitored carefully for the development of superimposed AKI.

Fluid Management in Acute Kidney Injury

Correction of intravascular hypovolemia is a key component of the prevention and management of acute kidney injury (AKI), but excessive fluid administration is associated with poor outcomes, including the development and progression of AKI. There is growing evidence that fluid administration should be individualized and take into account patient characteristics, nature of the acute illness and trajectories, and risks and benefits of fluids. Existing data support the preferential use of buffered solutions for fluid resuscitation of patients at risk of AKI who do not have hypochloremia. There is a limited role for albumin, and starches should be avoided. Fluids should only be administered until intravascular hypovolemia has been corrected and euvolemia has been achieved using the minimum amount of fluid required to achieve and maintain euvolemia. Oliguria alone should not be viewed as a trigger for fluid administration. If fluid overload occurs, fluid therapy needs to be discontinued, and fluid removal using diuretic agents or extracorporeal therapies should be considered.

Prioritization of Therapeutic Targets and Trial Design in Cirrhotic Portal Hypertension

Portal hypertension (PH) is the main driver of cirrhosis decompensation, the main determinant of death in patients with cirrhosis. PH results initially from increased intrahepatic vascular resistance. Subsequently, increased inflow from splanchnic vasodilation and increased cardiac output lead to a further increase in portal pressure (PP). Reducing PP in cirrhosis results in better outcomes. Removing the cause of cirrhosis might improve PP. However, this is a slow process and patients may continue to be at risk of decompensation. Additionally, for some chronic liver diseases, such as nonalcoholic fatty liver disease (NAFLD), etiological treatments are not yet available. Therefore, there is a need to develop better therapies specifically aimed at reducing PP. For over 35 years, the mainstay of such therapy has been the use of nonselective beta-blockers (NSBBs) that act by reducing portal venous inflow. Recently, many drugs (mainly targeting intrahepatic mechanisms) have shown promise in preclinical and early clinical studies and may act alone or synergistically with NSBBs in reducing PP in cirrhosis. The objective of this position paper is to propose a novel framework for the design of clinical trials (phase 1, 2, and 3) in patients with cirrhosis and PH and to prioritize targets and pharmacological therapies in this setting. We have focused the discussion on patients with compensated cirrhosis. The paper summarizes discussions held at The American Association for the Study of Liver Diseases (AASLD) Industry Colloquium in January 2018, with the participation of clinical and translational investigators, regulatory professionals, and industry partners.

Paracentesis-induced acute kidney injury in decompensated cirrhosis - prevalence and predictors

AIM OF THE STUDY

A subgroup of cirrhotic patients undergoing therapeutic paracentesis develop acute kidney injury (AKI) despite adequate colloidal replacement.The aim of the study was to determine the prevalence and predictors of paracentesis-induced AKI in cirrhotic patients with normal baseline renal parameters and adequate colloidal replacement.

MATERIAL AND METHODS

This prospective, observational analytical study was undertaken between April 2015 and April 2017. All patients undergoing therapeutic paracentesis were enrolled as per inclusion and exclusion criteria. Based on Acute Kidney Injury Network (AKIN) criteria for AKI, comparative analysis was performed between those developing and not developing AKI for demography, renal parameters, frequency and quantity of paracentesis per session. Univariate and multivariate regression analyses were performed to determine the predictors of AKI.

RESULTS

Altogether, 177 patients underwent 859 therapeutic paracenteses. Ninety-four paracentesis sessions resulted in an AKI (10.9%). The median number of paracenteses was 10 (range 1-25) and the median volume of fluid drained per paracentesis was 6 l (1-20 l). In univariate analysis, younger age (p < 0.02), higher MELD (Model For End-Stage Liver Disease) score (p < 0.0001), CTP (Child-Turcotte-Pugh) class C (p < 0.017) and prior history of renal dysfunction (p < 0.0001) were significantly associated with AKI. For each liter of fluid drained, the risk of AKI increased by 1.24 times. Frequency of paracentesis did not influence the AKI. In multivariate logistic regression, the significant predictors of AKI were past renal dysfunction, a higher MELD and volume of fluid tapped at paracentesis.

CONCLUSIONS

Post-paracentesis AKI occurs in 10.9% of cases, despite adequate colloid replacement. For each 1 l of fluid drained during paracentesis, the risk of AKI increased by 1.24 times.

