Chronic Kidney Disease in Liver Transplant Candidates: A Rising Burden Impacting Post-Liver Transplant Outcomes

A new prediction model for acute kidney injury following liver transplantation using grafts from donors after cardiac death

Acute kidney injury (AKI) is a major complication following liver transplantation (LT), which utilizes grafts from donors after cardiac death (DCD). We developed a machine-learning-based model to predict AKI, using data from 894 LT recipients (January 2015-March 2021), split into training and testing sets. Five machine learning algorithms were employed to construct the prediction models using 17 clinical variables. The performance of the models was assessed by the area under the receiver operating characteristic curve (AUC), accuracy, F1-score, sensitivity and specificity. The best-performing model was further validated in an independent cohort of 195 LT recipients who received DCD grafts between April 2021 and December 2021. The Shapley additive explanations method was utilized to elucidate the predictions and identify the most crucial features. The gradient boosting machine (GBM) model demonstrated the highest AUC (0.76, 95% CI: 0.70-0.82), F1-score (0.73, 95% CI: 0.66-0.79) and sensitivity (0.74, 95% CI: 0.66-0.80) in the testing set and a comparable AUC (0.75, 95% CI: 0.67-0.81) in the validation set. The GBM model identified high preoperative indirect bilirubin, low intraoperative urine output, prolonged anesthesia duration, low preoperative platelet count and graft steatosis graded NASH Clinical Research Network 1 and above as the top five important features for predicting AKI following LT using DCD grafts. The GBM model is a reliable and interpretable tool for predicting AKI in recipients of LT using DCD grafts. This model can assist clinicians in identifying patients at high risk and providing timely interventions to prevent or mitigate AKI.

Clinical Characteristics Associated With Posttransplant Survival Among Adults 70 Years Old or Older Undergoing Liver Transplantation

GOALS

We sought to identify pre-liver transplantation (LT) characteristics among older adults associated with post-LT survival.

BACKGROUND

The proportion of older patients undergoing deceased-donor liver transplantation (DDLT) has increased over time.

STUDY

We analyzed adult DDLT recipients in the United Network for Organ Sharing registry from 2016 through 2020, excluding patients listed as status 1 or with a model of end-stage liver disease exceptions for hepatocellular carcinoma. Kaplan-Meier methods were used to estimate post-LT survival probabilities among older recipients (age ≥70 y). Associations between clinical covariates and post-LT mortality were assessed using Cox regressions.

RESULTS

Of 22,862 DDLT recipients, 897 (4%) were 70 years old or older. Compared with younger recipients, older recipients had worse overall survival ( P < 0.01) (1 y: 88% vs 92%, 3 y: 77% vs 86%, and 5 y: 67% vs 78%). Among older adults, in univariate Cox regressions, dialysis [hazards ratio (HR): 1.96, 95% CI: 1.38-2.77] and poor functional status [defined as Karnofsky Performance Score (KPS) <40] (HR: 1.82, 95% CI: 1.31-2.53) were each associated with mortality, remaining significant on multivariable Cox regressions. The effect of dialysis and KPS <40 at LT on post-LT survival (HR: 2.67, 95% CI: 1.77-4.01) was worse than the effects of either KPS <40 (HR: 1.52, 95% CI: 1.03-2.23) or dialysis alone (HR: 1.44, 95% CI: 0.62-3.36). Older recipients with KPS >40 without dialysis had comparable survival rates compared with younger recipients ( P = 0.30).

CONCLUSIONS

While older DDLT recipients had worse overall post-LT survival compared with younger recipients, favorable survival rates were observed among older adults who did not require dialysis and had poor functional status. Poor functional status and dialysis at LT may be useful to stratify older adults at higher risk for poor post-LT outcomes.

Everolimus Mitigates the Risk of Hepatocellular Carcinoma Recurrence after Liver Transplantation

To obtain long-term data on the use of everolimus in patients who underwent liver transplantation for hepatocellular carcinoma, we conducted a retrospective, single-center analysis of adult recipients transplanted between 2013 and 2021. Patients on everolimus-incorporating immunosuppression were matched with those on tacrolimus using an inverse probability of treatment weighting methodology. Two propensity-matched groups of patients were thus compared: 233 (45.6%) receiving everolimus versus 278 (54.4%) on tacrolimus. At a median (interquartile range) follow-up of 4.4 (3.8) years after transplantation, everolimus patients showed a reduced risk of recurrence versus tacrolimus (7.7% versus 16.9%; RR = 0.45; p = 0.002). At multivariable analysis, microvascular infiltration (HR = 1.22; p < 0.04) and a higher tumor grading (HR = 1.27; p < 0.04) were associated with higher recurrence rate while being within Milan criteria at transplant (HR = 0.56; p < 0.001), a successful pre-transplant downstaging (HR = 0.63; p = 0.01) and use of everolimus (HR = 0.46; p < 0.001) had a positive impact on the risk of post-transplant recurrence. EVR patients with earlier drug introduction (≤30 days; p < 0.001), longer treatment duration (p < 0.001), and higher drug exposure (≥5.9 ng/mL; p < 0.001) showed lower recurrence rates versus TAC. Based on our experience, everolimus provides a reduction in the relative risk of hepatocellular carcinoma recurrence, especially for advanced-stage patients and those with earlier drug administration, higher drug exposure, and longer time on treatment. These data advocate for early everolimus introduction after liver transplantation to reduce the attrition rate consequent to chronic immunosuppression.

Fragility spinal fractures among cirrhotic liver transplant candidates in Croatia

INTRODUCTION

Existing data on fragility spinal fractures prevalence in liver transplant candidates are scarce and inconsistent. This may be due to other comorbidities, besides hepatic osteodystrophy (HO), that contribute to bone loss and fragility fracture prevalence in chronic liver disease (CLD).

OBJECTIVES

The aim of this study was to investigate the prevalence of spinal thoracic and lumbar fragility fractures among cirrhotic, non-chronic kidney disease (CKD), non-diabetic liver transplant candidates and to explore their relationship with clinical characteristics, laboratory markers and dual-energy x-ray absorptiometry (DXA) results.

MATERIAL AND METHODS

This cross-sectional observational study was conducted at Merkur University Hospital, Croatia, between February 2019 and May 2023. Adult patients with liver cirrhosis referred for liver transplantation were included. Patients with acute infection, CKD, diabetes mellitus, malignancies, inflammatory bone diseases and those on corticosteroid or antiresorptive therapy were excluded. Clinical, laboratory and radiological assessment was carried out and patients were accordingly allocated into non-fractured and fractured group for the purpose of statistical analysis.

RESULTS

A total of 90 patients were included in the study. There was 123 fractures, 87 (70.7 %) in the thoracic and 36 (29.3 %) in the lumbar region. Eighty-nine (72.4 %) fractures were grade 1, 31 (25.2 %) were grade 2 and 3 (2.4 %) were grade 3. Patients in the fractured group were significantly older (p < 0.001). No significant differences between fractured and non-fractured group according to laboratory and DXA parameters were noted. Subgroup with lumbar fractures had significantly lower bone mineral density values at L1-L4 region. Statistically significant negative correlation between bone specific alkaline phosphatase (BALP) and hip total BMD (rho = -0.414, p < 0.001) and spine total BMD (rho = -0.258, p = 0.014) values was found.

