Serum sodium, renal function, and survival of patients with end-stage liver disease

Effect of long-term serum sodium levels on the prognosis of patients on maintenance hemodialysis

Abnormal serum Na (SNa) levels are common in patients with chronic kidney disease (CKD) which is associated with increased morbidity and mortality. There are relatively few studies on the effect of SNa indicators on the prognosis of patients undergoing maintenance hemodialysis (MHD). We aim to investigate the effect of long-term SNa levels on the survival and prognosis of patients undergoing hemodialysis (HD). Newly entered HD patients in the registration system of Zhejiang Provincial Dialysis Quality Control Center between January 1, 2010 and December 31, 2019 were included and followed up until December 31, 2020. Multiple sodium levels were collected from patients, defining long-term SNa as the mean of multiple SNa, according to which patients were grouped, with the prognostic differences between subgroups compared by Kaplan-Meier modeling and multifactorial Cox regression modeling. Finally, a total of 21,701 patients were included in this study and Cox regression showed that decreased SNa levels (Na < 135 mmol/L, HR = 1.704, 95% CI 1.408-2.063, p < 0.001; 135≦Na≦137.5 mmol/L, HR = 1.127,95% CI 1.016-1.250, p = 0.024) and elevated SNa levels (142.5 < Na≦145mmol/L, HR = 1.198, 95% CI 1.063-1.350, p = 0.003; Na > 145mmol/L, HR = 2.150, 95% CI 1.615-2.863, p < 0.001) were all independent risk factors for all-cause mortality in MHD patients.

Assessment of the 2021 AASLD Practice Guidance for Albumin Infusion in Elective Therapeutic Paracentesis: A Regression Discontinuity Design

INTRODUCTION

The 2021 American Association for the Study of Liver Disease (AASLD) Practice Guidance recommends albumin infusion when removing ≥5 L of ascites to prevent post-paracentesis circulatory dysfunction. However, the optimal criteria and scenarios for initiating albumin infusion subsequent to therapeutic paracentesis (TP) have been subject to limited scientific inquiry.

METHODS

We conducted a retrospective cohort study at a US academic healthcare center. Participants received elective, outpatient TP between July 2019 and December 2022. Patients with spontaneous bacterial peritonitis, post-TP clinical adjustments, and/or hospitalization were excluded. The institution strictly followed the AASLD Guidance. We used a sharp regression discontinuity (RD) design to estimate the effect of albumin infusion at the AASLD Guidance-recommended cutoff of 5 L on serum creatinine and sodium trajectory after TP.

RESULTS

Over the study period, 1,457 elective TPs were performed on 235 unique patients. Albumin infusion at the threshold of 5 L of ascites removal reduced serum creatinine levels by 0.046 mg/dL/d (95% confidence interval 0.003-0.116, P = 0.037) and increased serum sodium levels by 0.35 mEq/L/d (95% confidence interval 0.15-0.55, P = 0.001) compared with those who did not receive albumin infusion. The RD plots indicated worsened serum creatine/sodium levels after draining 3 L of fluid, approaching levels similar to or worse than with albumin infusion at 5 L or more.

DISCUSSION

Our RD models supported the 2021 AASLD Guidance with robust estimation of causal effect sizes at the cutoff level of 5 L. Nevertheless, the findings also highlight the need to further evaluate the efficacy of albumin infusion in patients who undergo elective TP and have 3-5 L of ascites removed.

Update on Assessment of Estimated Glomerular Filtration Rate in Patients With Cirrhosis

Kidney disease is associated with adverse outcomes in patients with cirrhosis including increased post-liver transplantation (LT) mortality. Therefore, diagnosis and staging of kidney disease are critical to timely implementation of treatment and have important implications for transplant eligibility. Serum creatinine (sCr) is a key component of the Model for End-Stage Liver Disease score in LT candidates, and sCr-based estimated glomerular filtration rate (eGFR) values play an important role in determining medical urgency for LT. However, the use of sCr to assess kidney function may be limited in the cirrhotic milieu due to decreased creatinine production, interference of bilirubin with some laboratory assays for sCr, and expansion of the volume of distribution of creatinine. Therefore, conventional eGFR equations perform poorly in patients with cirrhosis and may overestimate kidney function leading to delayed diagnosis of acute kidney injury or lower priority for LT in patients with a truly low glomerular filtration rate. In this review, we will provide an update on the use of sCr for diagnosis and staging of kidney disease in patients with cirrhosis, discuss the limitations of sCr-based eGFR equations, and discuss novel eGFR equations that have been developed in patients with cirrhosis.

Assessment of glomerular filtration rate in patients with cirrhosis: Available tools and perspectives

Renal dysfunction often complicates the course of liver disease, resulting in higher morbidity and mortality. The accurate assessment of kidney function in these patients is essential to early identify, stage and treat renal impairment as well as to better predict the prognosis, prioritize the patients for liver transplantation and decide whether to opt for simultaneous liver-kidney transplants. This review analyses the available tools for direct or indirect assessment of glomerular filtration rate, focusing on the flaws and strengths of each method in the specific setting of cirrhosis. The aim is to deliver a clear-cut view on this complex issue, trying to point out which strategies to prefer in this context, especially in the peculiar setting of liver transplantation. Moreover, a glance is given at future promising tools for glomerular filtration rate assessment, including new biomarkers and new equations specifically modelled for the cirrhotic population.

Estimated glomerular filtration rate by formulas in patients with cirrhosis: An unreliable procedure

BACKGROUND & AIMS

In cirrhosis, the reliability of formulas that estimate renal function, either those specifically developed in this population or the classic equations, has not been properly quantified. We studied the agreement between estimated (eGFR) and measured glomerular filtration rate (mGFR) in cirrhosis.

METHODS

Renal function was estimated with 56 formulas including specific equations: Glomerular Filtration Rate Assessment in Liver Disease (GRAIL), Royal Free Hospital Cirrhosis (RFHC) and Mindikoglu-eGFR, and measured with a gold standard procedure; plasma clearance of iohexol using dried blood spots sampling in a group of cirrhotics. The agreement eGFR-mGFR was evaluated with specific tests: total deviation index (TDI), concordance correlation coefficient (CCC) and coverage probability (CP). We defined acceptable agreement as values: TDI < 10%, CCC ≥ 0.9 and CP > 90%.

RESULTS

A total of 146 patients (age 65 ± 9 years, 81% male) were evaluated; 61 (42%) Child A, 67 (46%) Child B and 18 (12%) Child C. Median MELD-Na was 14 (9-15). The agreement between eGFR and mGFR was poor: TDI averaged was of 73% (90% of the estimations ranged from ±73% of mGFR); CCC averaged was 0.7 indicating low concordance and CP averaged 22% indicating that 78% of the estimations have an error > 10%. Specific formulas showed also poor agreement: TDI was 82%, 70% and 37% for the GRAIL, RFHC and Mindikoglu equations, respectively.

