Evaluation of acute kidney injury and its response to terlipressin in patients with acute-on-chronic liver failure

The Kidney and Extracorporeal Therapies in Acute-on-Chronic Liver Failure: What the Nephrologist Needs to Know

In this review, we discuss the pathophysiology and management of acute kidney injury (AKI) in the setting of acute-on-chronic liver failure (ACLF). ACLF is characterised by the occurrence of acute hepatic and/or extrahepatic organ failure, induced by immune dysregulation and systemic inflammation in patients with chronic liver disease. Kidney involvement is common, with AKI occurring in 30% to > 95% of ACLF patients, depending on the definition used. Since there is a lack of kidney biopsy data in these patients, the underlying pathophysiological basis of AKI remains incompletely understood, and systemic inflammation is believed to be the primary driver of organ injury. The management of AKI has been largely extrapolated from studies in decompensated cirrhosis, and there is little data specifically in the ACLF setting. However, available evidence suggests that structural kidney injury is more common in ACLF than in decompensated CLD, and therefore, AKI in ACLF is less likely to respond to volume repletion and vasopressors. Treatment options remain limited for those who are non-responsive to intravenous fluids and vasopressors. Liver transplantation (LT), with or without kidney transplantation, is the definitive treatment for these patients. At present, extracorporeal therapies such as therapeutic plasma exchange and kidney replacement therapies play a supportive role in ACLF as a bridge to LT; however, the optimal timing and dosing remain unclear. While theoretically, extracorporeal therapies have the potential to reverse or halt progression of organ damage in ACLF, there is limited evidence currently.

Mortality of Acute Kidney Injury in Cirrhosis: A Systematic Review and Meta-Analysis of Over 5 Million Patients Across Different Clinical Settings

BACKGROUND

Acute kidney injury (AKI) represents a commonly seen condition in the natural course of cirrhosis associated with unfavourable outcomes.

AIMS

To evaluate and compare the pooled mortality rates of patients with cirrhosis, with versus without AKI, across different clinical settings and diagnostic criteria.

METHODS

A systematic search of several databases was performed up to Oct 2023. Meta-analysis was performed using a generalised linear mixed model with a random effects model for all calculations.

RESULTS

A total of 59 studies comparing patients with cirrhosis, with and without AKI, were included in the meta-analysis, encompassing 1,153,193 individuals with AKI and 4,630,814 without AKI. AKI development predisposed to significantly higher short (in-hospital and 30-days)-, intermediate (90-days)- and long (1-year)-term mortality rates in both inpatients and outpatients. Remarkably, patients with AKI admitted to intensive care unit (ICU) or diagnosed with acute-on-chronic liver failure (ACLF) experienced the higher short-term mortality rates, reaching 76% [95% confidence interval (CI): 73%-79%] and 54% (95%CI: 33%-73%), respectively. AKI staging correlated with mortality risk, with higher stages indicating higher mortality rates, while the timing of AKI development, whether community-acquired or hospital-acquired, plays a crucial role in patient prognosis, with distinct mortality patterns observed in each group. The selection of diagnostic criteria for AKI may also impact its association with the short-term mortality risk.

CONCLUSIONS

AKI substantially affects the prognosis of patients with cirrhosis, especially those in ICU and/or with ACLF. Prognosis is also greatly influenced by the AKI stage, timing of onset and diagnostic criteria.

AARC score and urine NGAL predict terlipressin non-response and mortality in patients with acute-on-chronic liver failure

BACKGROUND AND AIM

Acute-on-chronic liver failure (ACLF) patients with hepatorenal syndrome (HRS-AKI) have limited response to vasoconstrictors and worse outcomes, requiring biomarkers for early detection.

METHODS

In a prospective cohort of ACLF patients (n = 240), urine NGAL was performed in patients with the clinical diagnosis of HRS-AKI, while in a subset of patients (n = 30), a complete panel of 17 urinary biomarkers was assessed for identifying terlipressin non-response (T-NR).

RESULTS

ACLF patients with HRS-AKI, aged 45.84 ± 10.6 years, 91.2% males, 74.2% with alcohol etiology, mean urine NGAL of 1541.66 ± 1684.69 ng/ml, AARC score 10.19 ± 1.86, 155 (64.5%) had T-NR at day 4. T-NR was maximal for AARC grade 3 and was associated with a higher need of dialysis (50.3% vs 5.9%; OR 16.21, 6.23-42.19) and 28-day mortality (49.0% vs. 17.9%; HR 3.42, 1.96-5.95). AARC grade 3 (OR 38.21, 2.93-497.74), (HR 5.10, 1.19-21.84) and urine NGAL (OR 11.53, 5.66-23.49; AUROC 0.97, NGAL > 900 ng/ml) (HR 1.23, 1.02-1.49) were independent predictors of T-NR and 28-day mortality, respectively. It was interesting to observe a significant elevation in renal injury and a decrease in the repair markers in T-NR (p < 0.05).

CONCLUSION

Almost 60% of patients with ACLF and HRS-AKI experience non-response to terlipressin which predicts higher mortality and need for dialysis. High NGAL above 900 ng/ml predicts T-NR with 100% specificity for T-NR. ACLF patients with HRS, with AARC grade 3 and high NGAL have a high likelihood of T-NR and should be considered for alternative therapeutic modalities.

Acute-on-chronic liver failure in metabolic dysfunction-associated fatty liver disease patients: a disease multiplier

Acute-on-chronic liver failure (ACLF) is a syndrome of liver failure due to an acute hepatic insult leading to liver failure with or without extra-hepatic organ failure in a patient of chronic liver disease (CLD) with or without cirrhosis presenting for the first time. The definition is still with controversy; hence, homogeneity and clarity of the case is an unmet need. There is a paradigm shift noted as far as the etiology of CLD is concerned with rise in metabolic dysfunction-associated fatty liver disease (MAFLD) and ethanol as the dominant cause even in developing countries. MAFLD is the change in nomenclature from NAFLD to justify the metabolic derangement in these group of patients. The shift from an exclusion-based criteria to one that has evolved to a diagnosis that requires positive criteria has profound significance. Clearly there is a difference in terms of its prevalence, disease progression, and liver-related events, as well as management of metabolic risk factors and MAFLD itself which requires further understanding. In tandem with the global rise in MAFLD, the incidence of MAFLD-ACLF is increasing. Excessive alcohol consumption causes metabolic and toxic injury to the liver resulting in nearly similar pathway of fatty liver, hepatitis, and cirrhosis. The interaction of MAFLD as an additional underlying chronic liver injury in ACLF patients is complex due to the presence of metabolic risk factors that are unique to MAFLD. There is lack of clarity on how MAFLD affects the clinical course of ACLF due to scarcity of this specific data. This narrative review aims to understand the unique effects, consequences, and management of MAFLD as the chronic liver injury component in ACLF.