CONCLUSION

Present study confirmed detrimental impact of CLD and HO on bone strength. DXA measurement correlated with the presence of lumbar fragility fractures. A combination of standard X-ray imaging and DXA is needed for adequate bone evaluation in pretransplant period and BALP could be useful for detecting HO in CLD. Searching for other risk factors and implementing bone turnover markers and additional imaging techniques for bone loss evaluation in liver transplant candidates is needed.

Angiotensin II type 1 receptor antibodies and native kidney function in pediatric liver and intestinal transplant recipients

BACKGROUND

Angiotensin II type-1 receptor antibody (AT1R-Ab) has been associated with vascular injury and kidney dysfunction in pediatric kidney transplant recipients. The role of AT1R-Ab in the development of chronic kidney disease in pediatric liver and intestinal transplant recipients has not been explored.

METHODS

Twenty-five pediatric intestinal transplant recipients and 79 pediatric liver transplant recipients had AT1R-Ab levels measured at varying time points in the post-transplant period. Estimated glomerular filtration rate (eGFR) was determined using creatinine based CKiD U25 equation and measured at time of AT1R-Ab measurement, at 1 year post-AT1R-Ab measurement, at 5 years post-AT1R-Ab measurement, and at the most recent routine clinic visit. The prevalence of hypertension and antihypertensive medication use were also evaluated.

RESULTS

Younger age at time of AT1R-Ab measurement was associated with AT1R-Ab positivity in liver transplant recipients. There was no association between AT1R-Ab status and change in eGFR, prevalence of hypertension, or use of antihypertensive medications at the described time points.

CONCLUSIONS

AT1R-Ab positivity was not associated with a decline in eGFR or hypertension in pediatric liver and intestinal transplant recipients. Further studies are needed using other markers of kidney function, such as cystatin C, to validate this finding. A higher resolution version of the Graphical abstract is available as Supplementary information.

Protocolized screening and detection of occult alcohol use before and after liver transplant: Lessons learned from a quality improvement initiative

INTRODUCTION

Detection of alcohol (ETOH) use with biomarkers provides an opportunity to intervene and treat patients with alcohol use disorder before and after liver transplant (LT). We describe our center's experience using urine ethyl glucuronide (EtG) and serum phosphatidylethanol (PEth) in alcohol screening protocols.

METHODS

Single-center, retrospective review of patients presenting for LT evaluation, patients waitlisted for LT for alcohol-associated liver disease (ALD), and patients who received a LT for ALD over a 12-month period, from October 1, 2019 through September 30, 2020. Patients were followed from waitlisting to LT, or for up to 12 months post-LT. We monitored protocol adherence to screening for ETOH use- defined as completion of all possible tests over the follow-up period- at the initial LT visit, while on the LT waitlist and after LT.

RESULTS

During the study period, 227 patients were evaluated for LT (median age 57 years, 58% male, 78% white, 54.2% ALD). Thirty-one patients with ALD were placed on the waitlist, and 38 patients underwent LT for ALD during this time period. Protocolized adherence to screening for alcohol use was higher for PEth for all LT evaluation patients (191 [84.1%] vs. 146 [67%] eligible patients, p < .001), in patients with ALD waitlisted for LT (22 [71%] vs. 14 (48%] eligible patients, p = .04) and after LT for ALD, 20 (33 [86.8%] vs. 20 [52.6%] eligible patients, p < .01). Few patients with a positive test in any group completed chemical dependency treatment.

CONCLUSIONS

When screening for ETOH use in pre- and post-LT patients, protocol adherence is higher using PEth compared to EtG. While protocolized biomarker screening can detect recurrent ETOH use in this population, engagement of patients into chemical dependency treatment remains challenging.

The Impact of Renal Function on Hepatic Encephalopathy Following TIPS Placement for Refractory Ascites

BACKGROUND

The impact of renal function on hepatic encephalopathy (HE) following transjugular intrahepatic portosystemic shunt (TIPS) placement for refractory ascites is poorly understood. We investigated the role of renal function on HE following TIPS placement.

METHODS

A retrospective study was performed for patients undergoing TIPS for refractory ascites from 2007-2019. Patients were stratified by GFR at time of TIPS placement and by whether they were on hemodialysis (HD). Chronic kidney disease (CKD) stage 3 or higher was defined as pre-TIPS GFR < 60 for at least 3 months. Logistic regression analyses were used to identify the role of GFR and CKD at time of TIPS placement on HE within 60 days post TIPS placement.

RESULTS

Among 201 TIPS patients for refractory ascites (61% male; mean age 59.1), 78 (39%) patients were in CKD, and 16 (21%) were on HD. Mean GFR at time of TIPS placement was 62.7 ± 28.2 for all non-HD patients (n = 185). Compared with the GFR ≥ 90 group, GFR < 30 or HD (OR, 3.56; 95%CI, 1.19-10.7; p = 0.023) and CKD (OR, 2.52; 95%CI, 1.40-4.53; p = 0.002) at time of TIPS placement were significant predictors of post-TIPS placement HE within 60 days. GFRs between 30-60 and 60-90 were not significant predictors.

CONCLUSIONS

In TIPS patients for recurrent ascites, patients with acutely impaired renal function or chronic renal dysfunction were at an increased risk for HE after TIPS.

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.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Essentials of Liver Transplantation in the Setting of Acute Kidney Injury and Chronic Kidney Disease

Kidney dysfunction is common among liver transplant candidates with decompensated cirrhosis and has a major impact on pre- and post-liver transplant survival. Updated definitions of acute kidney injury and criteria for the diagnosis of hepatorenal syndrome allow for early recognition and intervention, including early initiation of vasoconstrictor therapy for hepatorenal syndrome. The rise of the metabolic syndrome and nonalcoholic fatty liver disease as a cause of cirrhosis has coincided with an increase in intrinsic chronic kidney disease recognized in transplant candidates and recipients. Ultimately, the ability to accurately assess kidney function and associated risk is essential to decision-making in the context of transplantation, including selection of candidates for simultaneous liver and kidney transplantation.

Longer time to recovery from acute kidney injury is associated with major adverse kidney events in patients with cirrhosis

BACKGROUND

In patients with cirrhosis and acute kidney injury (AKI), longer time to AKI-recovery may increase the risk of subsequent major-adverse-kidney-events (MAKE).

AIMS

To examine the association between timing of AKI-recovery and risk of MAKE in patients with cirrhosis.