Rho-kinase inhibitor coupled to peptide-modified albumin carrier reduces portal pressure and increases renal perfusion in cirrhotic rats

Rho-kinase (ROCK) activation in hepatic stellate cells (HSC) is a key mechanism promoting liver fibrosis and portal hypertension (PTH). Specific delivery of ROCK-inhibitor Y-27632 (Y27) to HSC targeting mannose-6-phosphate-receptors reduces portal pressure and fibrogenesis. In decompensated cirrhosis, presence of ascites is associated with reduced renal perfusion. Since in cirrhosis, platelet-derived growth factor receptor beta (PDGFRβ) is upregulated in the liver as well as the kidney, this study coupled Y27 to human serum albumin (HSA) substituted with PDGFRβ-recognizing peptides (pPB), and investigated its effect on PTH in cirrhotic rats. In vitro collagen contraction assays tested biological activity on LX2 cells. Hemodynamics were analyzed in BDL and CCl₄ cirrhotic rats 3 h, 6 h and 24 h after i.v. administration of Y27pPBHSA (0.5/1 mg/kg b.w). Phosphorylation of moesin and myosin light chain (MLC) assessed ROCK activity in liver, femoral muscle, mesenteric artery, kidney and heart. Three Y27 molecules were coupled to pPBHSA as confirmed by HPLC/MS, which was sufficient to relax LX2 cells. In vivo, Y27pPBHSA-treated rats exhibited lower portal pressure, hepatic vascular resistance without effect on systemic vascular resistance, but a tendency towards lower cardiac output compared to non-treated cirrhotic rats. Y27pPBHSA reduced intrahepatic resistance by reduction of phosphorylation of moesin and MLC in Y27pPBHSA-treated cirrhotic rats. Y27pPBHSA was found in the liver of rats up to 6 hours after its injection, in the HSC demonstrated by double-immunostainings. Interestingly, Y27pPBHSA increased renal arterial flow over time combined with an antifibrotic effect as shown by decreased renal acta2 and col1a1 mRNA expression. Therefore, targeting the ROCK inhibitor Y27 to PDGFRβ decreases portal pressure with potential beneficial effects in the kidney. This unique approach should be tested in human cirrhosis.

Left Ventricular Longitudinal Contractility Predicts Acute-on-Chronic Liver Failure Development and Mortality After Transjugular Intrahepatic Portosystemic Shunt

Acute deterioration of liver cirrhosis (e.g., infections, acute-on-chronic liver failure [ACLF]) requires an increase in cardiac contractility. The insufficiency to respond to these situations could be deleterious. Left ventricular global longitudinal strain (LV-GLS) has been shown to reflect left cardiac contractility in cirrhosis better than other parameters and might bear prognostic value. Therefore, this retrospective study investigated the role of LV-GLS in the outcome after transjugular intrahepatic portosystemic shunt (TIPS) and the development of ACLF. We included 114 patients (48 female patients) from the Noninvasive Evaluation Program for TIPS and Their Follow-Up Network (NEPTUN) cohort. This number provided sufficient quality and structured follow-up with the possibility of calculating major scores (Child, Model for End-Stage Liver Disease [MELD], Chronic Liver Failure Consortium acute decompensation [CLIF-C AD] scores) and recording of the events (development of decompensation episode and ACLF). We analyzed the association of LV-GLS with overall mortality and development of ACLF in patients with TIPS. LV-GLS was independently associated with overall mortality (hazard ratio [HR], 1.123; 95% confidence interval [CI],1.010-1.250) together with aspartate aminotransferase (HR, 1.009; 95% CI, 1.004-1.014) and CLIF-C AD score (HR, 1.080; 95% CI, 1.018-1.137). Area under the receiver operating characteristic curve (AUROC) analysis for LV-GLS for overall survival showed higher area under the curve (AUC) than MELD and CLIF-C AD scores (AUC, 0.688 versus 0.646 and 0.573, respectively). The best AUROC-determined LV-GLS cutoff was -16.6% to identify patients with a significantly worse outcome after TIPS at 3 months, 6 months, and overall. LV-GLS was independently associated with development of ACLF (HR, 1.613; 95% CI, 1.025-2.540) together with a MELD score above 15 (HR, 2.222; 95% CI, 1.400-3.528). Conclusion: LV-GLS is useful for identifying patients at risk of developing ACLF and a worse outcome after TIPS. Although validation is required, this tool might help to stratify risk in patients receiving TIPS.

[Acute Kidney Injury and Hepatorenal Syndrome]

Acute kidney injury (AKI) is common in patients with liver cirrhosis, occurring in 13-20% of patients hospitalized with decompensated cirrhosis, and is significantly associated with the prognosis. The development and progression of AKI is an independent predictive factor for mortality in these patients. If AKI develops, the renal function declines progressively even if AKI is improved later, the patients have a poorer prognosis compared to those who have not developed AKI. In addition, in patients without appropriate treatment or no improvement with the initial treatment, AKI often progress to hepatorenal syndrome (HRS), which is associated with significant morbidity and mortality. Therefore, early detection and appropriate management for the development of AKI is very important in these patients. Recently, there have been significant revisions in the diagnostic criteria and treatment of AKI and HRS; this manuscript reviews these changes.