CONCLUSIONS

Overall, formulas poorly estimated renal function in cirrhotic patients. Specific formulas designed for cirrhosis did not outperform classic equations. eGFR must be considered with caution in cirrhotic patients.

Gender disparities in transplantation

PURPOSE OF REVIEW

Transplantation is the life-saving therapy for patients suffering from end-organ failure, and as such, equitable access to transplantation (ATT) is of paramount importance. Unfortunately, gender/sex-based disparities exist, and despite the transplant community's awareness of this injustice, gender/sex-based disparities have persisted for more than two decades. Importantly, no legislation or allocation policy has addressed inequity in ATT that women disproportionately face. In fact, introduction of the model for end-stage liver disease-based liver allocation system in 2002 widened the gender disparity gap and it continues to be in effect today. Moreover, women suffering from kidney disease are consistently less likely to be referred for transplant evaluation and subsequently less likely to achieve a kidney transplant, yet they comprise the majority of living kidney donors.

RECENT FINDINGS

Acknowledging gender/sex-based disparities in ATT is the first step toward interventions aimed at mitigating this long-standing injustice in healthcare.

SUMMARY

This article provides a background of end-stage liver and kidney disease in women, summarizes the existing literature describing the issue of gender disparity in ATT, and identifies potential areas of intervention and future investigation.

New prognostic score based on galectin-3 has similar performance to model for end-stage liver disease and sodium score in patients with stable decompensated cirrhosis

Background

Galectin-3 (gal-3) has been proposed as a marker of established renal impairment, with predictive value in stable decompensated cirrhosis.

Methods

150 stable decompensated patients were assessed in 2 transplant centers. Patients' renal function was assessed using ⁵¹Chromium-EDTA ("true" glomerular filtration rate). We measured basic laboratory variables and gal-3 in serum samples. Factors associated with patients' outcomes were determined.

Results

Our patients were followed up for 12 months (range 1-48, interquartile range [IQR] 6, 95% confidence interval [CI] 10-13.5) and their mean prognostic scores were Child-Turcotte-Pugh (CTP) 7±2 and model for end-stage liver disease and sodium (MELD-Na) 15±6. Median gal-3 levels were 22 ng/mL. In a multivariate analysis of 94 patients (training group), gal-3 (hazard ratio [HR] 1.026, 95% confidence interval [CI] 1.011-1.041; P=0.003) and serum sodium (HR 1.032, 95%CI 1.006-1.062; P=0.05) were the only factors independently associated with patients' outcomes. Kaplan-Meier analysis using the median gal-3 values revealed different times of survival (log-rank P=0.006). We derived a new prognostic score, (0.026) × serum gal-3+ (-0.079) × serum sodium, with very good discriminative accuracy for the outcome (area under the curve [AUC] 0.71, 95%CI 0.63-0.88), similar to that of the MELD-Na score (AUC 0.69, 95%CI 0.67-0.89; P=0.73), while its diagnostic accuracy was validated in the remaining 56 decompensated patients (AUC 0.81, 95%CI 0.65-0.97).

Conclusions

Gal-3 proved to be an accurate and plausible biomarker of renal dysfunction in patients with decompensated cirrhosis. A new prognostic model incorporating gal-3 and sodium was derived, with very good discriminative accuracy for the outcome.

Obesity is a risk factor for progression to kidney transplant waitlisting after liver transplantation

BACKGROUND

Non-alcoholic steatohepatitis has emerged as a leading cause of cirrhosis, and obesity-associated comorbidities, including renal disease, have increased in prevalence. Obesity predisposes the kidney to hyperfiltration injury, potentially impairing acute kidney injury recovery. Identification of patients at risk for renal dysfunction is impeded by poor performance of renal function estimating equations among cirrhotics. To better understand obesity among cirrhotics and renal disease progression, we examined likelihood of kidney transplantation (KT) waitlisting after liver transplant alone (LTA) by obesity class.

METHODS

68 607 LTA recipients were identified in SRTR (2005-2018). Fine and Gray competing risks models were used to analyze likelihood of KT waitlisting.

RESULTS

27.4% of recipients were obese (BMI ≥ 30 kg/m² ) and were 10% more likely to require KT waitlisting (aHR: 1.10, 95%CI: 1.01-1.20). Risk was highest among recipients with Classes II and III obesity (BMI: ≥35 kg/m² ) (aHR: 1.37, 95%CI: 1.17-1.56). Moreover, recipients with Classes II and III obesity were 57% more likely to require KT waitlisting within one year post-LTA (aHR: 1.57, 95%CI: 1.18-2.10) compared to non-obese recipients.

DISCUSSION

These findings suggest obesity was a risk factor for renal recovery failure and/or renal disease progression post-LTA and may confound identification of renal dysfunction and/or prediction of renal recovery among cirrhotics.

Renal disease in the allograft recipient

Chronic renal failure after liver transplantation (LT) is significantly more frequent than after lung or heart transplantation and it results in an increased short and long-term mortality. Renal impairment may occur before LT (functional or due to preexisting parenchymal kidney disease), in the peri-operative period or later after LT. The number of patients with renal failure after LT has increased due to the liver allocation based on MELD and to the more liberal use of higher risk grafts. Calcineurin inhibitor (CNI) nephrotoxicity is the most important cause of renal dysfunction but is a modifiable factor. Strategy to prevent CNI-associated nephrotoxicity is post-op CNI minimization by induction therapy and reduced dose and/or delayed introduction of CNI in combination with mycophenolate mofetil (MMF) or everolimus with no penalty in term of rejection. With everolimus, usually started one month after LT, a drastic minimization of CNI is possible and this results in superior kidney function until at least 3 years follow up. At the moment of renal impairment a drastic reduction of CNI dose together with the introduction of MMF results in an improvement in GFR at 6 to 2 years with a low rate of acute rejection. However, secondary prevention fails to normalize renal function in most of the patients once e GFR <60 ml/min/1.73m²ml.

Prevalence of Acute Kidney Injury in Patients with Liver Cirrhosis

Introduction:

Acute kidney injury is a common and life-threatening event in patients with liver cirrhosis occurring in approximately 20-50% of hospitalized patients of liver cirrhosis. Pre-renal acute kidney injury, the hepatorenal syndrome type of acute kidney injury and acute tubular necrosis represent the common causes. The aim of this study was to study the profile of acute kidney injury in patients with liver cirrhosis.

Methods:

Consecutive patients of liver cirrhosis admitted in Liver unit of Bir Hospital were studied to see the presence of acute kidney injury in this hospital based descriptive cross-sectional study. Clinical and laboratory parameters along with various clinical outcome were compared between different groups categorized by the severity of liver disease and renal dysfunction.

Results:

Out of 302 liver cirrhosis patients, 56 (18.5%) had acute kidney injury among which 23 (46%) were found to have pre-renal acute kidney injury, 15 (30%) with hepatorenal syndrome-acute kidney injury and 12 (24%) with intrinsic renal disease. Patients with higher stages of acute kidney injury had longer duration of hospital stay and hepatorenal syndrome-acute kidney injury was seen in patients with higher grade of ascites and with hyponatremia.