METHODS

Hospitalised patients with cirrhosis and AKI (n = 5937) in a nationwide database were assessed for time to AKI-recovery and followed for 180-days. Timing of AKI-recovery (return of serum creatinine <0.3 mg/dL of baseline) from AKI-onset was grouped by Acute-Disease-Quality-Initiative Renal Recovery consensus: 0-2, 3-7, and >7-days. Primary outcome was MAKE at 90-180-days. MAKE is an accepted clinical endpoint in AKI and defined as the composite outcome of ≥25% decline in estimated-glomerular-filtration-rate (eGFR) compared with baseline with the development of de-novo chronic-kidney-disease (CKD) stage ≥3 or CKD progression (≥50% reduction in eGFR compared with baseline) or new haemodialysis or death. Landmark competing-risk multivariable analysis was performed to determine the independent association between timing of AKI-recovery and risk of MAKE.

RESULTS

4655 (75%) achieved AKI-recovery: 0-2 (60%), 3-7 (31%), and >7-days (9%). Cumulative-incidence of MAKE was 15%, 20%, and 29% for 0-2, 3-7, >7-days recovery groups, respectively. On adjusted multivariable competing-risk analysis, compared to 0-2-days, recovery at 3-7 and >7-days was independently associated with an increased risk for MAKE: sHR 1.45 (95% CI 1.01-2.09, p = 0.042), sHR 2.33 (95% CI 1.40-3.90, p = 0.001), respectively.

CONCLUSION

Longer time to recovery is associated with an increased risk of MAKE in patients with cirrhosis and AKI. Further research should examine interventions to shorten AKI-recovery time and its impact on subsequent outcomes.

The Conundrum of Patients With Compensated Cirrhosis Requiring Kidney Transplantation; Kidney Alone or Simultaneous Liver Kidney Transplantation

BACKGROUND

Patients with compensated cirrhosis and chronic kidney disease are increasing along with demand for simultaneous liver kidney transplant (SLKT) and shortages of organs for transplantation. Although these well-compensated patients may not need a liver organ, the alternative of kidney transplant alone (KTA) poses the risk of liver decompensation. Therefore, we aim to characterize outcomes among patients with compensated cirrhosis and chronic kidney disease listed for SLKT or receiving KTA to inform clinical decisions.

METHODS

The 2-part retrospective study included a national cohort of patients listed for SLKT in United Network for Organ Sharing from January 2003 to June 2019 with Child A cirrhosis, with model for end-stage liver disease <25, and receiving dialysis; and a cohort of patients who underwent KTA from 2004 to 2019 with Child A cirrhosis identified through a 4-center chart review. Waitlist outcomes (SLKT, death, and clinical improvement) and post-KTA liver decompensation and survival were evaluated in the cohorts, respectively.

RESULTS

In the national SLKT cohort (N = 705, median age 56 y, 68.8% male), 5-y cumulative incidence of SLKT was 43.1%, death 32.1%, and clinical improvement 9.1%. Among SLKT recipients, 36.3% remained Child A without ascites or encephalopathy at transplant. In the local KTA cohort (N = 34, median age 54 y, 79.4% male), none had ascites or hepatic encephalopathy before KTA, but 15 had clinical portal hypertension. Five-y post-KTA incidence of liver decompensation was 36.8%, and survival was 89.2%.

CONCLUSIONS

SLKT may not be necessary for some patients with compensated cirrhosis needing kidney transplant. KTA is safe for selected patients with intact liver biochemical function, even with portal hypertension but without hepatic encephalopathy or ascites.

Acute Kidney Injury in Patients with Liver Disease

AKI is commonly encountered in patients with decompensated cirrhosis, and it is associated with unfavorable outcomes. Among factors specific to cirrhosis, hepatorenal syndrome type 1, also referred to as hepatorenal syndrome-AKI, is the most salient and unique etiology. Patients with cirrhosis are vulnerable to traditional causes of AKI, such as prerenal azotemia, acute tubular injury, and acute interstitial nephritis. In addition, other less common etiologies of AKI specifically related to chronic liver disease should be considered, including abdominal compartment syndrome, cardiorenal processes linked to cirrhotic cardiomyopathy and portopulmonary hypertension, and cholemic nephropathy. Furthermore, certain types of GN can cause AKI in cirrhosis, such as IgA nephropathy or viral hepatitis related. Therefore, a comprehensive diagnostic approach is needed to evaluate patients with cirrhosis presenting with AKI. Management should be tailored to the specific underlying etiology. Albumin-based volume resuscitation is recommended in prerenal AKI. Acute tubular injury and acute interstitial nephritis are managed with supportive care, withdrawal of the offending agent, and, potentially, corticosteroids in acute interstitial nephritis. Short of liver transplantation, vasoconstrictor therapy is the primary treatment for hepatorenal syndrome type 1. Timing of initiation of vasoconstrictors, the rise in mean arterial pressure, and the degree of cholestasis are among the factors that determine vasoconstrictor responsiveness. Large-volume paracentesis and diuretics are indicated to relieve intra-abdominal hypertension and renal vein congestion. Direct-acting antivirals with or without immunosuppression are used to treat hepatitis B/C-associated GN. In summary, AKI in cirrhosis requires careful consideration of multiple potentially pathogenic factors and the implementation of targeted therapeutic interventions.

Metabolic mechanisms for and treatment of NAFLD or NASH occurring after liver transplantation

The rising tide of non-alcoholic fatty liver disease (NAFLD) associated with the obesity epidemic is a major health concern worldwide. NAFLD - specifically its more advanced form, non-alcoholic steatohepatitis (NASH)-related cirrhosis - is now the fastest growing indication for liver transplantation in the USA and Europe. Although the short-term and mid-term overall survival rates of patients who receive a liver transplant for NASH-related cirrhosis are essentially similar to those of patients who receive a transplant for other liver indications, recipients with NASH-related cirrhosis have an increased risk of waiting-list mortality and of developing recurrent liver disease and cardiometabolic complications in the longer term after liver transplantation. This Review provides a brief overview of the epidemiology of NAFLD and NASH and the occurrence of NAFLD or NASH in patients after liver transplantation for NASH and other liver indications. It also discusses the putative metabolic mechanisms underlying the emergence of NAFLD or NASH after liver transplantation as well as optimal therapeutic approaches for recipients of liver transplants, including the management of cardiometabolic comorbidities, tailored immunosuppression, lifestyle changes and pharmacotherapy for NAFLD.

Variability in serum creatinine is associated with waitlist and post-liver transplant mortality in patients with cirrhosis

BACKGROUND AND AIMS

Kidney function in patients with cirrhosis is dynamic. After controlling for the presence of chronic kidney disease (CKD) and acute kidney injury (AKI), we investigated the impact of variation in clinical function on pre-liver transplantation (LT) and post-LT outcomes.