Gut-Liver Axis Links Portal Hypertension to Acute-on-Chronic Liver Failure

Acute-on-chronic liver failure (ACLF) is considered a distinct syndrome in patients with liver disease, with systemic inflammation playing a central role. Portal hypertension (PHT) is also aggravated by inflammation and may subsequently impact the course of ACLF. PHT is more than just an increase in portal pressure in the portal venous system; it aggravates the course of liver disease and, thus, also facilitates the development of acute decompensation and ACLF. A critical mechanistic link between PHT and ACLF might be the gut-liver axis, which is discussed in this review.

Terlipressin in the treatment of hepatorenal syndrome: A systematic review and meta-analysis

BACKGROUND

Hepatorenal syndrome is a fatal complication of advanced cirrhosis. Terlipressin is the most widely used treatment method, however, the therapy effects remain inconsonant. We aim to systematically assess the safety and efficacy of terlipressin for hepatorenal syndrome.

METHODS

We conducted a systematic review and meta-analysis. Randomized controlled trials involving terlipressin for hepatorenal syndrome were included in a systematic literature search. Two authors independently assessed the studies for inclusion and extracted the data. A meta-analysis was conducted to estimate the safety and efficacy of terlipressin for hepatorenal syndrome.

RESULTS

A total of 18 randomized controlled trials including 1011 patients were included. Hepatorenal syndrome reverse rate was 42.0% in the terlipressin group and 26.2% in the non-terlipressin group. Terlipressin had greater hepatorenal syndrome reverse rate and renal function improvement rate than placebo and octreotide in the management of HRS. Comparing to norepinephrine, terlipressin had similar efficacy, but with more adverse events. No significant difference of the efficacy was found between terlipressin and dopamine treatment. The subgroup analysis for type 1 HRS had the above same results, except that the adverse events were not significant different between norepinephrine group and terlipressin group.

CONCLUSIONS

Terlipressin was superior to placebo and octreotide for reversal of hepatorenal syndrome and improving renal function, but it had no superiority comparing to norepinephrine.

Development of an automated phenotyping algorithm for hepatorenal syndrome

OBJECTIVE

Hepatorenal Syndrome (HRS) is a devastating form of acute kidney injury (AKI) in advanced liver disease patients with high morbidity and mortality, but phenotyping algorithms have not yet been developed using large electronic health record (EHR) databases. We evaluated and compared multiple phenotyping methods to achieve an accurate algorithm for HRS identification.

MATERIALS AND METHODS

A national retrospective cohort of patients with cirrhosis and AKI admitted to 124 Veterans Affairs hospitals was assembled from electronic health record data collected from 2005 to 2013. AKI was defined by the Kidney Disease: Improving Global Outcomes criteria. Five hundred and four hospitalizations were selected for manual chart review and served as the gold standard. Electronic Health Record based predictors were identified using structured and free text clinical data, subjected through NLP from the clinical Text Analysis Knowledge Extraction System. We explored several dimension reduction techniques for the NLP data, including newer high-throughput phenotyping and word embedding methods, and ascertained their effectiveness in identifying the phenotype without structured predictor variables. With the combined structured and NLP variables, we analyzed five phenotyping algorithms: penalized logistic regression, naïve Bayes, support vector machines, random forest, and gradient boosting. Calibration and discrimination metrics were calculated using 100 bootstrap iterations. In the final model, we report odds ratios and 95% confidence intervals.

RESULTS

The area under the receiver operating characteristic curve (AUC) for the different models ranged from 0.73 to 0.93; with penalized logistic regression having the best discriminatory performance. Calibration for logistic regression was modest, but gradient boosting and support vector machines were superior. NLP identified 6985 variables; a priori variable selection performed similarly to dimensionality reduction using high-throughput phenotyping and semantic similarity informed clustering (AUC of 0.81 - 0.82).

CONCLUSION

This study demonstrated improved phenotyping of a challenging AKI etiology, HRS, over ICD-9 coding. We also compared performance among multiple approaches to EHR-derived phenotyping, and found similar results between methods. Lastly, we showed that automated NLP dimension reduction is viable for acute illness.