Conclusion:

Acute kidney injury is a common occurrence in patients with advanced liver cirrhosis with pre-renal acute kidney injury being the commonest cause. Median hospital stay is directly affected by the severity of acute kidney injury and hepatorenal syndrome-acute kidney injury was seen in patients with higher grade of ascites and hyponatremia. Early identification of patients at high risk for acute kidney injury may help to reduce mortality and contain costs.

MELD-GRAIL-Na: Glomerular Filtration Rate and Mortality on Liver-Transplant Waiting List

BACKGROUND AND AIMS

Among patients with cirrhosis awaiting liver transplantation, prediction of wait-list (WL) mortality is adjudicated by the Model for End Stage Liver Disease-Sodium (MELD-Na) score. Replacing serum creatinine (SCr) with estimated glomerular filtration rate (eGFR) in the MELD-Na score may improve prediction of WL mortality, especially for women and highest disease severity.

APPROACH AND RESULTS

We developed (2014) and validated (2015) a model incorporating eGFR using national data (n = 17,095) to predict WL mortality. Glomerular filtration rate (GFR) was estimated using the GFR assessment in liver disease (GRAIL) developed among patients with cirrhosis. Multivariate Cox proportional hazard analysis models were used to compare the predicted 90-day WL mortality between MELD-GRAIL-Na (re-estimated bilirubin, international normalized ratio [INR], sodium, and GRAIL) versus MELD-Na. Within 3 months, 27.8% were transplanted, 4.3% died on the WL, and 4.7% were delisted for other reasons. GFR as estimated by GRAIL (hazard ratio [HR] 0.382, 95% confidence interval [CI] 0.344-0.424) and the re-estimated model MELD-GRAIL-Na (HR 1.212, 95% CI 1.199-1.224) were significant predictors of mortality or being delisted on the WL within 3 months. MELD-GRAIL-Na was a better predictor of observed mortality at highest deciles of disease severity (≥ 27-40). For a score of 32 or higher (observed mortality 0.68), predicted mortality was 0.67 (MELD-GRAIL-Na) and 0.51 (MELD-Na). For women, a score of 32 or higher (observed mortality 0.67), the predicted mortality was 0.69 (MELD-GRAIL-Na) and 0.55 (MELD-Na). In 2015, use of MELD-GRAIL-Na as compared with MELD-Na resulted in reclassification of 16.7% (n = 672) of patients on the WL.

CONCLUSION

Incorporation of eGFR likely captures true GFR better than SCr, especially among women. Incorporation of MELD-GRAIL-Na instead of MELD-Na may affect outcomes for 12%-17% awaiting transplant and affect organ allocation.

A Model for Glomerular Filtration Rate Assessment in Liver Disease (GRAIL) in the Presence of Renal Dysfunction

Estimation of glomerular filtration rate (eGFR) in patients with liver disease is suboptimal in the presence of renal dysfunction. We developed a model for GFR assessment in liver disease (GRAIL) before and after liver transplantation (LT). GRAIL was derived using objective variables (creatinine, blood urea nitrogen, age, gender, race, and albumin) to estimate GFR based on timing of measurement relative to LT and degree of renal dysfunction (www.bswh.md/grail). The measured GFR (mGFR) by iothalamate clearance (n = 12,122, 1985-2015) at protocol time points before/after LT was used as reference. GRAIL was compared with the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and Modification of Diet in Renal Disease (MDRD-4, MDRD-6) equations for mGFR < 30 mL/min/1.73 m² . Prediction of development of chronic kidney disease (mGFR < 20 mL/min/1.73 m² , initiation of chronic dialysis) and listing or receipt of kidney transplantation within 5 years was examined in internal cohort (n = 785) and external validation (n = 68,217, 2001-2015). GRAIL had less bias and was more accurate and precise as compared with CKD-EPI, MDRD-4, and MDRD-6 at time points before/after LT for low GFR. For mGFR < 30 mL/min/1.73 m² , the median difference (eGFR-mGFR) was GRAIL: 5.24 (9.65) mL/min/1.73 m² as compared with CKD-EPI: 8.70 (18.24) mL/min/1.73 m² , MDRD-4: 8.82 (17.38) mL/min/1.73 m² , and MDRD-6: 6.53 (14.42) mL/min/1.73 m² . Before LT, GRAIL correctly classified 75% as having mGFR < 30 mL/min/1.73 m² versus 36.1% (CKD-EPI), 36.1% (MDRD-4), and 52.8% (MDRD-6) (P < 0.01). An eGFR < 30 mL/min/1.73 m² by GRAIL predicted development of CKD (26.9% versus 4.6% CKD-EPI, 5.9% MDRD-4, and 10.5% MDRD-6) in center data and needing kidney after LT (48.3% versus 22.0% CKD-EPI versus 23.1% MDRD-4 versus 48.3% MDRD-6, P < 0.01) in national data within 5 years after LT. Conclusion: GRAIL may serve as an alternative model to estimate GFR among patients with liver disease before and after LT at low GFR.

Correlation Between MELD and UNa/K Ratio in Predicting Renal Dysfunction in Cirrhotic Patients

Background

Renal dysfunction is one of the dreaded complications of cirrhosis. MELD is a validated chronic liver disease (CLD) severity scoring system. Urinary (U) Na/K ratio closely correlates with renal dysfunction in terms of low GFR in cirrhotic patients.

Patients and Methods

All consecutive patients with decompensated cirrhosis between the age of 18 to 70 years, of either gender, presenting in the outpatients’ department of Sindh Institute of Urology and Transplantation, Karachi, from June 2015 to June 2017 were included. The MELD score was calculated and the UNa/K ratio less than 1 was taken as surrogate marker of renal dysfunction. Statistical analysis was performed by SPSS (version 20.0).

Results

A total of 71 patients were enrolled. The mean age was 43.79 years and majority were male (67.6%). The most common cause of liver cirrhosis was HCV, found in 42 (59.2%) patients. The mean CTP score was 10.48 ± 2.069 (range: 6–14) with majority of the patients following in class C, that is, 48 (67.6%). Mean MELD score was 21.75 ± 8.96 (range: 8–43). In 57 patients (80.3%), MELD score was > 15.The mean serum creatinine and mean serum sodium were 1.5 ± 1.1 mg/dl (range: 0.37–5.3) and 133.79 ± 6.9 mmol/L (range: 112–152), respectively. Mean urinary sodium and urinary potassium were 38.60 ± 46.64 mmol/L (range: 5–181) and 38.15 ± 23.9 mmol/L (range: 4.3–112), respectively. In majority of study population, UNa/K ratio was below 1, that is, in 52 patients (73.2%). Statistically significant correlation was documented between MELD score and UNa/K ratio (ɤ = 0.34, P = 0.004).

Conclusion

The inverse correlation between MELD scores and UNa/K ratio indicates that patients with CLD and higher MELD scores might have renal dysfunction. This finding however should be corroborated by large scale studies.

