The use of urinary kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin for diagnosis of hepato-renal syndrome in advanced cirrhotic patients.

BACKGROUND: Chronic liver disease is a common and important clinical problem.Hepatorenal syndrome (HRS) is a life threatening complication. Serum creatinine (Cr) remains the only conventional indicator of renal function. However, the interpretation of serum Cr level can be confounded by malnutrition and reduced muscle mass often observed in patients with severe liver disease. Here, we present a cross-sectional study to explore the sensitivity and specificity of other markers as urinary KIM-1 and NGAL for cases of HRS. METHODS: Cross-sectional study was conducted on 88 patients who were admitted to Alexandria main university hospital. Enrolled patients were divided in two groups; group 1: patients with advanced liver cirrhosis (child B and C) who have normal kidney functions while group 2: patients who developed HRS. Stata© version 14.2 software package was used for analysis. RESULTS: Group 1 included 18 males and 26 females compared to 25 males and 19 females in group 2 (p = 0.135). Only the urinary KIM-1 showed a statistically significant difference between both groups in the multivariate logistic regression analysis adjusted for gender, serum bilirubin, serum albumin, INR, serum K, AST and ALT levels. CONCLUSION: In conclusion, our study aligns with prior research, as seen in the consistent findings regarding Urinary NGAL elevation in cirrhotic patients with AKI. Urinary KIM-1, independent of Urinary NGAL, may have a role in precisely distinguishing between advanced liver cirrhosis and HRS and merits further exploration.

Hepatorenal Syndrome Type 1: Diagnosis and Treatment.

Hepatorenal syndrome (HRS) is a feared complication in patients with advanced cirrhosis and is associated with significant morbidity and mortality. While recognized as a distinct physiologic condition for well over one hundred years, a lack of objective diagnostic tests has made the diagnosis one of exclusion. Since 1979, multiple sets of diagnostic criteria have been proposed. Though varying in detail, the principal intent of these criteria is to identify patients with severe, functional acute kidney injury that is unresponsive to volume resuscitation and exclude those with structural injury. However, accurate differential diagnosis remains challenging. Recently, multiple urinary biomarkers of kidney injury, including neutrophil gelatinase-associated lipocalin, have been studied as a means of objectively phenotyping etiologies of acute kidney injury in patients with cirrhosis. Along with markers reflecting tubular functional integrity, including the fractional excretion of sodium, injury markers will likely be incorporated into future diagnostic criteria. Making an accurate diagnosis is critical, as therapeutic options exist for HRS but must be given in a timely manner and only to those patients likely to benefit. Terlipressin, an analog of vasopressin, is the first line of therapy for HRS in much of the world and has recently been approved for use in the United States. Significant questions remain regarding the optimal dosing strategy, metrics for titration, and the potential role of point-of-care ultrasound to help guide concurrent albumin administration.

Renal damage in Hepatorenal Syndrome: A still unsolved issue.

Acute kidney injury (AKI) is a common complication of cirrhosis, burdened by high morbidity and mortality rates and progression to chronic kidney disease. Hepatorenal syndrome (HRS) is a peculiar type of functional AKI observed in cirrhotic patients with ascites. HRS diagnosis is still clinical, once pre-renal azotemia and intrinsic kidney damage have been excluded by applying well-established and internationally adopted criteria. HRS is considered reversible because of the absence of intrinsic renal damage. However, HRS reversibility has been questioned, due to the lack of response to treatment with vasoconstrictors plus albumin in a relevant percentage of patients and to the persistence of renal dysfunction in HRS patients who underwent liver transplantation (LT). Indeed, LT is the only ultimate treatment, as it solves both liver failure and portal hypertension. Thus, the presence of renal damage in HRS can be hypothesized. In this scenario, neutrophil gelatinase-associated lipocalin (NGAL), one of the most promising biomarkers, may help in characterizing the type of renal injury, distinguishing between HRS and acute tubular necrosis. This review gathers the available evidence in favor and against the presence of structural lesions in HRS in terms of either renal histology and urinary biomarkers with a particular focus on NGAL. The ability to properly characterize which component of renal dysfunction prevails - functional rather than structural - entails a relevant clinical impact for the treatment of these patients, both in terms of medical therapy and liver vs. combined liver-kidney transplantation.