Interfering RNA against PKC-α inhibits TNF-α-induced IP3R1 expression and improves glomerular filtration rate in rats with fulminant hepatic failure

We have reported that tumor necrosis factor-α (TNF-α) is critical for reduction of glomerular filtration rate (GFR) in rats with fulminant hepatic failure (FHF). The present study aims to evaluate the underlying mechanisms of decreased GFR during acute hepatic failure. Rats with FHF induced by d-galactosamine plus lipopolysaccharide (GalN/LPS) were injected intravenously with recombinant lentivirus harboring short hairpin RNA against the protein kinase C-α ( PKC-α) gene (Lenti-shRNA-PKC-α). GFR, serum levels of aminotransferases, creatinine, urea nitrogen, potassium, sodium, chloride, TNF-α, and endothelin-1 (ET-1), as well as type 1 inositol 1,4,5-trisphosphate receptor (IP₃R1) expression in renal tissue were assessed. The effects of PKC-α silencing on TNF-α-induced IP₃R1, specificity protein 1 (SP-1), and c-Jun NH₂-terminal kinase (JNK) expression, as well as cytosolic calcium content were determined in glomerular mesangial cell (GMCs) with RNAi against PKC-α. Renal IP₃R1 overexpression was abrogated by pre-treatment with Lenti-shRNA-PKC-α. The PKC-α silence significantly improved the compromised GFR, reduced Cr levels, and reversed the decrease in glomerular inulin space and the increase in glomerular calcium content in GalN/LPS-exposed rats. TNF-α treatment increased expression of PKC-α, IP₃R1, specificity protein 1 (SP-1), JNK, and p-JNK in GMCs and increased Ca^{2 +} release and binding activity of SP-1 to the IP₃R1 promoter. These effects were blocked by transfection of siRNA against the PKC-α gene, and the PKC-α gene silence also restored cytosolic Ca²⁺ concentration. RNAi targeting PKC-α inhibited TNF-α-induced IP₃R1 overexpression and in turn improved compromised GFR in the development of acute kidney injury during FHF in rats.

Increased myocardial contractility identifies patients with decompensated cirrhosis requiring liver transplantation

Late allocation of organs for transplant impairs post-liver transplantation (LT) survival. Cardiac dysfunction, especially diastolic and autonomic dysfunction, is frequent and plays an important role in the prognosis of patients with cirrhosis. However, the role of myocardial contractility is unexplored, and its prognostic value is controversially discussed. This study analyses the role of myocardial contractility assessed by speckle tracking echocardiography in LT allocation. In total, 168 patients with cirrhosis (training cohort, 111; validation cohort [VC], 57) awaiting LT in 2 centers were included in this retrospective study. Also, 51 patients from the training and all patients from the VC were transplanted, 36 patients of the training and 38 of the VC were alive at the end of follow-up, and 21 nontransplanted patients died. Contractility of the left ventricle (LV) increased with severity of the Child-Pugh score. Interestingly, higher LV contractility in the training cohort patients, especially in those with Child-Pugh C, was an independent predictor of reduced transplant-free survival. In male patients, the effects on survival of increased left and right ventricular myocardial contractility were more pronounced. Notably, competing risk analysis demonstrated that increased contractility is associated with earlier LT, which could be confirmed in the VC. Importantly, LV myocardial contractility had no impact on survival of patients not receiving LT or on post-LT survival. In conclusion, this study demonstrates for the first time that increased myocardial contractility in decompensated patients identifies patients who require LT earlier, but without increased post-LT mortality. Liver Transplantation 24 15-25 2018 AASLD.

Austrian consensus guidelines on the management and treatment of portal hypertension (Billroth III)

The Billroth III guidelines were developed during a consensus meeting of the Austrian Society of Gastroenterology and Hepatology (ÖGGH) and the Austrian Society of Interventional Radiology (ÖGIR) held on 18 February 2017 in Vienna. Based on international guidelines and considering recent landmark studies, the Billroth III recommendations aim to help physicians in guiding diagnostic and therapeutic strategies in patients with portal hypertension.

Cholemic nephropathy - Historical notes and novel perspectives

Acute kidney injury is common in patients with liver disease and associated with significant morbidity and mortality. Besides bacterial infections, fluid loss, and use of nephrotoxic drugs AKI in liver disease may be triggered by tubular toxicity of cholephiles. Cholemic nephropathy, also known as bile cast nephropathy, supposedly represents a widely underestimated but important cause of renal dysfunction in cholestasic or advanced liver diseases with jaundice. Cholemic nephropathy describes impaired renal function along with characteristic histomorphological changes consisting of intratubular cast formation and tubular epithelial cell injury directed towards distal nephron segments. The underlying pathophysiologic mechanisms are not entirely understood and clear defined diagnostic criteria are still missing. This review aims to summarize (i) the present knowledge on clinical and morphological characteristics of cholemic nephropathy, (ii) available preclinical models, (iii) potential pathomechanisms especially the potential role of bile acids, and (iv) future diagnostic and therapeutic strategies for cholemic nephropathy. This article is part of a Special Issue entitled: Cholangiocytes in Health and Disease edited by Jesus Banales, Marco Marzioni, Nicholas LaRusso and Peter Jansen.