APPROACH AND RESULTS

We included adults listed for LT from 2011 through 2018. We excluded those with any exceptions, those on hemodialysis at listing, and those with fewer than three clinical updates in the United Network for Organ Sharing database. Our primary exposure was the serum creatinine coefficient of variation (sCr CoV). Logistic regression determined the associations between our exposures and higher sCr CoV. Competing risk regression determined the associations between our exposures and waitlist mortality, accounting for LT as a competing risk. Cox regression determined the associations between our exposures and either listing for kidney transplant or death. We divided our cohort into tertiles of sCr CoV: low variability, 8.8% (interquartile range [IQR], 6.6%-10.8%); intermediate variability, 17.4% (IQR, 14.8%-20.4%); high variability, 36.8% (IQR, 29.5%-48.8%). We demonstrate that women, those with CKD, and those with advanced liver disease were more likely to have a greater sCr CoV. Compared to those with low variability, those with high variability had significantly higher waitlist mortality (34.7% vs. 19.6% vs. 11.7%, p < 0.001). We highlight that the sCr CoV was associated with higher waitlist and post-LT mortality-an association independent of baseline sCr, the degree of underlying liver disease, the presence of AKI, or the presence of CKD.

CONCLUSION

This study informs the long-term impact of the variation in kidney function we all see in clinical practice. These data highlight that all fluctuations in sCr are associated with worse pre-LT and post-LT outcomes.

Improving the Model for End-Stage Liver Disease with sodium by incorporating kidney dysfunction types

BACKGROUND AND AIMS

We investigated the impact of the inclusion of kidney dysfunction type on the discrimination and calibration of the Model for End-Stage Liver Disease with sodium (MELD-Na-KT) score.

APPROACH AND RESULTS

We included all adults listed for ≥90 days without exception points from January 1, 2008, through December 31, 2018. We defined kidney dysfunction types as follows: acute kidney disease (AKD; an increase of ≥0.3 mg/dL or ≥50% in serum creatinine in the last 7 days or fewer than 72 days of hemodialysis), chronic kidney disease (CKD; an estimated glomerular filtration rate <60 ml/min/1.73 m2  for 90 days or ≥72 days of hemodialysis), AKD on CKD (met both definitions), or none (met neither definition). We then developed and validated a multivariable survival model with follow-up beginning at the first assessment after 90 days from waitlist registration and ending at the time of death, waitlist removal, or 90 days from enrollment in this study. The predictor variables were MELD-Na and the derived MELD-Na-KT model. In the derivation cohort, kidney dysfunction type was significantly associated with waitlist mortality after controlling for MELD-Na. There was a significant linear interaction between kidney dysfunction type and MELD-Na score. In the validation cohort, we saw an improvement in the discrimination of the model with an increase in the c-index from 0.76 with MELD-Na to 0.78 with MELD-Na-KT (p = 0.002) and a net reclassification index of 10.8% (95% CI, 1.9%-11.4%). The newly derived MELD-Na-KT model had lower Brier scores (MELD-Na-KT 0.042 vs. MELD-Na 0.053).

CONCLUSIONS

This study demonstrates the feasibility and the potential for objectively defined kidney dysfunction types to enhance the prognostication of waitlist mortality provided by the MELD-Na score.

Acute kidney disease is common and associated with poor outcomes in patients with cirrhosis and acute kidney injury

BACKGROUND & AIMS

Acute kidney disease (AKD) is the persistence of acute kidney injury (AKI) for up to 3 months, which is proposed to be the time-window where critical interventions can be initiated to alter downstream outcomes of AKI. In cirrhosis, AKD and its impact on outcomes have been scantly investigated. We aimed to define the incidence and outcomes associated with AKD in a nationwide US cohort of hospitalized patients with cirrhosis and AKI.

METHODS

Hospitalized patients with cirrhosis and AKI in the Cerner-Health-Facts database from 1/2009-09/2017 (n = 6,250) were assessed for AKD and were followed-up for 180 days. AKI and AKD were defined based on KDIGO and ADQI AKD and renal recovery consensus criteria, respectively. The primary outcome measure was mortality, and the secondary outcome measure was de novo chronic kidney disease (CKD). Competing-risk multivariable models were used to determine the independent association of AKD with primary and secondary outcomes.

RESULTS

AKD developed in 32% of our cohort. On multivariable competing-risk analysis adjusting for significant confounders, patients with AKD had higher risk of mortality at 90 (subdistribution hazard ratio [sHR] 1.37; 95% CI 1.14-1.66; p = 0.001) and 180 (sHR 1.37; 95% CI 1.14-1.64; p = 0.001) days. The incidence of de novo CKD was 37.5%: patients with AKD had higher rates of de novo CKD (64.0%) compared to patients without AKD (30.7%; p <0.001). After adjusting for confounders, AKD was independently associated with de novo CKD (sHR 2.52; 95% CI 2.01-3.15; p <0.001) on multivariable competing-risk analysis.

CONCLUSIONS

AKD develops in 1 in 3 hospitalized patients with cirrhosis and AKI and it is associated with worse survival and de novo CKD. Interventions that target AKD may improve outcomes of patients with cirrhosis and AKI.

LAY SUMMARY

In a nationwide US cohort of hospitalized patients with cirrhosis and acute kidney injury, acute kidney disease developed in 1 in 3 patients and was associated with worse survival and chronic kidney disease. Interventions that target acute kidney disease may improve outcomes of patients with cirrhosis and acute kidney injury.

Association Between Kidney Dysfunction Types and Mortality Among Hospitalized Patients with Cirrhosis

BACKGROUND AND AIMS

Kidney dysfunction is associated with increased mortality among patients with cirrhosis. We investigated whether kidney dysfunction types [e.g., acute kidney injury (AKI), chronic kidney disease (CKD), and AKI on CKD] were differentially associated with inpatient mortality.

METHODS

We utilized the nationwide inpatient sample, a nationally representative database, from 2007 to 2014. We included all hospitalizations with previously validated codes for cirrhosis or associated decompensated cirrhosis diagnoses. We defined kidney dysfunction types also from previously validated codes, and we grouped hospitalizations into the following diagnoses: normal, AKI, CKD, and AKI on CKD. Our primary outcome was inpatient mortality.

RESULTS

There were 1,293,779 hospitalizations with cirrhosis sampled in this study. Of these hospitalizations, 849,193 (66%) had normal kidney function, 176,418 (14%) had AKI, 157,600 (12%) had CKD, and 110,568 (9%) had AKI on CKD. We found that the proportion of hospitalizations with AKI, CKD, and AKI on CKD increased significantly throughout the study period (p < 0.001, test for trend for all). Kidney dysfunction type was differentially associated with inpatient mortality, even after adjustment: as compared to those with CKD, normal kidney function: OR 0.75 [95 CI 0.73-0.78], AKI: OR 2.40 [95 CI 2.32-2.48], and AKI on CKD: OR 1.66 [95 CI 1.60-1.72].

DISCUSSION

Using a nationally representative cohort of all hospitalizations with cirrhosis, our study highlights that the burden of kidney dysfunction, especially AKI, among hospitalizations with cirrhosis is rising, and the inclusion of kidney dysfunction type may be an opportunity to improve prognostication.