Outcomes of patients with hepatorenal syndrome undergoing liver transplantation in the era of terlipressin.

BACKGROUND: The efficacy of terlipressin in improving pre-liver transplant renal function in hepatorenal syndrome (HRS) has been well documented, however, its impact on post-transplant renal function remains poorly described. This study aims to describe the impact of HRS and terlipressin on post-liver transplant renal function and survival. METHODS: A single-centre, retrospective, observational study was conducted to identify post-transplant outcomes of patients diagnosed with HRS undergoing liver transplant (HRS cohort) and those undergoing transplant for non-HRS, non-hepatocellular carcinoma cirrhotic indications (comparator cohort) between January 1997 and March 2020. The primary outcome was serum creatinine at 180 days post-liver transplant. Other renal outcomes and overall survival were secondary outcomes. RESULTS: 109 patients with HRS and 502 comparator patients underwent liver transplant. The comparator cohort was younger than the HRS cohort (53 vs. 57 years, P < 0.001). The median creatinine at day 180 post-transplant was higher in the HRS transplant group (119 µmol/L vs. 103 µmol/L, P < 0.001), however, this association lost significance following multivariate analysis. Seven patients (7%) in the HRS cohort received a combined liver-kidney transplant. There was no significant difference in the 12-month post-transplant survival between the two groups (94% vs. 94%, P = 0.5). CONCLUSION: Patients with HRS treated with terlipressin who subsequently undergo liver transplantation have post-transplant renal and survival outcomes comparable to patients transplanted for cirrhosis without HRS. This study supports the practice of liver-only transplant in this cohort and the reservation of renal allografts for those who have primary renal disease.

Severe TAFRO Syndrome Mimicking Hepatorenal Syndrome Successfully Treated with a Multidisciplinary Approach: A Case Report and Literature Review.

Finding the ideal balance between efficacy and safety of immunosuppression is challenging, particularly in cases of severe TAFRO syndrome. We herein report a 60-year-old man diagnosed with grade 5 TAFRO syndrome mimicking hepatorenal syndrome that was successfully treated by glucocorticoid, tocilizumab, and cyclosporin despite virus infection. Furthermore, by examining 14 peer-reviewed remission cases, we revealed that the recovery periods among inflammation, renal dysfunction, and thrombocytopenia were quite different, with recovery from thrombocytopenia notably slow. All patients requiring dialysis were successfully withdrawn from dialysis, and the reversibility from kidney injury was good. This clinical information will help clinicians plan treatments and tailor the intensity of immunosuppression.

Cholemic Nephrosis: An Autopsy Study of a Forgotten Entity.

OBJECTIVE: The aim of the study is to do a clinicopathologic study of post mortem kidney biopsies with significant deposition of bilirubin pigment within tubular epithelial cells and in the lumen of distal tubules as a bile cast. MATERIAL AND METHOD: All post mortem specimens with acute tubular necrosis, with the presence of bile casts in tubules or bile pigment deposition in the tubular epithelium during the period 2015-2018 were examined for gross and histopathology along with biochemical parameters and viral markers. RESULTS: Bile casts with sloughed renal tubular epithelial cells and occasional macrophages were present in the distal convoluted tubule in 78.6% of biopsies (11/14). The plugging of distal convoluted tubule with casts was similar to that seen in myeloma and myoglobin cast nephropathies. Bilirubin pigment deposition was present in 35.7% (5/14) of cases. The frequency of bile casts in each biopsy was variable and it did not have any association with serum bilirubin levels or etiology of liver dysfunction. A striking difference from earlier studies is the high number of toxin-induced liver damage including six cases of paraquat and 2 cases of yellow phosphorus poisoning. CONCLUSION: This study proves importance of the bile cast nephropathy as a reason for kidney injury, especially with varied hepatotoxic etiologies, especially paraquat and yellow phosphorus.

Urinary NGAL as a Diagnostic and Prognostic Marker for Acute Kidney Injury in Cirrhosis: A Prospective Study.