Adefovir dipivoxil-induced Fanconi syndrome and its predictive factors: A study of 28 cases

The aim of the present study was to identify monitoring and prevention measures as well as predictive factors for early detection of renal toxicity associated with long-term administration of adefovir dipivoxil in order to avoid progression to Fanconi syndrome. Clinical data of 28 patients with Fanconi syndrome caused by long-term administration of adefovir dipivoxil for the treatment of chronic hepatitis B virus (HBV) infection were collected pre-and post-administration for analysis. Patients presented with fatigue, progressive systemic pain in multiple bones and joints, as well as difficulty in walking and pathological fractures in a number of severe cases. Laboratory examinations revealed hypophosphatemia, elevated serum cystatin C (Cys-C), elevated serum creatinine (SCr), reduced glomerular filtration rate (GFR), positive urinary protein, erythrocytes and glucose, as well as osteoporosis. In consequence, adefovir dipivoxil administration was stopped, and patients received concentrated divitamins, sodium phosphate syrup and calcitriol. Symptoms and abnormalities in laboratory examinations were significantly improved in all patients after 2-6 months. Therefore, serum phosphate, SCr, routine urine parameters, Cys-C and GFR should be monitored regularly in chronic HBV patients treated with adefovir dipivoxil. The following factors were identified as predictive of kidney damage and Fanconi syndrome: Age ≥40 years, living in rural areas, previous renal toxicity, estimated GFR (eGFR) <90 ml/min/1.73 m², hypertension, diabetes, cirrhosis and duration of adefovir dipivoxil treatment exceeding 24 months. The present results indicate that timely termination of adefovir dipivoxil treatment and replacement with other antiviral agents is critical once renal impairment appears, and that it is necessary to change to other antiviral agents and prolong the interval of administration according to the eGFR level.

Acute renal injury after partial hepatectomy

Currently, partial hepatectomy is the treatment of choice for a wide variety of liver and biliary conditions. Among the possible complications of partial hepatectomy, acute kidney injury (AKI) should be considered as an important cause of increased morbidity and postoperative mortality. Difficulties in the data analysis related to postoperative AKI after liver resections are mainly due to the multiplicity of factors to be considered in the surgical patients, moreover, there is no consensus of the exact definition of AKI after liver resection in the literature, which hampers comparison and analysis of the scarce data published on the subject. Despite this multiplicity of risk factors for postoperative AKI after partial hepatectomy, there are main factors that clearly contribute to its occurrence. First factor relates to large blood losses with renal hypoperfusion during the operation, second factor relates to the occurrence of post-hepatectomy liver failure with consequent distributive circulatory changes and hepatorenal syndrome. Eventually, patients can have more than one factor contributing to post-operative AKI, and frequently these combinations of acute insults can be aggravated by sepsis or exposure to nephrotoxic drugs.

Impact of dynamic changes in MELD score on survival after liver transplantation - a Eurotransplant registry analysis

BACKGROUND & AIMS

With restricted numbers of available organs, futility in liver transplantation has to be avoided. The concept of dynamic changes in MELD score (DeltaMELD) has previously been shown to be a simple tool to identify patients with the greatest risk of death after transplantation. Aim was to validate this concept with the Eurotransplant (ET) database.

METHODS

A retrospective registry analysis was performed on all patients listed for liver transplantation within ET between 2006 and 2011. Patients <18 years of age, acute liver failure, malignancy and patients listed for retransplantation were excluded. Influence of MELD at listing (MELDon), MELD at transplantation (MELDoff), DeltaMELD, age, sex, underlying disease and time on the waiting list on overall survival after liver transplantation were evaluated.

RESULTS

A total of 16 821 patients were listed for liver transplantation, 8096 met the inclusion criteria. Age, MELD on and DeltaMELD showed significant influence on survival on the waiting list. Age and DeltaMELD showed influence on survival after liver transplantation, with DeltaMELD>10 showing a 1.6-fold increased risk of death.

CONCLUSION

The concept of DeltaMELD was validated in a large, prospective data set. It provides a simple tool to identify patients with increased risk of death after liver transplantation and might help improve long-term results.

New ICA criteria for the diagnosis of acute kidney injury in cirrhotic patients: can we use an imputed value of serum creatinine?

BACKGROUND & AIMS

The new International Club of Ascites diagnostic criteria to diagnose acute kidney injury at hospital admission suggests the possibility of using a presumed baseline serum creatinine, defined as the last of at least two stable creatinine values during the last 3 months. Nevertheless, the possibility of the lack of such a value still remains. In these patients, the KDIGO criteria suggest to use an inverse application of MDRD equation assuming that baseline glomerular filtration rate is 75 ml/min per 1.73 m(2) (imputed baseline creatinine). We tested the accuracy of this approach to detect acute kidney injury at admission in patients with decompensated cirrhosis and creatinine <1.5 mg/dl.

METHODS

We analysed 213 patients hospitalized for acute decompensation of cirrhosis. At admission, glomerular filtration rate was estimated using creatinine-based equations and measured by inulin clearance. A diagnosis of acute kidney injury was made using an imputed value of serum creatinine as baseline.

RESULTS

The diagnosis of AKI based on an imputed baseline creatinine identified only 20.1% of patients with measured glomerular filtration rate ≤60 ml/min/1.73 m(2) without any predictive value on 90-day survival.

CONCLUSIONS

In patients with cirrhosis and ascites with a creatinine <1.5 mg/dl without a baseline value on their records, the diagnosis of acute kidney injury at admission based on an imputed baseline creatinine is not accurate.

Model for end-stage liver disease score and MELD exceptions: 15 years later

The model for end-stage liver disease (MELD) score has been used as an objective scale of disease severity for management of patients with end-stage liver disease; it currently serves as the basis of an urgency-based organ-allocation policy in several countries. Implementation of the MELD score led to a reduction in waiting-list registration and waiting-list mortality and an increase in the number of deceased-donor transplants without adversely affecting long-term outcomes after liver transplantation (LT). The MELD score has been used for management of non-transplant patients with chronic liver disease. MELD exceptions serve as a mechanism to advance the needs of subsets of patients with liver disease not adequately addressed by MELD-based organ allocation. Several models have been proposed to refine and improve the MELD score as the environment within which it operates continues to evolve toward transplantation for sicker patients. The MELD score continues to serve and be used as a template to improve upon as an objective gauge of disease severity and as a metric enabling optimization of allocation of scarce donor organs for LT.

Prognostic Significance of the Systemic Inflammatory and Immune Balance in Alcoholic Liver Disease with a Focus on Gender-Related Differences

Objectives

Mechanisms of immune regulation in alcoholic liver disease (ALD) are still unclear. The aim of our study was to determine an impact of Th17 / regulatory T (Treg) cells balance and its corresponding cytokine profile on the ALD outcome. Possible gender-related differences in the alcohol-induced inflammatory response were also assessed.