Management of hepatorenal syndrome in liver cirrhosis: a recent update

Hepatorenal syndrome (HRS) is a serious form of renal dysfunction in patients with cirrhosis and ascites. It is an important component of the acute-on-chronic liver failure (ACLF) syndrome. Significant recent changes in the understanding of the pathophysiology of renal dysfunction in cirrhosis include the role of inflammation in addition to hemodynamic changes. The term acute kidney injury (AKI) is now adopted to include all functional and structural forms of acute renal dysfunction in cirrhosis, with various stages describing the severity of the condition. Type 1 hepatorenal syndrome (HRS1) is renamed HRS-AKI, which is stage 2 AKI [doubling of baseline serum creatinine (sCr)] while fulfilling all other criteria of HRS1. Albumin is used for its volume expanding and anti-inflammatory properties to confirm the diagnosis of HRS-AKI. Vasoconstrictors are added to albumin as pharmacotherapy to improve the hemodynamics. Terlipressin, although not yet available in North America, is the most common vasoconstrictor used worldwide. Patients with high grade of ACLF treated with terlipressin are at risk for respiratory failure if there is pretreatment respiratory compromise. Norepinephrine is equally effective as terlipressin in reversing HRS1. Recent data show that norepinephrine may be administered outside the intensive care setting, but close monitoring is still required. There has been no improvement in overall or transplant-free survival shown with vasoconstrictor use, but response to vasoconstrictors with reduction in sCr is associated with improvement in survival. Non-responders to vasoconstrictor plus albumin will need liver transplantation as definite treatment with renal replacement therapy as a bridge therapy. Combined liver and kidney transplantation is recommended for patients with prolonged history of AKI, underlying chronic kidney disease or with hereditary renal conditions. Future developments, such as the use of biomarkers and metabolomics, may help to identify at risk patients with earlier diagnosis to allow for earlier treatment with improved outcomes.

Impact of Race-Adjusted Glomerular Filtration Rate Estimation on Eligibility for Simultaneous Liver-Kidney Transplantation

Estimated glomerular filtration rate (eGFR) is adjusted for Black race in commonly used formulas. This has potential implications for access to simultaneous liver-kidney transplantation (SLKT) as qualifying criteria rely on eGFR. We performed a retrospective study of United Network for Organ Sharing national transplant registry data between February 28, 2002, and March 31, 2019, to evaluate the proportion of Black patients who would be reclassified as meeting SLKT criteria (as defined per current policies) if race adjustment were removed from 2 prominent eGFR equations (Modification of Diet in Renal Disease-4 [MDRD-4] and Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI]). Of the 7937 Black patients listed for transplant during the study period, we found that 3.6% would have been reclassified as qualifying for chronic kidney disease (CKD)-related SLKT with removal of race adjustment for MDRD-4, and 3.0% would have been reclassified with CKD-EPI; this represented 23.7% and 18.7% increases in SLKT candidacy, respectively. Reclassification impacted women more than men (eg, 4.5% versus 3.0% by MDRD-4; P < 0.05). In an exploratory analysis, patients meeting SLKT criteria by race-unadjusted eGFR equations were significantly more likely to receive liver transplantation alone (LTA) compared with SLKT. Approximately 2.0% of reclassified patients required kidney transplantation within 1 year of LTA versus 0.3% of nonreclassified patients. In conclusion, race adjustment in eGFR equations may impact SLKT candidacy for 3.0% to 4.0% of Black patients listed for LTA overall. Approximately 2.0% of patients reclassified as meeting SLKT criteria require short-term post-LTA kidney transplantation. These data argue for developing novel algorithms for glomerular filtration rate estimation free of race to promote equity.

Chronic Kidney Disease After Liver Transplantation

Improved survival after liver transplantation has led to an aging cohort of recipients at risk of renal dysfunction. The etiology of renal dysfunction is typically multifactorial; calcineurin inhibitors nephrotoxicity, pretransplant renal dysfunction, and perioperative acute kidney injury are important risk factors. Metabolic complications such as hypertension, diabetes mellitus, and metabolic-associated fatty liver disease also contribute to the development of renal disease. Most LT recipients will eventually develop some degree of renal dysfunction. Criteria to select candidates for simultaneous liver and kidney transplantation have been established. Both delayed introduction of CNIs and renal-sparing immunosuppressive regimens may reduce progression of renal dysfunction.

The Interplay Between Nonalcoholic Fatty Liver Disease and Kidney Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide, involving approximately 25% of the general population and increasing in prevalence in patient populations afflicted with metabolic syndrome and type 2 diabetes. This article discusses the complex interplay between NAFLD and chronic kidney disease (CKD), as well as the underlying pathogenesis and mechanisms through which NAFLD and CKD are linked. Exploration of these sophisticated relationships and causative factors is essential to accurately assessing kidney function in patients with NAFLD, recommending pharmacologic treatment of disease, and identifying favorable avenues for future investigation.

Frailty and the Risk of Acute Kidney Injury Among Patients With Cirrhosis

Acute kidney injury (AKI) and frailty are major drivers of outcomes among patients with cirrhosis. What is unknown is the impact of physical frailty on the development of AKI. We included adults with cirrhosis without hepatocellular carcinoma listed for liver transplantation at nine US centers (n = 1,033). Frailty was assessed using the Liver Frailty Index (LFI); "frail" was defined by LFI ≥ 4.2. Chronic kidney disease as a baseline estimated glomerular filtration rate <60 mL/min/1.73 m2 . Our primary outcome, AKI, was defined as an increase in serum creatinine ≥0.3 mg/dL or a serum creatinine ≥1.5-fold increase. Wait-list mortality was defined as either a death on the wait list or removal for being too sick. We performed Cox regression analyses to estimate the hazard ratios (HRs) for AKI and wait-list mortality. Of 1,033 participants, 41% were frail and 23% had CKD. Twenty-one percent had an episode of AKI during follow-up. Frail versus nonfrail patients were more likely to develop AKI (25% vs. 19%) and wait-list mortality (21% vs. 13%) (P < 0.01 for each). In multivariable Cox regression, each of the following groups was associated with a higher risk of AKI as compared with not frail/no CKD: frail/no CKD (adjusted HR [aHR] = 1.87, 95% confidence interval [CI] = 1.29-2.72); not frail/CKD (aHR = 4.30, CI = 2.88-6.42); and frail/CKD (aHR = 4.85, CI = 3.33-7.07). We use a readily available metric, LFI, to identify those patients with cirrhosis most at risk for AKI. We highlight that serum creatinine and creatinine-based estimations of glomerular filtration rate may not fully capture a patient's vulnerability to AKI among the frail phenotype. Conclusion: Our work lays the foundation for implementing physical frailty in clinical practice to identify AKI earlier, implement reno-protective strategies, and expedite liver transplantation.