INTRODUCTION: Urinary neutrophil gelatinase-associated lipocalin (NGAL) has shown promise in differentiating acute tubular necrosis (ATN) from other types of acute kidney injuries (AKIs) in cirrhosis, particularly hepatorenal syndrome (HRS). However, NGAL is not currently available in clinical practice in North America. METHODS: Urinary NGAL was measured in a prospective cohort of 213 US hospitalized patients with decompensated cirrhosis (161 with AKI and 52 reference patients without AKI). NGAL was assessed for its ability to discriminate ATN from non-ATN AKI and to predict 90-day outcomes. RESULTS: Among patients with AKI, 57 (35%) had prerenal AKI, 55 (34%) had HRS, and 49 (30%) had ATN, with a median serum creatinine of 2.0 (interquartile range 1.5, 3.0) mg/dL at enrollment. At an optimal cutpoint of 244 µg/g creatinine, NGAL distinguished ATN (344 [132, 1,429] µg/g creatinine) from prerenal AKI (45 [0, 154] µg/g) or HRS (110 [50, 393] µg/g; P < 0.001), with a C statistic of 0.762 (95% confidence interval 0.682, 0.842). By 90 days, 71 of 213 patients (33%) died. Higher median NGAL was associated with death (159 [50, 865] vs 58 [0, 191] µg/g; P < 0.001). In adjusted and unadjusted analysis, NGAL significantly predicted 90-day transplant-free survival (P < 0.05 for all Cox models) and outperformed Model for End-Stage Liver Disease score by C statistic (0.697 vs 0.686; P = 0.04), net reclassification index (37%; P = 0.008), and integrated discrimination increment (2.7%; P = 0.02). DISCUSSION: NGAL differentiates the type of AKI in cirrhosis and may improve prediction of mortality; therefore, it holds potential to affect management of AKI in cirrhosis.

Hepatorenal syndrome: a historical appraisal of its origins and conceptual evolution.

The hepatorenal syndrome (HRS), a progressive but potentially reversible deterioration of kidney function, constitutes a serious complication of hepatic decompensation. Coexistence of liver/kidney damage, mentioned in the dropsy literature, was highlighted by Richard Bright in 1827 and confirmed in 1840 by his contemporary nephrology pioneer Pierre Rayer. Cholemic nephrosis was described in 1861 by Friedrich Frerichs, and the renal tubular lesions of HRS by Austin Flint in 1863. The term "acute hepato-nephritis" was introduced in 1916 by Paul Merklen, and its chronic form was designated HRS by Marcel Dérot in 1930s. HRS then was applied to renal failure in biliary tract surgery and to cases of coexistent renal and hepatic failure of diverse etiology. The pathogenesis of HRS was elucidated during the 1950 studies of renal physiology. Notably, studies of salt retention in edema and its relation to regulating the circulating plasma volume by John Peters and subsequently Otto Gauer defined the concept of "effective blood volume" and the consequent elucidation of ascites formation in liver failure. Parallel studies of intrarenal hemodynamics demonstrated severe renal vasoconstriction and preferential cortical ischemia to account for the functional renal dysfunction of HRS. Dialysis and liver or combined liver-kidney transplantation transformed the fatal HRS of old into a treatable disorder by the 1970s. Elucidation of the pathogenetic mechanisms of renal injury and refinements in definition, classification, and diagnosis of HRS since then have allowed for earlier therapeutic intervention with combined i.v. albumin and vasoconstrictor therapy, enabling the continued improvement of patient outcomes.

Effectiveness of terlipressin for prevention of complications after major liver resection - A randomized placebo-controlled trial.