Incidence and risk factors of acute kidney injury in cirrhosis: a systematic review and meta-analysis of 5,202,232 outpatients, inpatients, and ICU-admitted patients

INTRODUCTION

Acute kidney injury (AKI) is a commonly seen condition in the natural course of cirrhosis. The aim of this study was to evaluate the pooled incidence and risk factors of AKI in different clinical stages and situations in patients with cirrhosis.

METHODS

Search was conducted on 13 December 2023 across MEDLINE (PubMed), Embase, and Cochrane databases. Meta-analysis was performed using a generalized linear mixed model.

RESULTS

In total, 73 studies with 5,202,232 patients were finally enrolled in the meta-analysis. AKI commonly occurs among hospitalized cirrhotics experiencing any decompensation event (29%) as well as among stable outpatients (28%) throughout a 1-year follow-up period. On admission, patients with infection or sepsis/septic shock had the highest AKI rate (47%), followed by those with hepatic encephalopathy (41%). Furthermore, the severity of liver disease proved to be a substantial driver for AKI development, while patients at intensive care unit had the greatest AKI incidence (61%).

CONCLUSIONS

Both hospitalized patients and stable outpatients with cirrhosis exhibited an elevated susceptibility to AKI. Patients at intensive care unit and those with severe liver disease, infection, sepsis/septic shock, hepatic encephalopathy, or acute on chronic liver failure upon admission are at higher risk for AKI.

TRIAL REGISTRATION

PROSPERO, registered 09/12/23, CRD42023487736.

APASL clinical practice guidelines on the management of acute kidney injury in acute-on-chronic liver failure

Acute-on-chronic liver failure (ACLF) is a syndrome that is characterized by the rapid development of organ failures predisposing these patients to a high risk of short-term early death. The main causes of organ failure in these patients are bacterial infections and systemic inflammation, both of which can be severe. For the majority of these patients, a prompt liver transplant is still the only effective course of treatment. Kidneys are one of the most frequent extrahepatic organs that are affected in patients with ACLF, since acute kidney injury (AKI) is reported in 22.8-34% of patients with ACLF. Approach and management of kidney injury could improve overall outcomes in these patients. Importantly, patients with ACLF more frequently have stage 3 AKI with a low rate of response to the current treatment modalities. The objective of the present position paper is to critically review and analyze the published data on AKI in ACLF, evolve a consensus, and provide recommendations for early diagnosis, pathophysiology, prevention, and management of AKI in patients with ACLF. In the absence of direct evidence, we propose expert opinions for guidance in managing AKI in this very challenging group of patients and focus on areas of future research. This consensus will be of major importance to all hepatologists, liver transplant surgeons, and intensivists across the globe.

Early Versus Standard Initiation of Terlipressin for Acute Kidney Injury in ACLF: A Randomized Controlled Trial (eTerli Study)

BACKGROUND AND AIMS

Terlipressin infusion is effective in hepatorenal syndrome (HRS-AKI). However, its efficacy for HRS-AKI resolution in acute-on-chronic liver failure (ACLF) patients has been suboptimal. Progression of AKI is rapid in ACLF. We investigated whether early initiation of terlipressin(eTerli) can improve response rates.

METHODS

Consecutive ACLF patients with stage II/III AKI despite albumin resuscitation (40 g) were randomized to receive terlipressin at 2 mg/24 h plus albumin at 12 h (ET, n = 35) or at 48 h as standard therapy (ST, n = 35). (June 22, 2020 to June 10, 2022). The primary end-point was AKI reversal by day7.

RESULTS

Baseline parameters including AKI stage and ACLF-AARC scores in two arms were comparable. Full AKI response at day 7 was higher in ET [24/35 (68.6%)] than ST arm [11/35 (31.4%; P 0.03]. Day3 AKI response was also higher in ET arm [11/35 (31.4%) vs. 4/35 (11.4%), P 0.04]. Using ST compared to ET [HR 4.3; P 0.026] and day 3 serum creatinine > 1.6 mg/dl [HR 9.1; AUROC-0.866; P < 0.001] predicted HRS-AKI non-response at day 7. ET patients showed greater improvement in ACLF grade, mean arterial pressure, and urine output at day 3, and required lower albumin within 7 days than ET arm (149.1 ± 41.8 g vs. 177.5 ± 40.3 g, P 0.006) and had lower 28-day mortality: 40% vs. 65.7%, P 0.031]. Early use of terlipressin than ST [HR 2.079; P 0.038], baseline HE [HR 2.929; P 0.018], and AKI persistence at day 3 [HR 1.369; P 0.011] predicted 28-day mortality. Fifteen (21.4%) patients had treatment related adverse effects, none was life threatening.

CONCLUSION

In ACLF patients, early initiation of terlipressin for AKI persisting after 12 h of volume expansion with albumin helps in reduced short-term mortality and early AKI reversal with regression of ACLF stage. These results indicate need for change in current practice for terlipressin usage in HRS-AKI.

The Clinical Spectrum and Manifestations of Acute-on-Chronic Liver Failure

Acute-on-chronic liver failure (ACLF) is characterized by abrupt decompensation in a patient with chronic liver disease with extrahepatic organ dysfunction and is implicated in an increased risk of mortality. ACLF may be present in approximately 20% to 40% of hospitalized cirrhosis. There are several diagnostic scoring systems for ACLF; one defined by the North American Consortium for Study of End-stage Liver Disease is the presence of acutely decompensated cirrhosis complicated by failure of two or more organ systems: circulatory, renal, neurological, coagulopathy, and/or pulmonary.