Acute Kidney Injury in Cirrhosis: Baseline Serum Creatinine Predicts Patient Outcomes

OBJECTIVES

The International Ascites Club (IAC) recently defined Stage 1 acute kidney injury (AKI) for cirrhosis as an acute increase in serum creatinine (SCr) by ≥0.3 mg/dl or by ≥50% in <48 h from a stable value within 3 months. The baseline SCr may influence AKI risk and patient outcomes. The objective of this study is to determine in cirrhosis whether the baseline SCr has any effect on the in-hospital AKI course and patient survival.

METHODS

North American Consortium for the Study of End-Stage Liver Disease is a consortium of tertiary-care hepatology centers prospectively enroling non-elective cirrhotic inpatients. Patients with different baseline SCr levels (≤0.5, 0.51-1.0, 1.01-1.5, >1.5 mg/dl) were evaluated for the development of AKI, and compared for AKI outcomes and 30-day survival.

RESULTS

653 hospitalized cirrhotics (56.7±10years, 64% men, 30% with infection) were included. The incidence of AKI was 47% of enrolled patients. Patients with higher baseline SCr were more likely to develop AKI, with significantly higher delta and peak SCr (P<0.001) than the other groups, more likely to have a progressive AKI course (P<0.0001), associated with a significantly reduced 30-day survival (P<0.0001). Multivariate logistic regression showed that the delta SCr during an AKI episode to be the strongest factor impacting AKI outcomes and survival (P<0.001), with a delta SCr of 0.70 mg/dl having a 68% sensitivity and 80% specificity for predicting 30-day mortality.

CONCLUSIONS

Admitted cirrhotic patients with higher baseline SCr are at higher risk for in-hospital development of AKI, and more likely to have AKI progression with reduced survival. Therefore, such patients should be closely monitored and treated promptly for their AKI.

NorUrsodeoxycholic acid ameliorates cholemic nephropathy in bile duct ligated mice

BACKGROUND & AIMS

Severe cholestasis may cause cholemic nephropathy that can be modeled in common bile duct ligated (CBDL) mice. We aimed to explore the therapeutic efficacy and mechanisms of norursodeoxycholic acid (norUDCA) in cholemic nephropathy.

METHODS

In 8-week CBDL mice fed with norUDCA (prior or post CBDL) or chow we evaluated serum urea levels, urine cytology and urinary neutrophil gelatinase associated lipocalin (uNGAL), kidney and liver tissue quantification of fibrosis by hydroxyproline content and gene chip expression looking at key genes of inflammation and fibrosis. Moreover, we comprehensively analysed bile acid profiles in liver, kidney, serum and urine samples.

RESULTS

NorUDCA-fed CBDL mice had significantly lower serum urea and uNGAL levels and less severe cholemic nephropathy as demonstrated by normal urine cytology, significantly reduced tubulointerstitial nephritis, and renal fibrosis as compared to controls. NorUDCA underwent extensive metabolism to produce even more hydrophilic compounds that were significantly enriched in kidneys.

CONCLUSION

NorUDCA ameliorates cholemic nephropathy due to the formation of highly hydrophilic metabolites enriched in kidney. Consequently, norUDCA may represent a medical treatment for cholemic nephropathy.

LAY SUMMARY

The term cholemic nephropathy describes renal dysfunction together with characteristic morphological alterations of the kidney in obstructive cholestasis that can be mimicked by ligation of the common bile duct in mice. Feeding the hydrophilic bile acid norUDCA to bile duct ligated mice leads to a significant amelioration of the renal phenotype due to the formation of highly hydrophilic metabolites enriched in the kidney and may therefore represent a medical treatment for cholemic nephropathy.

Reversal of hepatorenal syndrome type 1 with terlipressin plus albumin vs. placebo plus albumin in a pooled analysis of the OT-0401 and REVERSE randomised clinical studies

BACKGROUND

The goal of hepatorenal syndrome type 1 (HRS-1) treatment is to improve renal function. Terlipressin, a synthetic vasopressin analogue, is a systemic vasoconstrictor used for the treatment of HRS-1, where it is available.

AIM

To compare the efficacy of terlipressin plus albumin vs. placebo plus albumin in patients with HRS-1.

METHODS

Pooled patient-level data from two large phase 3, randomised, placebo-controlled studies were analysed for HRS reversal [serum creatinine (SCr) value ≤133 μmol/L], 90-day survival, need for renal replacement therapy and predictors of HRS reversal. Patients received intravenous terlipressin 1-2 mg every 6 hours plus albumin or placebo plus albumin up to 14 days.