BACKGROUND: Elevated portal pressure in response to major liver resection is associated with impaired liver regeneration and increased postoperative complications. Terlipressin, a splanchnic vasoconstrictor used for treatment of hepatorenal syndrome, was tested for reduction of complications and renal protection after liver resection. METHODS: A randomized double-blinded placebo-controlled trial including patients undergoing elective major liver resection was performed. Terlipressin was administered to patients in the intervention group for five days. The primary outcome parameter was the incidence of a clinical composite endpoint of following liver specific complications 6 weeks after surgery: liver failure, ascites, bile leakage, intra-abdominal abscess and operative mortality. Postoperative kidney function was assessed as a secondary endpoint. RESULTS: 150 patients (mean age 63.4 years, 73.3% male) were included. No difference was found in the composite endpoint between the placebo and intervention group (32.8% versus 30.8%, relative risk 1.066, 95%CI 0.643 to 1.769, p = 0.85). Patients receiving terlipressin showed a significant lower decrease in postoperative estimated glomerular filtration rate compared to placebo (two way ANOVA, p = 0.005). CONCLUSION: Perioperative administration of terlipressin during major liver surgery did not affect a composite endpoint of liver specific complications, but significantly protected from postoperative deterioration of kidney function compared to placebo. CLINICALTRIALS. GOV IDENTIFIER: NCT01921985.

Surgery in Patients with Portal Hypertension.

Patients with portal hypertension will increasingly present for nontransplant surgery because of the increasing incidence of, and improving long-term survival for, chronic liver disease. Such patients have increased perioperative morbidity and mortality caused by the systemic pathophysiology of liver disease. Preoperative assessment should identify modifiable causes of liver injury and distinguish between compensated and decompensated cirrhosis. Risk stratification, which is crucial to preparing patients and their families for surgery, relies on scores such as Child-Turcotte-Pugh and Model for End-stage Liver Disease to translate disease severity into quantified outcomes predictions. Risk factors for postoperative complications should also be recognized.

Free Cortisol Is a More Accurate Marker for Adrenal Function and Does Not Correlate with Renal Function in Cirrhosis.

BACKGROUND: The accuracy of diagnosis and clinical implications of the hepatoadrenal syndrome, as currently diagnosed using total cortisol, remain to be validated. AIM: The aim of this study was to assess adrenal function using free cortisol in stable cirrhosis and study the potential implications of any abnormalities for renal and/or cardiac function. METHODS: Sixty-one stable consecutively enrolled patients with cirrhosis underwent assessment of adrenal function using the low-dose short Synacthen test, renal function by 51Cr-EDTA glomerular filtration rate (GFR), and cardiac function by two-dimensional echocardiography. RESULTS: Eleven patients (18%) had total peak cortisol (PC) < 500 nmol/L, but no patient had free PC < 33 nmol/L indicating that diagnosis of AI using total cortisol is not confirmed using free cortisol. Free cortisol did not correlate with GFR or parameters of cardiac function. Patients with higher Child-Pugh class had progressively lower free cortisol. Patients with low GFR < 60 mL/min (N = 22) had more frequently grade II-III diastolic dysfunction (66.7% vs. 17.6%; p = 0.005) and had higher Child-Pugh and MELD score compared to those with normal GFR. CONCLUSIONS: Diagnosis of AI using total cortisol is not confirmed using free cortisol and is thus considered unreliable in cirrhosis. Free cortisol is not associated with renal or cardiac dysfunction. Lower free cortisol in more advanced stages of liver disease might be secondary to decreased synthesis due to lower cholesterol levels. Irrespective of free cortisol, parameters of cardiac dysfunction are associated with renal impairment supporting the cardio-renal hypothesis.

Clinical utility of urinary neutrophil gelatinase-associated lipocalin and serum cystatin C in a cohort of liver cirrhosis patients with renal dysfunction: a challenge in the diagnosis of hepatorenal syndrome.

OBJECTIVES: This study aimed to assess urinary neutrophil gelatinase-associated lipocalin (uNGAL) and serum cystatin C (sCys C) in liver cirrhosis patients with renal dysfunction and to evaluate their role in the diagnosis of the hepatorenal syndrome (HRS). PATIENTS AND METHODS: Forty-five liver cirrhosis patients were enrolled in the study and they were divided into three groups; the first group included 15 patients with normal renal function, the second group included 15 patients with HRS; and the third group included 15 patients with chronic kidney disease (CKD). There was a fourth group, which included 15 healthy controls. Liver and renal function tests, as well as the estimated glomerular filtration rate were determined. uNGAL was measured using the enzyme-linked immunosorbent assay, and the uNGAL/urinary creatinine concentration (UCC) ratio was calculated. sCys C was measured using the particle-enhanced immunoturbidimetric assay. RESULTS: The ratios of uNGAL and uNGAL/UCC were the highest among HRS patients. The combined uNGAL/UCC ratio and sCys C improved the sensitivity of diagnosis to 93.33% and specificity to 76.67%, with the highest area under the curve of 0.944, 95% confidence interval of 0.879-1.0 (P<0.001). The three biomarkers could successfully identify HRS at the following cutoffs: 84.94 ng/ml, 0.6 ng/mg, and 1.6 mg/l, respectively. Significant positive correlations were found between uNGAL, uNGAL/UCC ratios as well as sCys C and KDIGO stage in liver cirrhosis patients with CKD. CONCLUSION: uNGAL and a better uNGAL/UCC ratio can be used alone or together with serum cystatin C as early biomarkers for HRS among patients with decompensated liver cirrhosis. Moreover, uNGAL, uNGAL/UCC as well as serum cystatin C could aid the prognostic assessment of cirrhotic patients with CKD.