Role of Novel Kidney Biomarkers in Patients With Cirrhosis and After Liver Transplantation

Acute kidney injury (AKI) and chronic kidney disease (CKD) are important drivers of morbidity and mortality in patients with cirrhosis before and after liver transplantation (LT). In this review, we examine the role of novel kidney biomarkers for early recognition of kidney injury. Studies are limited by lack of reference standards, heterogeneous definitions of outcomes and biomarker cutoffs, and inconsistent diagnostic performance. Overall, a change in biomarker is more relevant than an absolute cutoff. Cystatin C and urinary neutrophil gelatinase-associated lipocalin (uNGAL) are the most studied candidate biomarkers and identify AKI or progression of AKI earlier than serum creatinine (sCr). Kidney injury molecule 1 and liver-type fatty acid-binding protein (L-FABP) also show potential. NGAL and interleukin 18 may play a role in differentiating acute tubular necrosis from other forms of AKI. Combining novel biomarkers with the Model for End-Stage Liver Disease score may assist prognosis. Persistent elevations in select markers (eg, NGAL) can portend irreversible injury. Several pretransplantation markers (including sCr) predict posttransplantation kidney dysfunction. Pretransplantation assessment of clinical factors (eg, age, diabetes) and novel markers (osteopontin and tissue inhibitor of metalloproteinases 1 [TIMP-1]) may predict renal kidney recovery after LT. Intraoperative changes in biomarkers predict early post-LT AKI. Prediction of CKD remains difficult, although a combination of biomarkers (eg, beta-2 microglobulin, CD40) is promising. Novel biomarkers have yet to replace sCr in guideline-based evaluation and management of kidney dysfunction in patients with cirrhosis. We propose a theoretical framework for practical incorporation of these biomarkers that considers patient characteristics (risk for irreversible injury), markers of functional and structural change, and assessment of the AKI-CKD continuum to identify patients at the highest risk for progressive kidney disease before and after LT.

The changing impact of pre-liver transplant renal dysfunction on post-transplant survival: results of 2 decades from a single center

INTRODUCTION AND OBJECTIVES

Renal dysfunction before liver transplantation (LT) is associated with higher post-LT mortality. We aimed to study if this association still persisted in the contemporary transplant era.

MATERIALS AND METHODS

We retrospectively reviewed data on 2871 primary LT performed at our center from 1998 to 2018. All patients were listed for LT alone and were not considered to be simultaneous liver-kidney (SLK) transplant candidates. SLK recipients and those with previous LT were excluded. Patients were grouped into 4 eras: era-1 (1998-2002, n = 488), era-2 (2003-2007, n = 889), era-3 (2008-2012, n = 703) and era-4 (2013-2018, n = 791). Pre-LT renal dysfunction was defined as creatinine (Cr) >1.5 mg/dl or on dialysis at LT. The effect of pre-LT renal dysfunction on post-LT patient survival in each era was examined using Kaplan Meier estimates and univariate and multivariate Cox proportional hazard analyses.

RESULTS

Pre-LT renal dysfunction was present in 594 (20%) recipients. Compared to patients in era-1, patients in era-4 had higher Cr, lower eGFR and were more likely to be on dialysis at LT (P < 0.001). Pre-LT renal dysfunction was associated with worse 1, 3 and 5-year survival in era-1 and era-2 (P < 0.005) but not in era-3 or era-4 (P = 0.13 and P = 0.08, respectively). Multivariate analysis demonstrated the lack of independent effect of pre-LT renal dysfunction on post-LT mortality in era-3 and era-4. A separate analysis using eGFR <60 mL/min/1.73 m² at LT to define renal dysfunction showed similar results.

CONCLUSIONS

Pre-LT renal dysfunction had less impact on post-LT survival in the contemporary transplant era.

An Essential Guide for Managing Post-Liver Transplant Patients: What Primary Care Physicians Should Know

With long-term survival after liver transplantation becoming the rule, care for medical problems arising over time in liver-transplanted patients gained increasing importance. The most common causes of death occurring more than 1 year after liver transplantation are unrelated to liver diseases and facilitated by immunosuppressive treatments; examples are malignancies, renal failure, and cardiovascular, metabolic, and infectious diseases. Recipients receive life-long follow-up care at transplant centers, however, the increasing number of liver-transplanted patients is saturating the health care supply that transplant centers have to offer. Primary care physicians are increasingly exposed to liver-transplanted patients, even in the early periods after transplant, and an understanding of the most common risks and complications faced by these patients would enhance their care. This article reviews the long-term care of liver transplant recipients, emphasizing the key internal medicine-related issues that should be known by primary care physicians. A specific section is devoted to implementing strategies to involve these physicians in the long-term follow-up of liver-transplanted patients in close collaboration with transplant hepatologists.

Early transplantation maximizes survival in severe acute-on-chronic liver failure: Results of a Markov decision process model

Background & Aims

Uncertainties exist surrounding the timing of liver transplantation (LT) among patients with acute-on-chronic liver failure grade 3 (ACLF-3), regarding whether to accept a marginal quality donor organ to allow for earlier LT or wait for either an optimal organ offer or improvement in the number of organ failures, in order to increase post-LT survival.

Methods

We created a Markov decision process model to determine the optimal timing of LT among patients with ACLF-3 within 7 days of listing, to maximize overall 1-year survival probability.

Results

We analyzed 6 groups of candidates with ACLF-3: patients age ≤60 or >60 years, patients with 3 organ failures alone or 4-6 organ failures, and hepatic or extrahepatic ACLF-3. Among all groups, LT yielded significantly greater overall survival probability vs. remaining on the waiting list for even 1 additional day (p <0.001), regardless of organ quality. Creation of 2-way sensitivity analyses, with variation in the probability of receiving an optimal organ and expected post-transplant mortality, indicated that overall survival is maximized by earlier LT, particularly among candidates >60 years old or with 4-6 organ failures. The probability of improvement from ACLF-3 to ACLF-2 does not influence these recommendations, as the likelihood of organ recovery was less than 10%.

Conclusion

During the first week after listing for patients with ACLF-3, earlier LT in general is favored over waiting for an optimal quality donor organ or for recovery of organ failures, with the understanding that the analysis is limited to consideration of only these 3 variables.

Lay summary

In the setting of grade 3 acute-on-chronic liver failure (ACLF-3), questions remain regarding the timing of transplantation in terms of whether to proceed with liver transplantation with a marginal donor organ or to wait for an optimal liver, and whether to transplant a patient with ACLF-3 or wait until improvement to ACLF-2. In this study, we used a Markov decision process model to demonstrate that earlier transplantation of patients listed with ACLF-3 maximizes overall survival, as opposed to waiting for an optimal donor organ or for improvement in the number of organ failures.