RESULTS

The pooled analysis comprised 308 patients (terlipressin: n = 153; placebo: n = 155). HRS reversal was significantly more frequent with terlipressin vs. placebo (27% vs. 14%; P = 0.004). Terlipressin was associated with a more significant improvement in renal function from baseline until end of treatment, with a mean between-group difference in SCr concentration of -53.0 μmol/L (P < 0.0001). Lower SCr, lower mean arterial pressure and lower total bilirubin and absence of known precipitating factors for HRS were independent predictors of HRS reversal and longer survival in terlipressin-treated patients.

CONCLUSIONS

Terlipressin plus albumin resulted in a significantly higher rate of HRS reversal vs. albumin alone in patients with HRS-1. Terlipressin treatment is associated with improved renal function. (ClinicalTrials.gov identifier: OT-0401, NCT00089570; REVERSE, NCT01143246).

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.

Terlipressin Improves Renal Function and Reverses Hepatorenal Syndrome in Patients With Systemic Inflammatory Response Syndrome

BACKGROUND & AIMS

Patients with systemic inflammatory response syndrome (SIRS) along with decompensated cirrhosis and renal dysfunction have a poor prognosis and a lower response to treatment. We evaluated the effect of SIRS on the response of hepatorenal syndrome type 1 (HRS-1) to terlipressin.

METHODS

We performed a retrospective study of data from a trial of the effects of terlipressin (1 mg every 6 hours or placebo with concomitant albumin) in 198 patients with HRS-1, performed at 50 investigational sites in the United States and 2 in Canada from October 2010 through February 2013. We identified patients with 2 or more criteria for SIRS, without untreated infections (28 received terlipressin and 30 received placebo), and patients with less than 2 criteria for SIRS (control subjects). Primary endpoints included HRS reversal (a decrease in serum level of creatinine to ≤1.5 mg/dL), confirmed HRS reversal (defined as 2 serum creatinine levels ≤1.5 mg/dL, ≥ 48 hours apart), and survival for 90 days after treatment.

RESULTS

Baseline characteristics were similar between groups, apart from slightly higher white blood cell counts and heart rates, and slightly lower serum levels of bicarbonate in patients with SIRS versus without SIRS. HRS was reversed in 42.9% of patients who received terlipressin with SIRS (12/28) versus 6.7% of patients who received placebo (2/30) (P = .0018); confirmed HRS reversal occurred in 32.1% of patients who received terlipressin with SIRS (9/28) versus 3.3% who received placebo (1/30) (P = .0048). A larger proportion of patients with SIRS who received terlipressin survived for 90 days without a transplant (13/28; 46.4%) than patients with SIRS who received placebo (7/30; 23.3%) (P = .076).

CONCLUSIONS

In an analysis of data from a placebo-controlled study, we found that terlipressin improved renal function and reversed HRS in a higher proportion of patients with HRS-1 and SIRS than patients who received albumin plus placebo. ClincialTrials.gov, number NCT 01143246.

Emergency TIPS in a Child-Pugh B patient: When does the window of opportunity open and close?

Transjugular intrahepatic portosystemic shunt (TIPS) is used to treat complications of cirrhosis such as variceal bleeding and refractory ascites, but it also bears the risk of liver failure, overt hepatic encephalopathy (HE) and cardiac decompensation. Variceal bleeding may be controlled using endoscopic and medical treatment in patients with compensated cirrhosis; in decompensated patients, however, TIPS improves survival. Therefore, an early TIPS (within 72h or if later, still early after bleeding) might improve the survival of patients by preventing an inflammatory response and bacterial translocation. Both these processes mediate an impaired immunological and hemodynamic response, thereby facilitating the development of acute-on-chronic liver failure (ACLF) and/or death. Similarly, in patients with refractory ascites, TIPS should be used early in treatment to prevent acute kidney injury (AKI) and hepatorenal syndrome (HRS) after precipitating events induced by complications of portal hypertension. Whether TIPS and/or embolization should be used to treat portal vein thrombosis and spontaneous shunts is still a matter of debate and should be further investigated. In summary, the careful selection of patients for TIPS is crucial. New biomarkers, especially those evaluating systemic inflammation and bacterial translocation, might improve the predictive value of established clinical parameters such as bilirubin and overt HE. However, a significant amount of further research must be carried out.