Materials and Methods

147 patients with ALD were prospectively recruited, assigned to subgroups based on their gender, severity of liver dysfunction and presence of ALD complications at admission, and followed for 90 days. Peripheral blood frequencies of Th17 and Treg cells together with IL-1beta, IL-6, IL-17A, IL-23, and TGF-beta1 levels were investigated. Flow cytometry was used to identify T cell phenotype and immunoenzymatic ELISAs for the corresponding cytokine concentrations assessment. Multivariable logistic regression was applied in order to select independent predictors of advanced liver dysfunction and the disease complications.

Results

IL-17A, IL-1beta, IL-6 levels were significantly increased, while TGF-beta1 decreased in ALD patients. The imbalance with significantly higher Th17 and lower Treg frequencies was observed in non-survivors. IL-6 and TGF-beta1 levels differed in relation to patient gender in ALD group. Concentrations of IL-6 were associated with the severity of liver dysfunction, development of ALD complications, and turned out to be the only independent immune predictor of 90-day survival in the study cohort.

Conclusions

We conclude that IL-6 revealed the highest diagnostic and prognostic potential among studied biomarkers and was related to the fatal ALD course. Gender-related differences in immune regulation might influence the susceptibility to alcohol-associated liver injury.

Gender-based disparities in access to and outcomes of liver transplantation

Despite comprising 35% of transplants, the number of female transplant recipients has continued to decline. Accordingly, there is a growing attention to the issue of access to and outcomes of liver transplantation in women. The purpose of this review is to critically evaluate the published literature on etiologies contributing to gender-based disparities in liver transplantation focusing on the steps from chronic liver disease through transplantation including disparities in liver disease prevalence, access to liver transplant centers and transplant waiting list, receipt of liver transplantation once listed and disparities in post-liver transplantation outcomes. Our review finds factors contributing to this disparity may include gender differences in the etiology of underlying liver disease and patient and physician referral patterns, lifestyle and health care, but also utilization of an imperfect organ allocation system based on the model for end stage liver disease score and donor-recipient liver size matching. The review also highlights the need for further research in the area of gender disparity in order to develop appropriate approaches to address it and to improve allocation of this precious resource in the future.

Accuracy of urine collection methods compared to measured GFR in adults with liver disease

BACKGROUND

Assessment of kidney function is necessary to stage kidney disease, dose medications, and to make decisions about organ allocation. Estimating equations that incorporate serum creatinine (SCr) are not consistently reliable. However, assessment of creatinine clearance (CrCl) using 24-hour urine collection methods is also prone to errors. The purpose of this study was to evaluate the accuracy of measured CrCl determined using shorter urine collection times compared to glomerular filtration rate measured by (125)I-iothalamate clearance ((125)I-CL) in patients with liver disease.

METHODS

Adult patients with chronic liver disease were enrolled. All patients received (125)I-iothalamate and had a catheter placed for urine collection. Blood samples were collected at designated times over 8 hours to determine (125)I-CL. CrCl was determined from a 1-hour and a 4-hour urine collection and compared to (125)I-CL.

RESULTS

Characteristics of the eight patients enrolled included age 52 ± 6 years; SCr 1.2 ± 0.4 mg/dL; and Model for End-stage Liver Disease score of 13 ± 3. All patients were Child-Pugh Class B. Mean estimates of kidney function (mean ± SD, mL/min/1.73 m(2)) by method were 74 ± 38 for (125)I-CL, 79 ± 28 for the 1-hour urine collection, and 72 ± 26 for the 4-hour urine collection. Measured CrCl did not differ significantly from (125)I-CL (P = .641 for 1-hour CrCl versus (125)I-CL, and P = 1.0 for the 4-hour CrCl versus (125)I-CL).

CONCLUSION

When urine collection methods are necessary for an individualized assessment of kidney function, shorter collection times can provide accurate results and would be more feasible for the patient.

Glomerular filtration rate is an independent factor of mortality in patients with decompensated cirrhosis

AIM

Although serum creatinine is included in the Model for End-Stage Liver Disease (MELD) score, it is an inaccurate marker of renal function, namely, of glomerular filtration rate ("true" GFR) in patients with decompensated cirrhosis. Our aim was to investigate the impact of MELD score and "true" GFR as determinants of survival in patients with decompensated cirrhosis.

METHODS

We included all consecutive patients with decompensated cirrhosis who were admitted to our department. Renal function was assessed by creatinine- and cystatin-based estimated GFR and "true" GFR using (51) Cr-ethylenediaminetetraacetic acid. The independent factors associated with survival were evaluated. The discriminative ability of the prognostic scores (MELD and modifications of MELD score) were evaluated by using the area under the receiver-operator curve (AUC).

RESULTS

One hundred and ten consecutive patients (77 men, aged 56 ± 12 years); at the end of follow up (8 months; range, 6-18), 92 patients (84%) were alive and 18 (16%) had died. In multivariate analysis, serum bilirubin (hazard ratio [HR], 1.15; 95% confidence interval [CI], 1.05-1.26; P = 0.020) and "true" GFR (HR, 0.96; 95% CI, 0.93-0.98; P = 0.003) were the only independent factors significantly associated with the outcome. The derived new prognostic model had high discriminative ability (AUC, 0.90), which was confirmed in the validation sample of 77 patients.

CONCLUSION

In our cohort of patients with decompensated cirrhosis, "true" GFR and bilirubin were the independent factors of the outcome.

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

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

Prevalence of renal dysfunction in patients with cirrhosis according to ADQI-IAC working party proposal

BACKGROUND/AIMS

A revised classification system for renal dysfunction in patients with cirrhosis was proposed by the Acute Dialysis Quality Initiative and the International Ascites Club Working Group in 2011. The aim of this study was to determine the prevalence of renal dysfunction according to the criteria in this proposal.

METHODS

The medical records of cirrhotic patients who were admitted to Konkuk University Hospital between 2006 and 2010 were reviewed retrospectively. The data obtained at first admission were collected. Acute kidney injury (AKI) and chronic kidney disease (CKD) were defined using the proposed diagnostic criteria of kidney dysfunction in cirrhosis.

RESULTS

Six hundred and forty-three patients were admitted, of whom 190 (29.5%), 273 (42.5%), and 180 (28.0%) were Child-Pugh class A, B, and C, respectively. Eighty-three patients (12.9%) were diagnosed with AKI, the most common cause for which was dehydration (30 patients). Three patients had hepatorenal syndrome type 1 and 26 patients had prerenal-type AKI caused by volume deficiency after variceal bleeding. In addition, 22 patients (3.4%) were diagnosed with CKD, 1 patient with hepatorenal syndrome type 2, and 3 patients (0.5%) with AKI on CKD.

CONCLUSIONS

Both AKI and CKD are common among hospitalized cirrhotic patients, and often occur simultaneously (16.8%). The most common type of renal dysfunction was AKI (12.9%). Diagnosis of type 2 hepatorenal syndrome remains difficult. A prospective cohort study is warranted to evaluate the clinical course in cirrhotic patients with renal dysfunction.