Terlipressin in the management of adults with hepatorenal syndrome-acute kidney injury (HRS-AKI)

INTRODUCTION

Kidney is the most common extra-hepatic organ involved in patients with advanced liver cirrhosis and acute-on-chronic liver failure. Hepatorenal syndrome-acute kidney injury (HRS-AKI) accounts for most hospitalizations, and liver transplantation (LT) remains the ultimate and long-term treatment in such patients. However, HRS-AKI, being a functional renal failure, has a fair chance of reversal, and as such, patients who achieve reversal of HRS-AKI have better outcomes post-LT.

AREAS COVERED

In this review, we discuss the pharmacokinetics, pharmacodynamics and evidence to support the use of terlipressin in HRS-AKI while we also address predictors of response and the associated adverse events. Further, we discuss the role of terlipressin in the context of LT.

EXPERT OPINION

The recommended treatment for HRS-AKI reversal includes a vasoconstrictor in addition to volume expansion with albumin. The three vasoconstrictor regimens generally used to treat HRS-AKI include octreotide plus midodrine, noradrenaline, and terlipressin. Of these, terlipressin is a widely used drug and has been recently approved by US Food and Drug Administration (USFDA) for HRS-AKI. Terlipressin is the most effective drug for HRS-AKI reversal and is associated with a decreased need for renal replacement therapy pre- and post-transplant. Furthermore, terlipressin responders have improved transplant-free and post-transplant survival.

Acute kidney injury in patients with acute-on-chronic liver failure: clinical significance and management

Acute-on-chronic-liver failure (ACLF) refers to a phenomenon in which patients with chronic liver disease develop multiple organ failure due to acute exacerbation of underlying liver disease. More than 10 definitions of ACLF are extant around the world, and there is lack of consensus on whether extrahepatic organ failure is a main component or a consequence of ACLF. Asian and European consortiums have their own definitions of ACLF. The Asian Pacific Association for the Study of the Liver ACLF Research Consortium does not consider kidney failure as a diagnostic criterion for ACLF. Meanwhile, the European Association for the Study of the Liver Chronic Liver Failure and the North American Consortium for the Study of End-stage Liver Disease do consider kidney failure as an important factor in diagnosing and assessing the severity of ACLF. When kidney failure occurs in ACLF patients, treatment varies depending on the presence and stage of acute kidney injury (AKI). In general, the diagnosis of AKI in cirrhotic patients is based on the International Club of Ascites criteria: an increase of 0.3 mg/dL or more within 48 hours or a serum creatinine increase of 50% or more within one week. This study underscores the importance of kidney failure or AKI in patients with ACLF by reviewing its pathophysiology, prevention methods, and treatment approaches.

Impact of acute kidney injury on the risk of mortality in patients with cirrhosis: a systematic review and meta-analysis

Objective

To compare the risk of mortality in patients with cirrhosis with and without the associated acute kidney injury (AKI).

Methods

We performed a systematic search in the PubMed, Embase, and Scopus databases for observational studies that were done on patients with cirrhosis. Eligible studies reported AKI in patients with cirrhosis and compared mortality among patients with and without AKI. We used a random-effects model, using STATA version 16.0, for deriving pooled effect sizes that were reported as odds ratio (OR) with 95% confidence intervals (CIs).

Results

Thirty-two studies were included. In patients with cirrhosis, AKI was significantly associated with higher in-hospital mortality (OR 5.92), and mortality at 30 days (OR 4.78), 90 days (OR 4.34), and at 1 year follow-up (OR 4.82) compared to patients without AKI.

Conclusions

AKI is associated with an increased risk of mortality in patients with cirrhosis. Careful monitoring to identify the development of AKI and early prompt management is necessary.

Natural history, spectrum and outcome of stage 3 AKI in patients with acute-on-chronic liver failure

BACKGROUND AND AIM

There is limited data on natural course and interventions in stage-3 acute kidney injury (AKI-3) in patients with acute-on-chronic liver failure (ACLF). We studied the factors of AKI-3 reversal and outcomes of dialysis in ACLF patients.

METHODS

Consecutive patients with ACLF were prospectively enrolled (n = 1022) and variables determining AKI and its outcomes were analysed.

RESULTS

At 1 month, 337 (33%) patients had AKI-3, of which, 131 had AKI-3 at enrolment and 206 developed AKI-3 during hospital stay. Of patients with AKI-3 at enrolment, 18% showed terlipressin response, 21% had AKI resolution and 59% required dialysis. High MELD (≥35) (model 1), serum bilirubin (≥23 mg/dL) (model 2) and AARC score (≥11) (model 3) were independent risk factors for dialysis. Dialysis was associated with worse survival in all AKI patients but improved outcomes in patients with AKI-3 (p = .022, HR 0.69 [0.50-0.95]). Post-mortem kidney biopsies (n = 61) revealed cholemic nephropathy (CN) in 54%, acute tubular necrosis (ATN) in 31%, and a combination (CN and ATN) in 15%. Serum bilirubin was significantly higher in patients with CN, CN and ATN compared with ATN respectively ([30.8 ± 12.2] vs. [26.7 ± 12.0] vs. [18.5 ± 9.8]; p = .002).

CONCLUSION

AKI-3 rapidly increases from 13% to 33% within 30 days in ACLF patients. Histopathological data suggested cholemic nephropathy as the predominant cause which correlated with high bilirubin levels. AKI-3 resolves in only one in five patients. Patients with AARC grade 3 and MELD >35 demand need for early dialysis in AKI-3 for improved outcomes.