Acute kidney injury in liver cirrhosis: new definition and application

The traditional diagnostic criteria of renal dysfunction in cirrhosis are a 50% increase in serum creatinine (SCr) with a final value above 1.5 mg/dL. This means that patients with milder degrees of renal dysfunction are not being diagnosed, and therefore not offered timely treatment. The International Ascites Club in 2015 adapted the term acute kidney injury (AKI) to represent acute renal dysfunction in cirrhosis, and defined it by an increase in SCr of 0.3 mg/dL (26.4 µmoL/L) in <48 hours, or a 50% increase in SCr from a baseline within ≤3 months. The severity of AKI is described by stages, with stage 1 represented by these minimal changes, while stages 2 and 3 AKI by 2-fold and 3-fold increases in SCr respectively. Hepatorenal syndrome (HRS), renamed AKI-HRS, is defined by stage 2 or 3 AKI that fulfils all other diagnostic criteria of HRS. Various studies in the past few years have indicated that these new diagnostic criteria are valid in the prediction of prognosis for patients with cirrhosis and AKI. The future in AKI diagnosis may include further refinements such as inclusion of biomarkers that can identify susceptibility for AKI, differentiating the various prototypes of AKI, or track its progression.

Protecting the Kidney in Liver Transplant Candidates: Practice-Based Recommendations From the American Society of Transplantation Liver and Intestine Community of Practice

Acute kidney injury (AKI) and chronic kidney disease (CKD) are common in patients awaiting liver transplantation, and both have a marked impact on the perioperative and long-term morbidity and mortality of liver transplant recipients. Consequently, we reviewed the epidemiology of AKI and CKD in patients with end-stage liver disease, highlighted strategies to prevent and manage AKI, evaluated the changing liver transplant waiting list's impact on kidney function, delineated important considerations in simultaneous liver-kidney transplant selection, and projected possible future transplant policy changes and outcomes. This review was assembled by experts in the field and endorsed by the American Society of Transplantation Liver and Intestinal Community of Practice and Board of Directors and provides practice-based recommendations for preservation of kidney function in patients with end-stage liver disease.

Association of eNOS Gene Polymorphisms G894T and T-786C with Risk of Hepatorenal Syndrome

Background. There are no studies investigating the relationship between endothelial nitric oxide synthase (eNOS) gene polymorphisms and hepatorenal syndrome (HRS). Aim. The purpose of this study is to elucidate whether eNOS gene polymorphisms (G894T and T-786C) play a role in the development of type-2 HRS. Methods. This study was carried out in a group of 92 patients with cirrhosis (44 patients with type-2 HRS and 48 without HRS) and 50 healthy controls. Polymorphisms were determined by polymerase chain reaction (PCR) and melting curve analysis. Results. We did not find any significant difference in allele and genotype distributions of the eNOS -T-786C polymorphism among the groups (p = 0.440). However, the frequency of GT (40.9%) and TT (13.6%) genotypes and mutant allele T (34.1%) for the eNOS G894T polymorphism were significantly higher (p < 0.001 and p < 0.001, resp.) in the HRS group than in both the stable cirrhosis (14.6%, 4.2%, and 11.5%, resp.) and the control (22.0%, 2.0%, and 13.0%, resp.) groups. Conclusion. The occurrence of mutant genotypes (GT/TT) and mutant allele T in eNOS -G894T polymorphisms should be considered as a potential risk factor in cirrhotic patients with HRS.

Terlipressin Plus Albumin Is More Effective Than Albumin Alone in Improving Renal Function in Patients With Cirrhosis and Hepatorenal Syndrome Type 1

BACKGROUND & AIMS

Hepatorenal syndrome type 1 (HRS-1) in patients with cirrhosis and ascites is a functional, potentially reversible, form of acute kidney injury characterized by rapid (<2 wk) and progressive deterioration of renal function. Terlipressin is a synthetic vasopressin analogue that acts, via vascular vasopressin V1 receptors, as a systemic vasoconstrictor. We performed a phase 3 study to evaluate the efficacy and safety of intravenous terlipressin plus albumin vs placebo plus albumin in patients with HRS-1.

METHODS

Adult patients with cirrhosis, ascites, and HRS-1 (based on the 2007 International Club of Ascites criteria of rapidly deteriorating renal function) were assigned randomly to groups given intravenous terlipressin (1 mg, n = 97) or placebo (n = 99) every 6 hours with concomitant albumin. Treatment continued through day 14 unless the following occurred: confirmed HRS reversal (CHRSR, defined as 2 serum creatinine [SCr] values ≤1.5 mg/dL, at least 40 hours apart, on treatment without renal replacement therapy or liver transplantation) or SCr at or above baseline on day 4. The primary end point was the percentage of patients with confirmed CHRSR. Secondary end points included the incidence of HRS reversal (defined as at least 1 SCr value ≤1.5 mg/dL while on treatment), transplant-free survival, and overall survival. The study was performed at 50 investigational sites in the United States and 2 in Canada, from October 2010 through February 2013.