A meta-analysis on the prevalence of chronic kidney disease in liver transplant candidates and its associated risk factors and outcomes

Pre-liver transplant (LT) chronic kidney disease (CKD) has emerged as a leading cause of post-operative morbidity. We aimed to report the prevalence, associated risk factors, and clinical outcomes in patients with pre-LT CKD. Meta-analysis and systematic review were conducted for included cohort and cross-sectional studies. Studies comparing healthy and patients with s pre-LT CKD were included. Outcomes were assessed with pooled hazard ratios. 15 studies were included, consisting of 82,432 LT patients and 26,754 with pre-LT CKD. Pooled prevalence of pre-LT CKD was 22.35% (CI: 15.30%-32.71%). Diabetes mellitus, hypertension, viral hepatitis, and non-alcoholic fatty liver disease, and older age were associated with increased risk of pre-LT CKD: (OR 1.72 CI: 1.15-2.56, P = 0.01), (OR 2.23 CI: 1.76-2.83, P < 0.01), (OR 1.09; CI: 1.05-1.13, P < 0.01), (OR 1.73; CI: 1.10-2.71 P = 0.03), and (MD: 2.92 years; CI: 1.29-4.55years; P < 0.01) respectively. Pre-LT CKD was significantly associated with increased mortality (HR 1.38; CI: 1.2-1.59; P < 0.01), post-LT end-stage renal disease and post-LT CKD. Almost a quarter of pre-LT patients have CKD and it is significantly associated with post-operative morbidity and mortality. However, long-term outcomes remain unclear due to a lack of studies reporting such outcomes.

Current State of Multiorgan Transplantation and Implications for Future Practice and Policy

The incidence of kidney dysfunction has increased in liver transplant and heart transplant candidates, reflecting a changing patient population and allocation policies that prioritize the most urgent candidates. A higher burden of pretransplant kidney dysfunction has resulted in a substantial rise in the utilization of multiorgan transplantation (MOT). Owing to a shortage of available deceased donor kidneys, the increased use of MOT has the potential to disadvantage kidney-alone transplant candidates, as current allocation policies generally provide priority for MOT candidates above all kidney-alone transplant candidates. In this review, the implications of kidney disease in liver transplant and heart transplant candidates is reviewed, and current policies used to allocate organs are discussed. Important ethical considerations pertaining to MOT allocation are examined, and future policy modifications that may improve both equity and utility in MOT policy are considered.

Temporal Trends and Evolving Outcomes After Simultaneous Liver-Kidney Transplantation: Results from the US SLKT Consortium

We aimed to understand the contemporary changes in the characteristics and the determinants of outcomes among simultaneous liver-kidney transplantation (SLKT) recipients at 6 liver transplantation centers in the United States. We retrospectively enrolled SLKT recipients between 2002 and 2017 in the US Multicenter SLKT Consortium. We analyzed time-related trends in recipient characteristics and outcomes with linear regression and nonparametric methods. Clustered Cox regression determined the factors associated with 1-year and overall survival. We enrolled 572 patients. We found significant changes in the clinical characteristics of SLKT recipients: as compared with 2002, recipients in 2017 were older (59 versus 52 years; P < 0.001) and more likely to have chronic kidney disease (71% versus 33%; P < 0.001). There was a marked improvement in 1-year survival during the study period: 89% in 2002 versus 96% in 2017 (P < 0.001). We found that the drivers of 1-year mortality were SLKT year, hemodialysis at listing, donor distance, and delayed kidney allograft function. The drivers of overall mortality were an indication of acute kidney dysfunction, body mass index, hypertension, creatinine at SLKT, ventilation at SLKT, and donor quality. In this contemporary cohort of SLKT recipients, we highlight changes in the clinical characteristics of recipients. Further, we identify the determinants of 1-year and overall survival to highlight the variables that require the greatest attention to optimize outcomes.

Comanagement With Nephrologist Care Is Associated With Fewer Cardiovascular Events Among Liver Transplant Recipients With Chronic Kidney Disease

Chronic kidney disease (CKD) is associated with cardiovascular (CV) events, a leading complication in liver transplant recipients (LTRs). Timely subspecialty care is associated with improved clinical outcomes in patients with CKD. This study sought to assess associations between nephrology comanagement and CV events among LTRs at risk for or with CKD.

METHODS

LTRs with CKD plus those at risk were identified in an inception cohort at a single tertiary care network between 2010 and 2016, using electronic health record data and manual chart review. CKD was defined as estimated glomerular filtration rate <60 mL/min/1.73 m2 or International Classification of Diseases 9th or 10th revision code for CKD and at-risk CKD as estimated glomerular filtration rate 60-89 mL/min/1.73 m2. Cox proportional hazard models assessed the association between nephrology comanagement and CV events among LTRs with or at risk for CKD.

RESULTS

Among 602 LTRs followed for up to 6 y posttransplant, prevalence of CKD plus those at risk increased yearly (71% in year 1, 86% in year 6) (P < 0.0001). Rates of nephrology comanagement decreased yearly posttransplant (35% in year 1, 28% in year 6). In multivariable models, nephrology comanagement was associated with lower CV events (adjusted hazard ratio, 0.57; 95% confidence interval, 0.33-0.99).

CONCLUSIONS

Among LTRs with CKD, nephrology comanagement may be associated with lower CV events. A prospective study is needed to identify the reasons for improved outcomes and barriers to nephrology referral.

Post-Liver Transplant Early Allograft Dysfunction Modifies the Effect of Pre-Liver Transplant Renal Dysfunction on Post-Liver Transplant Survival

Pre-liver transplantation (LT) renal dysfunction is associated with poor post-LT survival. We studied whether early allograft dysfunction (EAD) modifies this association. Data on 2,856 primary LT recipients who received a transplant between 1998 and 2018 were retrospectively reviewed. Patients who died within the first post-LT week or received multiorgan transplants and previous LT recipients were excluded. EAD was defined as (1) total bilirubin ≥ 10 mg/dL on postoperative day (POD) 7, (2) international normalized ratio ≥1.6 on POD 7, and/or (3) alanine aminotransferase or aspartate aminotransferase ≥2000 IU/mL in the first postoperative week. Pre-LT renal dysfunction was defined as serum creatinine >1.5 mg/dL or on renal replacement therapy at LT. Patients were divided into 4 groups according to pre-LT renal dysfunction and post-LT EAD development. Recipients who had both pre-LT renal dysfunction and post-LT EAD had the worst unadjusted 1-year, 3-year, and 5-year post-LT patient and graft survival, whereas patients who had neither renal dysfunction nor EAD had the best survival (P < 0.001). After adjusting for multiple factors, the risk of death was significantly higher only in those with both pre-LT renal dysfunction and post-LT EAD (adjusted hazard ratio [aHR], 2.19; 95% confidence interval [CI], 1.58-3.03; P < 0.001), whereas those with renal dysfunction and no EAD had a comparable risk of death to those with normal kidney function at LT (aHR, 1.12; 95% CI, 0.86-1.45; P = 0.41). Results remained unchanged when pre-LT renal dysfunction was redefined using different glomerular filtration rate cutoffs. Pre-LT renal dysfunction negatively impacts post-LT survival only in patients who develop EAD. Livers at higher risk of post-LT EAD should be used with caution in recipients with pre-LT renal dysfunction.