Urinary Neutrophil Gelatinase-Associated Lipocalin Can Predict the Efficacy of Volume Expansion Therapy in Patients With Hepatitis B Cirrhosis and AKI

Backgrounds: Kidney biomarkers in urine appear to be useful in differential diagnosis between acute tubular necrosis and other types of acute kidney injury (AKI) in cirrhosis. In clinical practice, prerenal azotemia (PRA) is often distinguished from other types of AKI by volume expansion therapy. The aim of the current study was to investigate the accuracy of urinary biomarkers in the differential diagnosis between PRA and other types of AKI. Methods: A total of 65 patients with hepatitis B cirrhosis were prospectively included and divided into AKI and non-AKI groups. Patients with hepatitis B cirrhosis and AKI discontinue diuretics, vasodilators, and nephrotoxic drugs and give volume expansion therapy. The efficacy was judged after 48 h of treatment. Urinary biomarkers were measured at the time of diagnosis of AKI and 48 h after volume expansion therapy. Univariate and multivariate analyses were used to identify independent risk factors for nonresponse to volume expansion therapy. Results: Of the 65 patients, 49 patients with newly diagnosed AKI were screened in the study, and 16 hospitalized patients with hepatitis B cirrhosis without AKI at the same period were screened as the control group. In patients with cirrhosis and AKI, 29 (59.18%) patients were in the response group and 20 (40.81%) patients were in the nonresponse group. The mortality rate in the nonresponse group was significantly higher than that in the response group (75% vs. 13.8% p < 0.001). After logistic regression analysis, urinary neutrophil gelatinase-associated lipocalin (NGAL) and serum creatinine (SCr) at diagnosis of AKI showed significant association with nonresponse to volume expansion therapy. The cutoff values for SCr and urinary NGAL were 128.50 µmol/L and 90.75 ng/ml, respectively. The area under the receiver operating curve (AUC) for SCr and urinary NGAL was 0.815 and 0.831. Conclusion: Elevated urinary NGAL can reflect the degree of kidney injury and is an independent risk factor for nonresponse to volume expansion therapy in patients with hepatitis B cirrhosis and AKI.

Hepatorenal syndrome in acute-on-chronic liver failure with acute kidney injury: more questions requiring discussion

In cirrhosis with ascites, hepatorenal syndrome (HRS) is a specific prerenal dysfunction unresponsive to fluid volume expansion. Acute-on-chronic liver failure (ACLF) comprises a group of clinical syndromes with multiple organ failure and early high mortality. There are differences in the characterization of ACLF between the Eastern and Western medical communities. Patients with ACLF and acute kidney injury (AKI) have more structural injuries, contributing to confusion in diagnosing HRS-AKI. In this review, we discuss progress in the pathogenesis, diagnosis, and management of HRS-AKI, especially in patients with ACLF. Controversy regarding HRS-AKI in ACLF and acute liver failure, hepatic carcinoma, shock, sepsis, and chronic kidney disease is also discussed. Research on the treatment of HRS-AKI with ACLF needs to be more actively pursued to improve disease prognosis.

Baseline serum cystatin C as a marker of acute kidney injury in patients with acute-on-chronic liver failure

BACKGROUND

A creatinine-based estimation of the renal function lags behind the onset of disease process. Cystatin C is a new marker for acute kidney injury (AKI). However, data are limited in patients with acute-on-chronic liver failure (ACLF). We evaluated serum cystatin C as an early predictor of AKI in patients with ACLF.

METHODS

In a prospective observational study, patients with ACLF and normal serum creatinine level were included in the study. Serum cystatin C was analyzed with the development of AKI and the disease outcome.

RESULT

Forty-seven patients (mean age: 43.26±16.34 years; male:female: 2.35:1) were included in the study. AKI developed in 34% of patients during the hospital stay. Receiver operating characteristic (ROC) curve analysis revealed that the best cutoff for baseline cystatin C was 1.47 mg/L with a sensitivity of 0.94 and specificity of 0.68. The cystatin C ((area under the curve [AUC]=0.853) performance was better than that of the creatinine (AUC=0.699), Child-Turcotte-Pugh (CTP) (AUC=0.661), and model for end-stage liver disease-sodium (MELD-Na) (AUC=0.641). In the univariate analysis, age, platelet count, creatinine, estimated glomerular filtration rate (eGFR)-modification of diet in renal disease (MDRD), cystatin C, and estimated glomerular filtration rate-serum cystatin C (eGFRcysC) were significantly associated with AKI in ACLF patients. Cystatin C was an independent positive predictor of AKI. Cystatin C was positively correlated with the MELD-Na scores (r=0.374 and p=0.009).

CONCLUSION

Our study supports previous studies reporting that serum cystatin C is a better predictor for AKI development compared to serum creatinine. Cystatin C may be used as an early marker for new-onset AKI in hospitalized patients with ACLF.

Cystatin C: best biomarker for acute kidney injury and estimation of glomerular filtration rate in childhood cirrhosis

The objective of the study was to evaluate the diagnostic and prognostic role of serum cystatin C, urinary neutrophil gelatinase-associated lipocalin (NGAL), and renal resistive index (RRI) in AKI among pediatric cirrhotics. The study included cirrhotic children under 18 years of age. AKI was diagnosed as per Kidney Diseases-Improving Global Outcomes (KDIGO) guidelines. All patients underwent measurement of serum cystatin C, urinary NGAL, and RRI at baseline, 3 months, and 6 months. eGFR was calculated using both creatinine- and cystatin-based equations. Of the 247 cirrhotics admitted during the study, 100 gave consent and were included. Forty-one fulfilled the KDIGO definition of AKI of whom 22 showed resolution. Two of these children had a repeat AKI at 2 and 4 months after initial AKI; both resolved with medical management. On logistic regression analysis, serum cystatin C (OR: 544.8, 95% CI: 24.4-12170, p < 0.0005) and urinary NGAL (OR: 1.006, 95% CI: 1001-1.012, p = 0.019) were found to be significantly associated with AKI. Cystatin C alone was the best biomarker for diagnosing AKI in children with decompensation (OR: 486.7, p < 0.0005) or spontaneous bacterial peritonitis (p = 0.02). eGFR calculated by serum cystatin C-based formulas was more reliable than that calculated by creatinine-based equations.Conclusion: Serum cystatin C is the best biomarker for diagnosis of AKI in pediatric cirrhotics, especially with decompensation and SBP. eGFR calculated on serum cystatin C-based equations is more reliable than creatinine-based ones. What is Known: • Acute kidney injury (AKI) is a common complication in cirrhotic adults. • Newer biomarkers have diagnostic and prognostic role in adult cirrhotics. What is New: • Serum cystatin C is a useful biomarker to identify acute kidney injury in cirrhotic children with decompensation. • Glomerular filtration rate calculation is more accurate by cystatin-based equations than creatinine-based equations.