RESULTS

Baseline demographic/clinical characteristics were similar between groups. CHRSR was observed in 19 of 97 patients (19.6%) receiving terlipressin vs 13 of 99 patients (13.1%) receiving placebo (P = .22). HRS reversal was achieved in 23 of 97 (23.7%) patients receiving terlipressin vs 15 of 99 (15.2%) receiving placebo (P = .13). SCr decreased by 1.1 mg/dL in patients receiving terlipressin and by only 0.6 mg/dL in patients receiving placebo (P < .001). Decreases in SCr and survival were correlated (r(2) = .882; P < .001). Transplant-free and overall survival were similar between groups. A significantly greater proportion of patients with CHRSR who received terlipressin survived until day 90 than patients who did not have CHRSR after receiving terlipressin (P < .001); this difference was not observed in patients who did vs did not have CHRSR after receiving placebo (P = .28). There were similar numbers of adverse events in each group, but patients in the terlipressin group had more ischemic events.

CONCLUSIONS

Terlipressin plus albumin was associated with greater improvement in renal function vs albumin alone in patients with cirrhosis and HRS-1. Patients had similar rates of HRS reversal with terlipressin as they did with albumin. ClinicalTrials.gov no: NCT01143246.

Pretransplant Type 2 Hepatorenal Syndrome Is Associated With Persistently Impaired Renal Function After Liver Transplantation

BACKGROUND

Type 2 hepatorenal syndrome (HRS2) is a functional renal impairment complicating end-stage liver disease. Although it is reversible after liver transplantation, long-term posttransplant outcomes in HRS2 patients remain ill-defined.

METHODS

Retrospective, matched case-control (1:2) study of all adult HRS2 patients transplanted in our institution between 2000 and 2012. The HRS2 patients were identified from our electronic transplant database, and matched with controls for the following variables: age, sex, etiology, diabetes mellitus, and year of transplant.

RESULTS

Forty-two HRS2 patients were compared to 83 controls. At the time of transplant, HRS2 patients had an estimated glomerular filtration rate of 41 ± 1 mL/min per 1.73 m. The HRS2 patients had greater intraoperative packed red blood cell transfusion (P = 0.002), and longer intensive care unit (P = 0.01) as well as total hospital length of stay (P = 0.03). Reversal of HRS2 occurred in 88.1% patients, 5.7 ± 0.5 days after transplantation. Although HRS2 patients had lower initial exposure to calcineurin inhibitors, a greater proportion of HRS2 patients had chronic kidney disease stage 3 (CKD3) at 3 (53.8% vs 28.4%; P = 0.007) and 12 months (59.5% vs 38.2%; P = 0.03) compared to controls. One-year survival was similar between the 2 groups (log-rank P = 0.82). On multivariate analysis, pretransplant HRS2 was associated with CKD3 at 3 (odds ratio, 3.73; 95% confidence interval, 1.54-9.03; P = 0.004) and 12 months (odds ratio, 3.23; 95% confidence interval, 1.37-7.64; P = 0.007) after transplantation.

CONCLUSIONS

Liver transplantation reverses HRS2 in the majority of patients with survival outcomes comparable to matched controls, despite longer stays in intensive care unit and in hospital. Pretransplant HRS2 is associated with early posttransplant CKD3, despite calcineurin-inhibitor minimization.

Renal Impairment with Sublethal Tubular Cell Injury in a Chronic Liver Disease Mouse Model

The pathogenesis of renal impairment in chronic liver diseases (CLDs) has been primarily studied in the advanced stages of hepatic injury. Meanwhile, the pathology of renal impairment in the early phase of CLDs is poorly understood, and animal models to elucidate its mechanisms are needed. Thus, we investigated whether an existing mouse model of CLD induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) shows renal impairment in the early phase. Renal injury markers, renal histology (including immunohistochemistry for tubular injury markers and transmission electron microscopy), autophagy, and oxidative stress were studied longitudinally in DDC- and standard diet-fed BALB/c mice. Slight but significant renal dysfunction was evident in DDC-fed mice from the early phase. Meanwhile, histological examinations of the kidneys with routine light microscopy did not show definitive morphological findings, and electron microscopic analyses were required to detect limited injuries such as loss of brush border microvilli and mitochondrial deformities. Limited injuries have been recently designated as sublethal tubular cell injury. As humans with renal impairment, either with or without CLD, often show almost normal tubules, sublethal injury has been of particular interest. In this study, the injuries were associated with mitochondrial aberrations and oxidative stress, a possible mechanism for sublethal injury. Intriguingly, two defense mechanisms were associated with this injury that prevent it from progressing to apparent cell death: autophagy and single-cell extrusion with regeneration. Furthermore, the renal impairment of this model progressed to chronic kidney disease with interstitial fibrosis after long-term DDC feeding. These findings indicated that DDC induces renal impairment with sublethal tubular cell injury from the early phase, leading to chronic kidney disease. Importantly, this CLD mouse model could be useful for studying the pathophysiological mechanisms of sublethal tubular cell injury.