Joubert Syndrome: Ophthalmological Findings in Correlation with Genotype and Hepatorenal Disease in 99 Patients Prospectively Evaluated at a Single Center.

PURPOSE: Joubert syndrome (JS) is caused by mutations in >34 genes that encode proteins involved with primary (nonmotile) cilia and the cilium basal body. This study describes the varying ocular phenotypes in JS patients, with correlation to systemic findings and genotype. DESIGN: Patients were systematically and prospectively examined at the National Institutes of Health (NIH) Clinical Center in the setting of a dedicated natural history clinical trial. PARTICIPANTS: Ninety-nine patients with JS examined at a single center. METHODS: All patients underwent genotyping for JS, followed by complete age-appropriate ophthalmic examinations at the NIH Clinical Center, including visual acuity (VA), fixation behavior, lid position, motility assessment, slit-lamp biomicroscopy, dilated fundus examination with an indirect ophthalmoscope, and retinoscopy. Color and fundus autofluorescence imaging, Optos wide-field photography (Dunfermline, Scotland, UK), and electroretinography (ERG) were performed when possible. MAIN OUTCOME MEASURES: The VA (with longitudinal follow-up where possible), ptosis, extraocular muscle function, retinal and optic nerve status, and retinal function as measured by ERG. RESULTS: Among patients with JS with quantifiable VA (68/99), values ranged from 0 logarithm of the minimum angle of resolution (logMAR) (Snellen 20/20) to 1.5 logMAR (Snellen 20/632). Strabismus (71/98), nystagmus (66/99), oculomotor apraxia (60/77), ptosis (30/98), coloboma (28/99), retinal degeneration (20/83), and optic nerve atrophy (8/86) were identified. CONCLUSIONS: We recommend regular monitoring for ophthalmological manifestations of JS beginning soon after birth or diagnosis. We demonstrate delayed visual development and note that the amblyogenic time frame may last significantly longer in JS than is typical. In general, patients with coloboma were less likely to display retinal degeneration, and those with retinal degeneration did not have coloboma. Severe retinal degeneration that is early and aggressive is seen in disease caused by specific genes, such as CEP290- and AHI1-associated JS. Retinal degeneration in INPP5E-, MKS1-, and NPHP1-associated JS was generally milder. Finally, ptosis surgery can be helpful in a subset of patients with JS; decisions as to timing and benefit/risk ratio need to be made on an individual basis according to expert consultation.

Renal Function in Cirrhosis: A Critical Review of Available Tools.

Patients with cirrhosis have a high prevalence of renal dysfunction. The susceptibility to renal dysfunction is due to both the severe splanchnic arterial vasodilation and the systemic inflammation observed in these patients. An accurate assessment of renal function is recommended in all patients with cirrhosis. Indeed, the renal function assessment guides the management of patients, helps to refine prognosis and to define transplant strategies. Despite its limitations, serum creatinine is still the most used biomarker for the estimation of glomerular filtration rate (GFR) and the assessment of acute kidney injury (AKI) in patients with cirrhosis. New biomarkers of GFR such as cystatin C may improve the assessment of GFR and the prognostic stratification in these patients. AKI is a life-threatening complication and needs a timely management. The differential diagnosis between hepatorenal syndrome (HRS) and acute tubular necrosis (ATN) is tricky in clinical practice. New biomarkers of kidney injury, such as neutrophil gelatinase-associated lipocalin and interleukin-18, represent useful tools in refining the discrimination between HRS and ATN. Patients with HRS need a prompt treatment with vasoconstrictors and albumin and a rapid evaluation for liver transplant eligibility. In this article, the authors reviewed the available tools in the diagnosis and management of renal dysfunction in cirrhosis.