Therapeutic plasma exchange in liver failure

The multi-organ failure syndrome associated with acute and acute-on-chronic liver failure (ACLF) is thought to be mediated by overwhelming systemic inflammation triggered by both microbial and non-microbial factors. Therapeutic plasma exchange (TPE) has been proven to be an efficacious therapy in autoimmune conditions and altered immunity, with more recent data supporting its use in the management of liver failure. Few therapies have been shown to improve survival in critically ill patients with liver failure who are not expected to survive until liver transplantation (LT), who are ineligible for LT or who have no access to LT. TPE has been shown to reduce the levels of inflammatory cytokines, modulate adaptive immunity with the potential to lessen the susceptibility to infections, and reduce the levels of albumin-bound and water-bound toxins in liver failure. In patients with acute liver failure, high volume TPE has been shown to reduce the vasopressor requirement and improve survival, particularly in patients not eligible for LT. Standard volume TPE has also been shown to reduce mortality in certain sub-populations of patients with ACLF. TPE may be most favorably employed as a bridge to LT in patients with ACLF. In this review, we discuss the efficacy and technical considerations of TPE in both acute and acute-on-chronic liver failure.

Current knowledge about biomarkers of acute kidney injury in liver cirrhosis

Acute kidney injury (AKI) is common in advanced cirrhosis. Prerenal azotemia, hepatorenal syndrome, and acute tubular necrosis are the main causes of AKI in patients with cirrhosis. Evaluation of renal function and differentiation between functional and structural kidney injury are important issues in the management of cirrhosis. However, AKI in cirrhosis exists as a complex clinical spectrum rather than concrete clinical entity. Based on current evidence, changes in serum creatinine (Cr) levels remain the most appropriate standard for defining AKI in cirrhosis. However, serum Cr has a limited role in assessing renal function in this population. This review examines previous studies that investigated the ability of recent biomarkers for AKI in cirrhosis from the perspective of earlier and accurate diagnosis, classification of AKI phenotype, and prediction of clinical outcomes. Serum cystatin C and urine neutrophil gelatinase-associated lipocalin have been extensively studied in cirrhosis, and have facilitated improved diagnosis and prognosis prediction in patients with AKI. In addition, urine N-acetyl-β-D-glucosaminidase, interleukin 18, and kidney injury molecule 1 are other promising biomarkers for advanced cirrhosis. However, the clinical significance of these markers remains unclear because there are no cut-off values defining the normal range and differentiating phenotypes of AKI. In addition, AKI has been defined in terms of serum Cr, and renal biopsy-the gold standard-has not been carried out in most studies. Further discovery of innovate biomarkers and incorporation of various markers could improve the diagnosis and prognosis prediction of AKI, and will translate into meaningful improvements in patient outcomes.

Prevalence and short-term outcome of acute kidney injury in patients with acute-on-chronic liver failure: A meta-analysis

Acute kidney injury (AKI) in patients with acute-on-chronic liver failure (ACLF) is a distinct syndrome to that in patients with cirrhosis, yet is less characterized. The aim of this meta-analysis was to investigate the impact of AKI on outcome of ACLF. We searched PubMed, Web of Science and Cochrane Library for original articles that evaluated the impact of AKI on outcome of ACLF from 2011 to 2019. Odds ratio (OR) with 95% confidence interval (CI) for 1-month and 3-month mortality was calculated. The response rate of vasoconstrictor for hepatorenal syndrome (HRS)-AKI was assessed. Eight relevant articles with 3610 patients were included. The prevalence of AKI in ACLF patients was 41% (95% CI 32%-50%). The presence of AKI was significantly associated with 1-month mortality of ACLF (OR 3.98, 95% CI 3.09-5.12; P < .001) and 3-month mortality (OR 4.98, 95% CI 3.59-6.92; P < .001). Additionally, patients with AKI stage ≥2 showed a higher 3-month mortality than stage 1 (OR 3.89, 95% CI 2.60-5.82; P < .001), and those of stage 3 had a higher mortality than stage ≤2 (OR 3.77, 95% CI 2.10-6.77; P < .001). The pooled response rate of vasoconstrictors was 32% (95% CI 26%-37%). This meta-analysis indicated that about 40% of ACLF patients complicated with AKI and the presence of AKI substantially increased the short-term mortality, together with a poor response rate of vasoconstrictors for HRS-AKI.

Incidence, Mortality and Predictors of Acute Kidney Injury in Patients with Cirrhosis: A Systematic Review and Meta-analysis

Background and Aims: Acute kidney injury (AKI) is common in patients with cirrhosis but the incidence is heterogeneous among studies. We performed a meta-analysis to describe the incidence of AKI and its impact on patient mortality in patients with cirrhosis. We also evaluated the admission variables predicting development of AKI. Methods: A systematic search of various databases was performed up to November 2018. Meta-analyses were performed using random effects models. Results: Of 18,474 patients with cirrhosis from 30 selected studies, 5,648 developed AKI, with a pooled incidence of 29% (95% confidence interval [CI]: 28-30%, I 2 of 99%). In-hospital mortality assessed in eight studies was six-fold higher among AKI patients, as compared to those without AKI (odds ratio [OR] 6.72, 95% CI: 3.47-13, p<0.0001, I 2 of 70%). Three studies on patients admitted to intensive care showed about six-fold higher mortality among AKI patients (OR 5.90, 95% CI: 3.21-10.85, p>0.0001). Mortality remained significantly high, at days 30 and 90 and even at 1-year follow up after development of AKI. Of 12 admission variables analyzed, model for end-stage liver disease score, Child-Pugh-Turcotte stage C, presence of ascites, and presence of sepsis/septic shock were statistically significant risk factors for AKI. Conclusions: AKI occurred in about 29% of patients with cirrhosis and is associated with a six-fold increased risk of in-hospital mortality. Mortality remained high even in long-term follow-up of 1 year. Patients at risk for AKI development can be recognized at admission. Prospective studies are needed to develop strategies for improving outcome of these patients.