Evaluation of renal function in patients with cirrhosis: Where are we now?

In the clinical context of the patients with liver cirrhosis, accurate evaluation of the renal function is potentially crucial. Indeed, it can lead to early diagnosis of both acute kidney injury and chronic kidney disease and to reliable characterization of the renal status of the patient before performing a liver transplantation. Despite some limitations, the assay of serum creatinine (SCr) is universally used to estimate glomerular filtration rate (GFR) because of its wide availability, its simplicity and because it is inexpensive. Nevertheless, several reports show that the value of this assay to estimate GFR is strongly challenged in cirrhotic patients, especially in patients with liver failure and/or severely impaired renal function. This has led to seek new alternatives to estimate more reliably the GFR in these patients. Although the reference methods, based on the utilization of exogenous markers, allow measuring GFR and thereby constitute the “gold standard” to evaluate renal function, they are not feasible in routine clinical practice. Several studies have shown that a cystatin C (CysC) based formula perform better than the SCr-based estimates in cirrhotic patients and the estimation of GFR by these formulas could therefore lead to optimize the management of the patients. A new estimate based on CysC has been recently developed using a large number of patients and the first results regarding the evaluation of its performance are promising, making this new formula the best candidate for a reference estimate of the renal function in cirrhotic patients.

The model for end-stage liver disease score-based system predicts short term mortality better than the current Child-Turcotte-Pugh score-based allocation system during waiting for deceased liver transplantation

To adopt the model for end-stage liver disease (MELD) score-based system in Korea, the feasibility should be evaluated by analysis of Korean database. The aim of this study was to investigate the feasibility of the MELD score-based system compared with the current Child-Turcotte-Pugh (CTP) based-system and to suggest adequate cut-off to stratify waiting list mortality among Korean population. We included 788 adult patients listed in waiting list in Seoul National University Hospital from January 2008 to May 2011. The short-term survival until 6 months after registration was evaluated. Two hundred forty six (31.2%) patients underwent live donor liver transplantation and 353 (44.8%) patients were still waiting and 121 (15.4%) patients were dropped out due to death. Significant difference was observed when MELD score 24 and 31 were used as cut-off. Three-months survival of Status 2A was 70.2%. However, in Status 2A patients whose MELD score less than 24 (n=82), 86.6% of patients survived until 6 month. Furthermore, patients with high MELD score (≥31) among Status 2B group showed poorer survival rate (45.8%, 3-month) than Status 2A group. In conclusion, MELD score-based system can predict short term mortality better and select more number of high risk patients in Korean population.

Association between ratio of sodium to potassium in random urine samples and renal dysfunction and mortality in patients with decompensated cirrhosis

BACKGROUND & AIMS

Estimates of glomerular filtration rate (GFR) are used to assess renal function and are an independent prognostic factor for patients with decompensated cirrhosis, but are impractical for routine use. We investigated whether the ratio of sodium to potassium in randomly collected urine samples (UNa/K) is associated with mortality and renal dysfunction in patients with decompensated cirrhosis and ascites.

METHODS

We assessed data from 126 consecutive patients with decompensated cirrhosis and ascites (93 men; age, 56 ± 12 y; 55% with viral-related disease) admitted to the Hippokration General Hospital of Thessaloniki, Greece, from September 2010 through January 2012. At admission, clinical and laboratory variables were recorded, including GFR, measured with (51)Cr-EDTA. Urine samples were collected, and UNa/K was determined. We evaluated the association between UNa/K and patient mortality using the area under the receiver operating characteristic curve analysis.

RESULTS

Forty-one patients (32%; group 1) had a GFR less than 60 mL/min, and 85 patients (68%; group 2) had a GFR of 60 mL/min or greater. In the multivariable analysis, 3 variables were associated independently with the presence of severe renal dysfunction (GFR, <60 mL/min): age (odds ratio [OR], 0.93; P = .008), systolic blood pressure (OR, 1.05; P = .022), and UNa/K (OR, 1.5; P = .025). A UNa/K less than 1.0 had high sensitivity and a negative predictive value for the presence of GFR less than 60 mL/min (79% and 87%, respectively) and mortality (68% and 91%, respectively).

CONCLUSIONS

In patients with decompensated cirrhosis and ascites, a ratio of sodium to potassium of less than 1 in randomly collected urine samples was associated with renal dysfunction and short-term mortality. These findings require confirmation in additional studies.

Important predictor of mortality in patients with end-stage liver disease

Prognosis is an essential part of the baseline assessment of any disease. For predicting prognosis of end-stage liver disease, many prognostic models were proposed. Child-Pugh score has been the reference for assessing the prognosis of cirrhosis for about three decades in end-stage liver disease. Despite of several limitations, recent large systematic review showed that Child-Pugh score was still robust predictors and it's components (bilirubin, albumin and prothrombin time) were followed by Child-Pugh score. Recently, Model for end-stage liver disease (MELD) score emerged as a "modern" alternative to Child-Pugh score. The MELD score has been an important role to accurately predict the severity of liver disease and effectively assess the risk of mortality. Due to several weakness of MELD score, new modified MELD scores (MELD-Na, Delta MELD) have been developed and validated. This review summarizes the current knowledge about the prognostic factors in end-stage liver disease, focusing on the role of Child-Pugh and MELD score.

Current limits and future challenges in the management of renal dysfunction in patients with cirrhosis: report from the International Club of Ascites

Advanced cirrhosis is often complicated by a multi organ failure syndrome which involves many different organs besides the liver. The high morbidity and mortality secondary to this clinical setting is often related to renal dysfunction, either alone or, more frequently, in combination with other organ dysfunction. A clear definition of renal dysfunction, an accurate differential diagnostic process of its different phenotypes as well as of full understanding of its pathophysiological mechanisms are crucial to the development of strategies for the management of this complication. This article is based either on the more recent knowledge on renal dysfunction in advanced cirrhosis or current opinions among the members of the International Club of Ascites (ICA) on the management of this complication, obtained through a survey and discussed during the EASL-ICA Joint Meeting in Berlin in March 2011. It reviews critically our current knowledge and it outlines future perspectives, on the management of renal dysfunction in patients with cirrhosis.

Is an estimated glomerular filtration rate better than creatinine to be incorporated into the end-stage liver disease score?

AIM

To incorporate estimated glomerular filtration rate (eGFR) into the model for end-stage liver disease (MELD) score to evaluate the predictive value.

METHODS

From January 2004 to October 2008, the records of 4127 admitted cirrhotic patients were reviewed. Patients who survived and were followed up as outpatients were defined as survivors and their most recent available laboratory data were collected. Patients whose records indicated death at any time during the hospital stay were defined as non-survivors (in-hospital mortality). Patients with incomplete data or with cirrhosis due to a congenital abnormality such as primary biliary cirrhosis were excluded; thus, a total of 3857 patients were enrolled in the present study. The eGFR, which was calculated by using either the modification of diet in renal disease (MDRD) equation or the chronic kidney disease epidemiology collaboration (CKD-EPI) equation, was incorporated into the MELD score after adjustment with the original MELD equation by logistic regression analysis [bilirubin and international normalized ratio (INR) were set at 1.0 for values less than 1.0].