Predicting survival after liver transplantation in patients with hepatocellular carcinoma using the LiTES-HCC score

BACKGROUND & AIMS

Liver transplant priority in the US and Europe follows the 'sickest-first' principle. However, for patients with hepatocellular carcinoma (HCC), priority is based on binary tumor criteria to expedite transplant for patients with 'acceptable' post-transplant outcomes. Newer risk scores developed to overcome limitations of these binary criteria are insufficient to be used for waitlist priority as they focus solely on HCC-related pre-transplant variables. We sought to develop a risk score to predict post-transplant survival for patients using HCC- and non-HCC-related variables.

METHODS

We performed a retrospective cohort study using national registry data on adult deceased-donor liver transplant (DDLT) recipients with HCC from 2/27/02-12/31/18. We fit Cox regression models focused on 5- and 10-year survival to estimate beta coefficients for a risk score using manual variable selection. We then calculated absolute predicted survival time and compared it to available risk scores.

RESULTS

Among 6,502 adult DDLT recipients with HCC, 11 variables were selected in the final model. The AUCs at 5- and 10-years were: 0.62, 95% CI 0.57-0.67 and 0.65, 95% CI 0.58-0.72, which was not statistically significantly different to the Metroticket and HALT-HCC scores. The LiTES-HCC score was able to discriminate patients based on post-transplant survival among those meeting Milan and UCSF criteria.

CONCLUSION

We developed and validated a risk score to predict post-transplant survival for patients with HCC. By including HCC- and non-HCC-related variables (e.g., age, chronic kidney disease), this score could allow transplant professionals to prioritize patients with HCC in terms of predicted survival. In the future, this score could be integrated into survival benefit-based models to lead to meaningful improvements in life-years at the population level.

LAY SUMMARY

We created a risk score to predict how long patients with liver cancer will live if they get a liver transplant. In the future, this could be used to decide which waitlisted patients should get the next transplant.

Early Kidney Allograft Failure After Simultaneous Liver-kidney Transplantation: Evidence for Utilization of the Safety Net?

BACKGROUND

With the implementation of the "Safety Net," we aimed to determine the impact of simultaneous liver-kidney transplantation (SLKT), as compared to kidney transplant after liver transplant (KALT), on kidney allograft failure (KF).

METHODS

An analysis of the UNOS database for all adult patients who received either an SLKT or KALT from 2002 to 2017. The outcomes were 90-day KF and 1-year KF (as reported to UNOS, at 90- and 365-day postkidney transplant, respectively). We compared the following groups of patients: SLKT <25 (SLKT with final model for end-stage liver disease [MELD] <25), SLKT25/35 (MELD ≥25/<35), and SLKT35 (MELD ≥35) to KALT.

RESULTS

Of the 6276 patients, there were 1481 KALT, 1579 SLKT <25, 1832 SLKT25/35, and 1384 SLKT ≥35. The proportion of patients with 90-day and 1-year KF increased significantly among the KALT, SLKT <25, SLKT25/35, and SLKT ≥35 groups (P < 0.001; test for trend): 90-day KF: 3.3% versus 5.5% versus 7.3% versus 9.3% and 1-year KF: 5.1% versus 9.4% versus 12.3% versus 14.7%. After adjustment and compared with KALT, beginning at an MELD ≥25 those undergoing SLKT had significantly higher risk of 90-day and 1-year KF: 90-day KF: SLKT25/35: hazard ratio, 1.6(1.0-2.3); SLKT ≥35: 2.1(1.3-3.3); 1-year KF: SLKT25/35: hazard ratio, 1.7(1.2-2.4); SLKT ≥35: 2.1(1.5-3.0).

CONCLUSIONS

As compared to KALT recipients, SLKT recipients with an MELD ≥25 had significantly higher risk of early KF. Given the now well-established "Safety Net," KALT may serve as an opportunity to improve kidney outcomes in patients with an MELD ≥25.

Chronic renal dysfunction in cirrhosis: A new frontier in hepatology

Chronic kidney disease (CKD) in patients with liver cirrhosis has become a new frontier in hepatology. In recent years, a sharp increase in the diagnosis of CKD has been observed among patients with cirrhosis. The rising prevalence of risk factors, such as diabetes, hypertension and nonalcoholic fatty liver disease, appears to have contributed significantly to the high prevalence of CKD. Moreover, the diagnosis of CKD in cirrhosis is now based on a reduction in the estimated glomerular filtration rate of < 60 mL/min over more than 3 mo. This definition has resulted in a better differentiation of CKD from acute kidney injury (AKI), leading to its greater recognition. It has also been noted that a significant proportion of AKI transforms into CKD in patients with decompensated cirrhosis. CKD in cirrhosis can be structural CKD due to kidney injury or functional CKD secondary to circulatory and neurohormonal imbalances. The available literature on combined cirrhosis-CKD is extremely limited, as most attempts to assess renal dysfunction in cirrhosis have so far concentrated on AKI. Due to problems related to glomerular filtration rate estimation in cirrhosis, the absence of reliable biomarkers of CKD and technical difficulties in performing renal biopsy in advanced cirrhosis, CKD in cirrhosis can present many challenges for clinicians. With combined hepatorenal dysfunctions, fluid mobilization becomes problematic, and there may be difficulties with drug tolerance, hemodialysis and decision-making regarding the need for liver vs simultaneous liver and kidney transplantation. This paper offers a thorough overview of the increasingly known CKD in patients with cirrhosis, with clinical consequences and difficulties occurring in the diagnosis and treatment of such patients.

Health Care Resource Use and Cost Burden of Chronic Kidney Disease in Patients With Chronic Liver Disease: A Real-World Claims Analysis

Chronic Liver Disease (CLD) is associated with an increased risk of chronic kidney disease (CKD). However, the health care burden of CKD in the CLD spectrum is unknown. We aimed to evaluate the health care use and cost burdens associated with CKD in patients with CLD in the United States by using real-world claims data. We analyzed data from the Truven Health MarketScan Commercial Claims database from 2010 to 2015. A total of 19,664 patients with CLD with or without comorbid CKD were identified using International Classification of Diseases, Ninth Revision, codes and matched 1:1 by sociodemographic characteristics and comorbidities using propensity scores. Total and service-specific unadjusted and adjusted health care parameters were analyzed for the 12 months following an index date selected at random to capture whole disease burdens. In CLD, comorbid CKD was associated with a higher annual number of claims per person (CKD vs. no CKD, 69 vs. 55) and higher total annual median health care costs (CKD vs. no CKD, $21,397 vs. $16,995). A subanalysis stratified by CKD category showed that health care use and cost burden in CLD increased with disease stage, with a peak 12-month median cost difference of $77,859 in patients on dialysis. The adjusted per person annual health care cost was higher for CKD cases compared to controls ($35,793 vs. $24,048, respectively; P < 0.0001). Stratified by the type of CLD, the highest between-group adjusted cost differences were for cirrhosis, viral hepatitis, hemochromatosis, and nonalcoholic fatty liver disease. Conclusion: CKD is a cost multiplier in CLD. The CKD health care burden in liver disease differs by the type of CLD. Improved CKD screening and proactive treatment interventions for at-risk patients can limit the excess burden associated with CKD in patients with CLD.