Effect of terlipressin on renal function in cirrhotic patients with acute upper gastrointestinal bleeding

BACKGROUND

Renal dysfunction is a serious morbidity in cirrhotic patients with acute upper gastrointestinal bleeding (AUGIB). Terlipressin is the first-line treatment choice for acute variceal bleeding and hepatorenal syndrome (HRS). This study aimed to assess the effect of terlipressin on renal function in patients with liver cirrhosis and AUGIB.

METHODS

We retrospectively reviewed 40 cirrhotic patients with AUGIB treated with terlipressin by an attending physician between January 2016 and June 2018. We analyzed the change of renal function parameters, including cystatin C (CysC) and creatinine (Cr), during the use of terlipressin and after terlipressin was stopped. We also identified the factors associated with renal function improvement in patients without active bleeding during the use of terlipressin.

RESULTS

During the use of terlipressin, CysC value was significantly reduced (1.3±0.8 vs. 1.1±0.7, P=0.001); Cr value was reduced, but the reduction was not statistically significant (68.8±24 vs. 65.5±23, P=0.817); the rate of CysC reduction was significantly higher in patients treated with terlipressin than those treated with somatostatin/octreotide (73.1% vs. 0%, P=0.005); the rate of Cr reduction was not significantly different between patients treated with terlipressin and somatostatin/octreotide (61.5% vs. 20%, P=0.148); no factor associated with CysC reduction was identified; higher hemoglobin, red blood cell, and platelet and lower prothrombin time and international normalized ratio at baseline were significantly associated with Cr reduction. After terlipressin was stopped, neither CysC nor Cr value was significantly reduced (P=0.852 and P=0.296).

CONCLUSIONS

Terlipressin may be beneficial on preventing renal function impairment in cirrhotic patients with AUGIB.

Terlipressin Is Superior to Noradrenaline in the Management of Acute Kidney Injury in Acute on Chronic Liver Failure

Hepatorenal syndrome (HRS) carries a high short-term mortality in patients with cirrhosis and acute on chronic liver failure (ACLF). Terlipressin and noradrenaline are routinely used in cirrhosis with HRS and have been found to be equally effective. There are no data comparing the efficacy of terlipressin with noradrenaline in ACLF patients with HRS. In an open-label, randomized controlled trial (RCT), consecutive patients with ACLF diagnosed with HRS acute kidney injury (AKI) were randomized to albumin with infusion of terlipressin (2-12 mg/day; n = 60) or noradrenaline (0.5-3.0 mg/h; n = 60). Response to treatment, course of AKI, and outcome were studied. Baseline characteristics, including AKI stage and sepsis-related HRS-AKI, were comparable between groups. Compared to noradrenaline, terlipressin achieved greater day 4 (26.1% vs. 11.7%; P = 0.03) and day 7 (41.7% vs. 20%; P = 0.01) response. Reversal of HRS was also better with terlipressin (40% vs. 16.7%; P = 0.004), with a significant reduction in the requirement of renal replacement therapy (RRT; 56.6% vs. 80%; P = 0.006) and improved 28-day survival (48.3% vs. 20%; P = 0.001). Adverse events limiting use of drugs were higher with terlipressin than noradrenaline (23.3% vs. 8.3%; P = 0.02), but were reversible. On multivariate analysis, high Model for End-Stage Liver Disease (MELD; odds ratio [OR], 1.10; confidence interval [CI] = 1.009-1.20; P = 0.03) and noradrenaline compared to terlipressin (OR, 3.05; CI = 1.27-7.33; P = 0.01) predicted nonresponse to therapy. Use of noradrenaline compared to terlipressin was also predictive of higher mortality (hazard ratio [HR], 2.08; CI = 1.32-3.30; P = 0.002). Conclusion: AKI in ACLF carries a high mortality. Infusion of terlipressin gives earlier and higher response than noradrenaline, with improved survival in ACLF patients with HRS-AKI.

Intermittent high-flux albumin dialysis with continuous venovenous hemodialysis for acute-on-chronic liver failure and acute kidney injury

Acute-on-chronic liver failure (ACLF) requiring intensive medical care and associated with acute kidney injury (AKI) has a mortality rate as high as 90% due to the lack of effective therapies. In this study, we assessed the effects of intermittent high-flux single-pass albumin dialysis (SPAD) coupled with continuous venovenous hemodialysis (CVVHD) on 28-day and 90-day survival and an array of clinical and laboratory parameters in patients with severe ACLF and renal insufficiency. Sixteen patients were studied. The diagnosis of ACLF and AKI was made in accordance with current EASL Clinical Practice Guidelines, including the recommendations of the International Club of Ascites. All patients received SPAD/CVVHD treatments as the blood purification therapy to support liver, kidneys, and other organs. Five patients were transplanted and 11 were not listed for transplantation because of active alcoholism. Data at the initiation of SPAD/CVVHD were compared with early morning data after the termination of the extracorporeal treatment phase. All patients had ACLF and renal insufficiency with 13/16 additionally fulfilling the AKI criteria. A total of 37 SPAD/CVVHD treatments were performed [2.3 ± 1.4]. The baseline MELD-Na score was 37.6 ± 6.6 and decreased to 33.4 ± 8.7 after SPAD/CVVHD (P < 0.001). In parallel, the CLIF-C ACLF grade and OF score, estimated at 28- and 90-day mortality, AKI stage, hepatic encephalopathy grade, and liver function tests were lowered (P = 0.001-0.032). The 28- and 90-day survivals were 56.2% overall and 53.8% in AKI. Survival in patients not transplanted (n = 11) was 45.4%. In patients with severe ACLF and AKI, the renal replacement therapy coupled with high-performance albumin dialysis improved estimated 28- and 90-day survival and several key clinical and laboratory parameters. It is postulated that these results may be further improved with earlier intervention and more SPAD treatments per patient. High-performance albumin dialysis improves survival and key clinical and laboratory parameters in severe ACLF and AKI.

Profile, risk factors and outcome of acute kidney injury in paediatric acute-on-chronic liver failure

BACKGROUND & AIMS

There are no studies on acute kidney injury in paediatric acute-on-chronic liver failure. This study was planned with aim to describe the clinical presentation and outcome of acute kidney injury among paediatric acute-on-chronic liver failure patients.