RESULTS

Patients defined as survivors were significantly younger, had a lower incidence of hepatoma, lower Child-Pugh and MELD scores, and better renal function. The underlying causes of cirrhosis were very different from those in Western countries. In Taiwan, most cirrhotic patients were associated with the hepatitis virus, especially hepatitis B. There were 16 parameters included in univariate logistic regression analysis to predict in-hospital mortality and those with significant predicting values were included in further multivariate analysis. Both 4-variable MDRD eGFR and 6-variable MDRD eGFR, rather than creatinine, were significant predictors of in-hospital mortality. Three new equations were constructed (MELD-MDRD-4, MELD-MDRD-6, MELD-CKD-EPI). As expected, original MELD score was a significant predictor of in-hospital mortality (odds ratio = 1.25, P < 0.001). MELD-MDRD-4 excluded serum creatinine, with the coefficients refit among the remaining 3 variables, i.e., total bilirubin, INR and 4-variable MDRD eGFR. This model represented an exacerbated outcome over MELD score, as suggested by a decrease in chi-square (2161.45 vs 2198.32) and an increase in -2 log (likelihood) (2810.77 vs 2773.90). MELD-MDRD-6 included 6-variable MDRD eGFR as one of the variables and showed an improvement over MELD score, as suggested by an increase in chi-square (2293.82 vs 2198.32) and a decrease in -2 log (likelihood) (2810.77 vs 2664.79). Finally, when serum creatinine was replaced by CKD-EPI eGFR, it showed a slight improvement compared to the original MELD score (chi-square: 2199.16, -2 log (likelihood): 2773.07). In the receiver-operating characteristic curve, the MELD-MDRD-6 score showed a marginal improvement in area under the curve (0.909 vs 0.902), sensitivity (0.854 vs 0.819) and specificity (0.818 vs 0.839) compared to the original MELD equation. In patients with a different eGFR, the MELD-MDRD-6 equation showed a better predictive value in patients with eGFR ≥ 90, 60-89, 30-59 and 15-29.

CONCLUSION

Incorporating eGFR obtained by the 6-variable MDRD equation into the MELD score showed an equal predictive performance in in-hospital mortality compared to a creatinine-based MELD score.

Predicting survival after living and deceased donor liver transplantation in adult patients with acute liver failure

BACKGROUND

Post-transplant outcomes for acute liver failure (ALF) are unsatisfactory, and there are debates about the most suitable type of graft. Given the critical shortage of donor organs, accurate assessment of post-transplant outcome in ALF patients is crucial to avoid a futile liver transplantation (LT).

METHODS

A database of 160 consecutive adult ALF patients who underwent primary LT between 2000 and 2009 in a tertiary LT center was analyzed.

RESULTS

The most common causes of ALF were hepatitis B virus infection (30%) and herbal/folk medicine use (30%). Thirty-six (22.5%) and 124 (77.5%) patients underwent deceased-donor LT (DDLT) and adult-to-adult living-donor LT (LDLT), respectively. During a median follow-up period of 38 (range 1-132) months, the DDLT and LDLT groups showed similar patient (P = 0.99) and graft (P = 0.97) survival rates. The overall 1- and 3-year patient survival rates were 78.8 and 74.6%, respectively. Five predictors of patient survival were identified by bootstrapping and multivariate analysis: vasopressor requirement, estimated glomerular filtration rate, serum sodium concentration, recipient age, and donor age, at the time of transplant. By summing scores weighted in each of these predictor categories, we designed a prognostic scoring system (scores from -2 to 20) that estimated 1-year post-transplant mortality from 0 to 100% (c statistic 0.79).

CONCLUSIONS

Long-term outcomes after LDLT and DDLT were comparable in adult patients with ALF. A simple prognostic scoring system that includes 5 predictive variables at the time of LT may help estimate post-transplant survival in ALF patients, regardless of the type of transplant.

Significance of hypo- and hypernatremia in chronic kidney disease

Both hypo- and hypernatremia are common conditions, especially in hospitalized patients and in patients with various comorbid conditions such as congestive heart failure or liver cirrhosis. Abnormal serum sodium levels have been associated with increased mortality in numerous observational studies. Patients with chronic kidney disease (CKD) represent a group with a high prevalence of comorbid conditions that could predispose to dysnatremias. In addition, the failing kidney is also characterized by a gradual development of hyposthenuria, and even isosthenuria, which results in further predisposition to the development of hypo- and hypernatremia in those with advancing stages of CKD. To date, there has been a paucity of population-wide assessments of the incidence and prevalence of dysnatremias, their clinical characteristics and the outcomes associated with them in patients with various stages of CKD. We review the physiology and pathophysiology of water homeostasis with special emphasis on changes occurring in CKD, the outcomes associated with abnormal serum sodium in patients with normal kidney function and the results of recent studies in patients with various stages of CKD, which indicate a substantial incidence and prevalence and significant adverse outcomes associated with dysnatremias in this patient population.

Sodium handling is associated with liver function impairment and renin-aldosterone axis activity in patients with preascitic cirrhosis without hyponatremia

BACKGROUND

In cirrhotic patients awaiting liver transplantation, serum sodium concentration is related to prognosis. However, abnormalities in sodium homeostasis are evident even in the early preascitic stage of cirrhosis. We aimed to investigate whether parameters of renal sodium handling (serum sodium, urinary sodium and fractional exertion of sodium (FeNa%) correlate with markers of liver function and renin-aldosterone axis activity in patients with preascitic cirrhosis without hyponatremia.

METHODS

Patients with preascitic cirrhosis without hyponatremia underwent routine blood and urine laboratory tests, including markers of liver function impairment and sodium homeostasis.

RESULTS

Thirty eight cirrhotic patients (22 men) with mean age of 57.3±12.2 (SD) years were included. Twenty six and twelve patients were at Child-Pugh stage A and B cirrhosis respectively. Eighteen patients had a Model for End-stage Liver Disease (MELD) score of ≤9 and twenty had MELD >9. Serum sodium was found to differ significantly between Child-Pugh stage A and B cirrhotics (mean 142.8±2.0 mmol/L vs. 140.5±3.3 mmol/L, p<0.05). Serum sodium was also found to differ significantly between patients with MELD score ≤9 and >9 (mean 143.3±2.0 mmol/L vs. 140.9±2.8 mmol/L, respectively, p<0.01). Serum sodium correlated negatively with the international normalized ratio (INR) (r=-0.51, p<0.01), aldosterone (r=-0.40, p<0.05), Child-Pugh and MELD scores (r=-0.34, p<0.05 and r=-0.45, p<0.05 respectively). FeNa% correlated negatively with renin and aldosterone (r=-0.56, p<0.001 and r=-0.50, p<0.01 respectively).