Hepatorenal syndrome in the era of acute kidney injury.

Acute kidney injury (AKI) is a frequent complication of patients with advanced cirrhosis that it is associated with increased hospital admissions and decreased survival. The definition of AKI in cirrhosis has been recently modified and the new diagnostic criteria are based on small changes in serum creatinine with respect to previous values, occurring within a short period of time. The use of this new definition may lead to an earlier identification of renal impairment and better prognostic stratification. Hepatorenal syndrome (HRS) is a unique form of AKI developing in patients with end-stage liver disease. Systemic circulatory dysfunction and marked kidney vasoconstriction play a key role in the development of HRS. The modification of the definition of AKI has also led to a change in the diagnostic criteria of HRS. The new diagnostic criteria are based on AKI stages and there is no need to reach a specific serum creatinine threshold. According to these new criteria, treatment with vasoconstrictors and albumin for the management of HRS will be started at lower serum creatinine values, with expected higher response rates. Finally, there are consistent data showing that some urine biomarkers, particularly NGAL (neutrophil gelatinase-associated lipocalin), may be useful in daily clinical practice for the differential diagnosis of the cause of AKI in cirrhosis.

A novel scoring model for predicting mortality risk in patients with cirrhosis and hepatorenal syndrome.

BACKGROUND AND AIMS: This study aimed to create a risk scoring model for death from cirrhosis and hepatorenal syndrome, improve the detection rate of high-risk groups, and provide clinical evidence for early intervention treatment. PATIENTS AND METHODS: We retrospectively recruited 196 patients with cirrhosis and hepatorenal syndrome between 1 January 2013 and 31 July 2014 at Beijing Ditan Hospital, Capital Medical University, China. The clinical information, biochemical values, age, and sex of the patients were included in the multivariate logistic regression model for screening independent risk factors. The model was validated in 56 patients with cirrhosis and hepatorenal syndrome between 1 August 2014 and 31 December 2014 at Beijing Ditan Hospital, Capital Medical University, China. RESULTS: The death risk prediction scoring model included the following four independent risk factors: liver cancer, neutrophil above 70%, alanine aminotransferase higher than 40 U/l, and creatinine higher than 127 mmol/l. The sum death risk score ranged from 0 to 5: 0-2 identified patients with a lower risk of death (mortality rates: 12-41.4%), whereas 3-5 identified patients with a higher risk of death (mortality rates: 48.8-80%). Receiver-operating characteristic curves were constructed for the scoring model and the areas under the curves (AUC) were compared using the z-test. The AUC of the scoring model was 0.843. In addition, the AUC of validated model in 56 patients was 0.742. CONCLUSION: The scoring model can accurately predict mortality risk in patients with hepatorenal syndrome.

New Developments in Hepatorenal Syndrome.