METHODS

Data of all children 1-18 years of age presenting with acute chronic liver failure (Asia pacific association for the study of the liver definition) was reviewed. Acute kidney injury was defined as per Kidney Diseases-Improving Global Outcomes guidelines. Poor outcome was defined as death or need for liver transplant within 3 months of development of acute kidney injury.

RESULTS

A total of 84 children with acute-on-chronic liver failure were presented to us in the study period. Acute kidney injury developed in 22.6% of patients with acute-on-chronic liver failure. The median duration from acute-on-chronic liver failure to development of acute kidney injury was 4 weeks (Range: 2-10 weeks). The causes of acute kidney injury were hepatorenal syndrome (31.6%), sepsis (31.6%), nephrotoxic drugs (21%), dehydration (10.5%) and bile pigment related acute tubular necrosis in one patient. On univariate analysis, higher baseline bilirubin, higher international normalized ratio, higher paediatric end stage liver disease, presence of systemic inflammatory response syndrome and presence of spontaneous bacterial peritonitis had significant association with presence of acute kidney injury. On logistic regression analysis, presence of systemic inflammatory response syndrome (adjusted OR: 8.659, 95% CI: 2.18-34.37, P = .002) and higher baseline bilirubin (adjusted OR: 1.07, 95% CI: 1.008-1.135, P = .025) were independently associated with presence of acute kidney injury. Of the patients with acute kidney injury, 5(26.3%) survived with native liver, 10(52.6%) died and 4 (21.1%) underwent liver transplantation.

CONCLUSION

Acute kidney injury developed in 22.6% of children with acute-on-chronic liver failure. Bilirubin more than 17.7 mg/dL and presence of systemic inflammatory response syndrome were high risk factors for acute kidney injury. Development of acute kidney injury in a child with acute-on-chronic liver failure suggests poor outcome and need for early intervention.

Management of acute-on-chronic liver failure: an algorithmic approach

Acute-on-chronic liver failure (ACLF) is a distinct syndrome of liver failure in a patient with chronic liver disease presenting with jaundice, coagulopathy and ascites and/or hepatic encephalopathy, developing following an acute hepatic insult and associated with high 28-day mortality. The definition though lacks global consensus, excludes patients with known distinct entities such as acute liver failure and those with end-stage liver disease. The initial Systemic Inflammatory Response Syndrome (SIRS) because of cytokine storm in relation to acute insult and/or subsequent development of sepsis due to immunoparalysis leads to extrahepatic organ failure. These cascades of events progress through a 'Golden Window' period of about 7 days, subsequent to which majority of the patients develop complications, such as sepsis and extrahepatic organ failure. Prevention of sepsis, support of organs and management of organ failure (commonly hepatic, renal, cerebral, coagulation) and early referral for transplant is crucial. The APASL ACLF research consortium (AARC) liver failure score is a dynamic prognostic model for management decisions and is superior to existing models. Aggressive multidisciplinary approach can lead to a transplant-free survival in nearly half of the cases. The present review provides an algorithmic approach to management of organ failure, sepsis prevention, use of dynamic prognostic models for management decision and is aimed to improve the skills for managing and improving the outcomes of such critically ill patients.

Acute kidney injury in acute-on-chronic liver failure is different from in decompensated cirrhosis

AIM

To evaluate the differences in acute kidney injury (AKI) between acute-on-chronic liver failure (ACLF) and decompensated cirrhosis (DC) patients.

METHODS

During the period from December 2015 to July 2017, 280 patients with hepatitis B virus (HBV)-related ACLF (HBV-ACLF) and 132 patients with HBV-related DC (HBV-DC) who were admitted to our center were recruited consecutively into an observational study. Urine specimens were collected from all subjects and the levels of five urinary tubular injury biomarkers were detected,including neutrophil gelatinase-associated lipocalin (NGAL), interleukin-18 (IL-18), liver-type fatty acid binding protein (L-FABP), cystatin C (CysC), and kidney injury molecule-1 (KIM-1). Simultaneously, the patient demographics, occurrence and progression of AKI, and response to terlipressin therapy were recorded. All patients were followed up for 3 mo or until death after enrollment.

RESULTS

AKI occurred in 71 and 28 of HBV-ACLF and HBV-DC patients, respectively (25.4% vs 21.2%, P = 0.358). Among all patients, the levels of four urinary biomarkers (NGAL, CysC, L-FABP, IL-18) were significantly elevated in patients with HBV-ACLF and AKI (ACLF-AKI), compared with that in patients with HBV-DC and AKI (DC-AKI) or those without AKI. There was a higher proportion of patients with AKI progression in ACLF-AKI patients than in DC-AKI patients (49.3% vs 17.9%, P = 0.013). Forty-three patients with ACLF-AKI and 19 patients with DC-AKI were treated with terlipressin. The response rate of ACLF-AKI patients was significantly lower than that of patients with DC-AKI (32.6% vs 57.9%, P = 0.018). Furthermore, patients with ACLF-AKI had the lowest 90 d survival rates among all groups (P < 0.001).

CONCLUSION

AKI in ACLF patients is more likely associated with structural kidney injury, and is more progressive, with a poorer response to terlipressin treatment and a worse prognosis than that in DC patients.

Value of cystatin C, β2 macroglobulin, serum creatinine, and blood urea nitrogen in predicting hepatorenal syndrome in patients with acute-on-chronic liver failure

AIM

To assess the predictive value of cystatin C (Cys-C), β2 macroglobulin (β2-MG), serum creatinine (Scr), and blood urea nitrogen (BUN) for hepatorenal syndrome (HRS) in patients with acute-on-chronic liver failure (ACLF) .

METHODS

Thirty-six ACLF patients with HRS (HRS group) treated at our hospital from February 2014 to December 2017 were analyzed retrospectively. Thirty-six patients with ACLF without HRS were selected as an ACLF group, and 50 patients with chronic liver disease (CLD) were selected as a CLD group. Cys-C, β2-MG, Scr, and BUN were compared between the three groups. The receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic efficacy of Cys-C, β2-MG, Scr, and BUN, alone or in combination, in predicting HRS in patients with ACLF.