CONCLUSION

Serum sodium concentration is a good surrogate marker of liver function impairment not only in late-stage liver cirrhosis before transplantation but also in the early preascitic stage.

Hot-topic debate on kidney function: renal-sparing approaches are beneficial

1. Renal function is frequently compromised in candidates for transplantation with advanced cirrhosis. These patients frequently have chronic and irreversible kidney changes at the time of transplantation. 2. The accumulated incidence of chronic renal failure is high in liver transplant recipients. Chronic renal failure has a deleterious impact on the outcome. 3. Calcineurin inhibitor (CNI)-based immunosuppression is highly effective at preventing rejection. However, CNI nephrotoxicity has a central role in the occurrence of chronic renal failure. 4. Renal function impairment frequently occurs within the first year after transplantation. Once renal function is significantly impaired [glomerular filtration rate (GFR) < 60 mL/minute/1.73 m(2) ], any intervention is unlikely to result in a return to normal renal function. Early interventions are needed to prevent chronic and irreversible kidney injury. 5. De novo CNI minimization has been proven to be effective at reducing the rate of impaired renal function after transplantation. The reduction in the CNI doses should be offset by the addition of mycophenolate mofetil or enteric-coated mycophenolate sodium. 6. Delayed CNI minimization in patients with established renal insufficiency may result in a significant improvement in the GFR, even though the increase in the GFR after minimization is generally modest. 7. Mammalian target of rapamycin (mTOR) inhibitors are considered nonnephrotoxic immunosuppressive agents. They may be an option for improving renal function in liver transplant recipients. However, not all patients with renal dysfunction benefit from a switch to mTOR inhibitors. In addition, the benefits in terms of renal function should be balanced against specific side effects. 8. New immunosuppressive agents without intrinsic nephrotoxicity are currently under development for solid organ transplantation. These agents could help to reduce the burden of impaired renal function in transplantation in the near future.

Model for end-stage liver disease: end of the first decade

The Model for End-stage Liver Disease (MELD) score is the basis for allocation of liver allografts for transplantation in the United States. The MELD score, as an objective scale of disease severity, is also used in the management of patients with chronic liver disease in the nontransplant setting. Several models have been proposed to improve the MELD score. The authors believe that the MELD score is, by design, continually evolving and lends itself to continued refinement and improvement to serve as a metric to optimize organ allocation in the future.

Acute-on-chronic liver failure: the kidneys

PURPOSE OF REVIEW

Acute-on-chronic liver failure (ACLF) is defined as an abrupt deterioration of liver function in patients with established liver disease. Kidney function is almost universally altered in patients with ACLF due to underlying circulatory abnormalities. We review current advances during the past year in the diagnosis and management of renal failure in ACLF.

RECENT FINDINGS

The adequate measurement of renal function by means of clearance methods remains the gold standard for estimation of the glomerular filtration rate in patients with cirrhosis. The new definition of acute kidney injury needs to be specifically studied in patients with cirrhosis. Alternative kidney biomarkers of renal function in cirrhosis are promising and need further investigation. The most common cause of renal failure in cirrhosis is that associated with infections followed by hypovolemia-induced renal failure, intrinsic renal diseases, hepatorenal syndrome, and drug-induced renal failure. Adrenal insufficiency commonly occurs in patients with cirrhosis and hemodynamic instability. The proper diagnosis relies on corticotropin stimulation testing and the role of hydrocortisone therapy in these patients merits further investigation. Hyponatremia in cirrhosis is a major risk factor for the development of hepatic encephalopathy and is associated with a poor outcome in patients with ACLF and also after deceased donor and living-related liver transplantation. Vasoconstrictor drugs, particularly terlipressin, are effective for the management of hepatorenal syndrome. Predictive factors of response to terlipressin include serum bilirubin levels and the presence of an early increase in mean arterial pressure.

SUMMARY

The ongoing advances in the diagnosis and management of patients with ACLF and renal failure will improve the diagnosis, therapy and outcome of these patients.

Pitfalls in assessing renal function in patients with cirrhosis--potential inequity for access to treatment of hepatorenal failure and liver transplantation

Serum creatinine is universally used to assess renal function in clinical practice. Creatinine and changes in serum creatinine are used to define acute kidney injury and hepatorenal syndrome (HRS) in patients with progressive liver disease. In addition, creatinine is a key variable in the calculation used to determine priority for liver transplantation in many countries. As there is no universal standardized creatinine assay, there is variation in creatinine determinations between laboratory assays, compounded by assay interference due to chromogens, including bilirubin. This leads to patients with the same actual renal function potentially being offered different treatment options, in terms of access to therapy for HRS and priority waiting time for liver transplantation. Alternative methods for assessing renal function either also tend to overestimate renal function or are too time consuming and expensive to provide practical alternatives for standard clinical practice. Standardization of creatinine assays with readily available reference standards would help minimize interlaboratory variation; of the current creatinine assays, enzymatic creatinine appears more accurate, but even this is inaccurate at high bilirubin concentrations. Further work is required to determine whether interpatient variation can be reduced by correcting creatinine and cystatin measurements for muscle mass.

Gender, renal function, and outcomes on the liver transplant waiting list: assessment of revised MELD including estimated glomerular filtration rate

BACKGROUND & AIMS

The Model for End-Stage Liver Disease (MELD) allocation system for liver transplantation (LT) may present a disadvantage for women by including serum creatinine, which is typically lower in females. Our objectives were to investigate gender disparities in outcomes among LT candidates and to assess a revised MELD, including estimated glomerular filtration rate (eGFR), for predicting waiting list mortality.

METHODS

Adults registered for LT between 2002 and 2007 were identified using the UNOS database. We compared components of MELD, MDRD-derived eGFR, and the 3-month probability of LT and death between genders. Discrimination of MELD, MELDNa, and revised models including eGFR for mortality were compared using c-statistics.

RESULTS

A total of 40,393 patients (36% female) met the inclusion criteria; 9% died and 24% underwent LT within 3 months of listing. Compared with men, women had lower median serum creatinine (0.9 vs. 1.0 mg/dl), eGFR (72 vs. 83 ml/min/1.73 m(2)), and mean MELD (16.5 vs. 17.2; all p <0.0005), but within most MELD strata, had higher bilirubin and INR. After adjusting for relevant covariates including creatinine and body weight, women were less likely than men to receive a LT (hazard ratio [HR] 0.85; 95% CI 0.79-0.87) and had greater 3-month mortality (HR 1.13; 95% CI 1.05-1.21). Revision of MELD and MELDNa to include eGFR did not improve discrimination for 3-month mortality (c-statistics: MELD 0.896, MELD-eGFR 0.894, MELDNa 0.911, MELDNa-eGFR 0.905).

CONCLUSIONS

Women are disadvantaged under MELD potentially due to its inclusion of creatinine. However, since including eGFR in MELD does not improve mortality prediction, alternative refinements are necessary.