Hepatorenal syndrome (HRS) continues to be one of the major complications of decompensated cirrhosis, leading to death in the absence of liver transplantation. Challenges in precisely evaluating renal function in the patient with cirrhosis remain because of the limitations of serum creatinine (Cr) alone in estimating glomerular filtration rate (GFR); current GFR estimating models appear to underestimate renal dysfunction. Newer models incorporating renal biomarkers, such as the Cr-Cystatin C GFR Equation for Cirrhosis appear to estimate measured GFR more accurately. A major change in the diagnostic criteria for HRS based on dynamic serial changes in serum Cr that regard HRS type 1 as a special form of acute kidney injury promises the possibility of earlier identification of renal dysfunction in patients with cirrhosis. The diagnostic criteria of HRS still include the exclusion of other causes of kidney injury. Renal biomarkers have been disappointing in assisting with the differentiation of HRS from prerenal azotemia and other kidney disorders. Serum metabolomic profiling may be a more powerful tool to assess renal dysfunction, although the practical clinical significance of this remains unclear. As a result of the difficulties of assessing renal function in cirrhosis and the varying HRS diagnostic criteria and the rigor with which they are applied, the precise incidence and prevalence of HRS is unknown, but it is likely that HRS occurs more commonly than expected. The pathophysiology of HRS is rooted firmly in the setting of progressive reduction in renal blood flow as a result of portal hypertension and splanchnic vasodilation. Progressive marked renal cortical ischemia in patients with cirrhosis parallels the evolution of diuretic-sensitive ascites to diuretic-refractory ascites and HRS, a recognized continuum of renal dysfunction in cirrhosis. Alterations in nitrous oxide production, both increased and decreased, may play a major role in the pathophysiology of this evolution. The inflammatory cascade, triggered by bacterial translocation and endotoxemia, increasingly recognized as important in the manifestation of acute-on-chronic liver failure, also may play a significant role in the pathophysiology of HRS. The mainstay of treatment remains vasopressor therapy with albumin in an attempt to reverse splanchnic vasodilation and improve renal blood flow. Several meta-analyses have confirmed the value of vasopressors, chiefly terlipressin and noradrenaline, in improving renal function and reversing HRS type 1. Other interventions such as renal replacement therapy, transjugular intrahepatic portosystemic shunt, and artificial liver support systems have a very limited role in improving outcomes in HRS. Liver transplantation remains the definitive treatment for HRS. The frequency of simultaneous liver-kidney transplantation has increased dramatically in the Model for End-stage Liver Disease era, with changes in organ allocation policies. This has resulted in a more urgent need to predict native kidney recovery from HRS after liver transplantation alone, to avoid unnecessary simultaneous liver-kidney transplantation.

Renal dysfunction and cirrhosis.

PURPOSE OF REVIEW: Hepatorenal syndrome (HRS) does not represent the predominant phenotype of acute kidney injury (AKI) in cirrhosis. Early recognition of HRS helps initiate appropriate therapy. The aims of this review are to present redefinition of AKI, to list new biomarkers, to report recent data on vasopressors in HRS and to propose criteria for simultaneous liver and kidney transplantation (SLKT). RECENT FINDINGS: Urine output, which was not part of the definition of AKI might be reconsidered as it has an independent prognostic value. Biomarkers (NGAL and IL-18) could help identify ATN. However, cut-off values have to be clarified. Vasopressors with albumin represent first option in HRS. Continuous infusion of terlipressin has a better safety profile than intravenous boluses. SLKT should be considered whenever native kidney recovery is unlikely [i.e. prolonged renal replacement therapy (RRT) and/or GFR less than 25 ml/min for 6 weeks prior to transplantation]. SUMMARY: New definitions and recent biomarkers may help differentiate HRS from ATN at an earlier stage. Urine output should be reconsidered in the definitions. Even in patients who are not candidates for transplantation, a short trial of RRT is justified whenever needed. SLKT should be considered whenever posttransplant renal recovery is unlikely.

Dual Organ Duel: The Hepatorenal Axis.

Recent developments in our understanding of the pathogenesis of kidney disease in the setting of liver failure have highlighted that kidney injury, rather than occurring in isolation, is a marker of systemic disease and poor prognosis. The differential diagnosis of kidney disease associated with liver failure is broader than formerly described and new biopsy data, along with better acute kidney injury classification tools, have increased appreciation for distinct pathophysiological mechanisms. Evidence suggests that acute kidney injury contributes to worsening hepatic failure by directly injuring hepatic cells and by imposing restrictions on therapeutic strategies for portal hypertension. Furthermore, kidney injury limits the use of various therapeutic agents and increases their toxicity due to altered pharmacodynamics. A greater appreciation of CKD in this population is also overdue because management decisions are affected and increased vigilance may avoid further kidney injury. A multidisciplinary approach to kidney injury in the setting of liver failure will enable targeted therapeutic strategies that are safe and effective and serve to guide further research, while limiting clinical potential for harm. Finally, new hepatitis C antiviral therapies promise to change the landscape of liver failure, and a discussion of kidney risk factors and antiviral therapy of patients with kidney disease and hepatitis C is worthwhile.