RESULTS

The levels of Cys-C, β2-MG, Scr, and BUN in the three groups were statistically different (F = 47.330, 23.693, 41.220, 26.715; P = 0.000 for all). Compared with the CLD and ACLF groups, Cys-C (t = 9.386, 4.807, P = 0.000 for both), β2-MG (t = 30.265, 4.116; P = 0.000 for both), Scr (t = 7.457, 7.415; P = 0.000 for both), and BUN (t = 6.608, 5.014; P = 0.000 for both) were significantly increased in the HRS group. ROC curve analysis showed that Scr had the highest AUC (0.799), followed by Cys-C (AUC = 0.789), β2-MG (AUC = 0.741), and BUN (AUC = 0.910). The combination of Cys-C, β2-MG, and Scr (AUC = 0.910) performed significantly better than any of the four indexes alone. Using the best cutoff point of the ROC curve as the predictive index, the diagnostic accuracy rate of the combination of Cys-C, β2-MG, and Scr for HRS was 80.33% (sensitivity, 91.67%; specificity, 75.58%; positive predictive value, 61.11%; negative predictive value, 95.59%). The sensitivity of combined indexes was significantly higher than any of the four indexes alone (χ² = 10, 8.692, 7.432, 3.956; P = 0.002, 0.003, 0.006, 0.047).

CONCLUSION

The levels of Cys-C, β2-MG, Scr, and BUN in ACLF patients with HRS significantly increase. The combination of Cys-C, β2-MG, and Scr has higher accuracy for predicting HRS in ACLF patients.

Development of predisposition, injury, response, organ failure model for predicting acute kidney injury in acute on chronic liver failure

BACKGROUND AND AIM

There is limited data on predictors of acute kidney injury in acute on chronic liver failure. We developed a PIRO model (Predisposition, Injury, Response, Organ failure) for predicting acute kidney injury in a multicentric cohort of acute on chronic liver failure patients.

PATIENTS AND METHODS

Data of 2360 patients from APASL-ACLF Research Consortium (AARC) was analysed. Multivariate logistic regression model (PIRO score) was developed from a derivation cohort (n=1363) which was validated in another prospective multicentric cohort of acute on chronic liver failure patients (n=997).

RESULTS

Factors significant for P component were serum creatinine[(≥2 mg/dL)OR 4.52, 95% CI (3.67-5.30)], bilirubin [(<12 mg/dL,OR 1) vs (12-30 mg/dL,OR 1.45, 95% 1.1-2.63) vs (≥30 mg/dL,OR 2.6, 95% CI 1.3-5.2)], serum potassium [(<3 mmol/LOR-1) vs (3-4.9 mmol/L,OR 2.7, 95% CI 1.05-1.97) vs (≥5 mmol/L,OR 4.34, 95% CI 1.67-11.3)] and blood urea (OR 3.73, 95% CI 2.5-5.5); for I component nephrotoxic medications (OR-9.86, 95% CI 3.2-30.8); for R component,Systemic Inflammatory Response Syndrome,(OR-2.14, 95% CI 1.4-3.3); for O component, Circulatory failure (OR-3.5, 95% CI 2.2-5.5). The PIRO score predicted acute kidney injury with C-index of 0.95 and 0.96 in the derivation and validation cohort. The increasing PIRO score was also associated with mortality (P<.001) in both the derivation and validation cohorts.

CONCLUSIONS

The PIRO model identifies and stratifies acute on chronic liver failure patients at risk of developing acute kidney injury. It reliably predicts mortality in these patients, underscoring the prognostic significance of acute kidney injury in patients with acute on chronic liver failure.

Acute-on-chronic Liver Failure

Acute-on-chronic liver failure (ACLF) is a distinct entity that differs from acute liver failure and decompensated cirrhosis in timing, presence of treatable acute precipitant, and course of disease, with a potential for self-recovery. The core concept is acute deterioration of existing liver function in a patient of chronic liver disease with or without cirrhosis in response to an acute insult. The insult should be a hepatic one and presentation in the form of liver failure (jaundice, encephalopathy, coagulopathy, ascites) with or without extrahepatic organ failure in a defined time frame. ACLF is characterized by a state of deregulated inflammation. Initial cytokine burst presenting as SIRS, progression to CARS and associated immunoparalysis leads to sepsis and multi-organ failure. Early identification of the acute insult and mitigation of the same, use of nucleoside analogue in HBV-ACLF, steroid in severe alcoholic hepatitis, steroid in severe autoimmune hepatitis and/or bridging therapy lead to recovery, with a 90-day transplant-free survival rate of up to 50 %. First-week presentation is crucial concerning SIRS/sepsis, development, multiorgan failure and consideration of transplant. A protocol-based multi-disciplinary approach including critical care hepatology, early liver transplant before multi-organ involvement, or priority for organ allocation may improve the outcome. Presentation with extrahepatic organ involvement or inclusion of sepsis as an acute insult in definition restricts the therapy, i.e., liver transplant or bridging therapy, and needs serious consideration. Augmentation of regeneration, cell-based therapy, immunotherapy, and gut microbiota modulation are the emerging areas and need further research.

Acute-on-chronic liver failure: terminology, mechanisms and management

Acute-on-chronic liver failure (ACLF) is a distinct clinical entity and differs from acute liver failure and decompensated cirrhosis in timing, presence of acute precipitant, course of disease and potential for unaided recovery. The definition involves outlining the acute and chronic insults to include a homogenous patient group with liver failure and an expected outcome in a specific timeframe. The pathophysiology of ACLF relates to persistent inflammation, immune dysregulation with initial wide-spread immune activation, a state of systematic inflammatory response syndrome and subsequent sepsis due to immune paresis. The disease severity and outcome can be predicted by both hepatic and extrahepatic organ failure(s). Clinical recovery is expected with the use of nucleoside analogues for hepatitis B, and steroids for severe alcoholic hepatitis and, possibly, severe autoimmune hepatitis. Artificial liver support systems help remove toxins and metabolites and serve as a bridge therapy before liver transplantation. Hepatic regeneration during ongoing liver failure, although challenging, is possible through the use of growth factors. Liver transplantation remains the definitive treatment with a good outcome. Pre-emptive antiviral agents for hepatitis B before chemotherapy to prevent viral reactivation and caution in using potentially hepatotoxic drugs can prevent the development of ACLF.