Impact of MELD-based allocation on end-stage renal disease after liver transplantation

Novel indications for referral and care for simultaneous liver kidney transplant recipients

PURPOSE OF REVIEW

Kidney dysfunction is challenging in liver transplant candidates to determine whether it is reversible or not. This review focuses on the pertinent data on how to best approach liver transplant candidates with kidney dysfunction in the current era after implementing the simultaneous liver kidney (SLK) allocation policy and safety net.

RECENT FINDINGS

The implementation of the SLK policy inverted the steady rise in SLK transplants and improved the utilization of high-quality kidneys. Access to kidney transplantation following liver transplant alone (LTA) increased with favorable outcomes. Estimating GFR in liver transplant candidates remains challenging, and innovative methods are needed. SLK provided superior patient and graft survival compared to LTA only for patients with advanced CKD and dialysis at least 3 months. SLK can provide immunological protection against kidney rejection in highly sensitized candidates. Post-SLK transplant care is complex, with an increased risk of complications and hospitalization.

SUMMARY

The SLK policy improved kidney access and utilization. Transplant centers are encouraged, under the safety net, to reserve SLK for liver transplant candidates with advanced CKD or dialysis at least 3 months while allowing lower thresholds for highly sensitized patients. Herein, we propose a practical approach to liver transplant candidates with kidney dysfunction.

Risk and prediction of kidney failure early after liver transplantation

BACKGROUND

Kidney disease is common after liver transplantation (LT), but postoperative kidney failure is difficult to predict. Current guidelines recommend simultaneous liver-kidney transplantation (SLKT) in patients with pre-LT estimated glomerular filtration rate (eGFR) below 30-40 mL/min, which might be too liberal. The aim of this study was to evaluate the risk of kidney failure after LT. We also assessed the predictive ability of pretransplantation eGFR using various equations.

METHODS

This single-center study included patients undergoing primary LT 2006-2020. Patients undergoing simultaneous liver-kidney transplantations or on dialysis before LT were analysed separately. We calculated 5 different eGFR equations measured just before LT and assessed their predictive ability using Kaplan-Meier cumulative incidence estimates.

RESULTS

Among 556 LT patients with a median follow-up of 5.0 years (IQR 2.0-8.5), 20 developed kidney failure during follow-up, 7 of them within 1-year post LT. Six of these 7 suffered from major perioperative complications. Depending on the eGFR equation used, the incidence of kidney failure within 1-year was 3.9-6.7% at pre-LT eGFR-values <30 mL/min, 1.2-3.1% at eGFR 30-60 mL/min, and 0.6-0.9% at eGFR >60 mL/min.

CONCLUSIONS

Kidney failure within 1-year post-LT could not be reliably predicted by pre-LT eGFR. However, kidney failure was uncommon even in patients with severely reduced pre-LT glomerular filtration rate (eGFR <30 mL/min), and extremely rare in patients unaffected by major perioperative complications. Our data prompts further consideration regarding the guidelines for SLKT in patients with a reduced preoperative eGFR.

Combined liver-kidney transplantation in pediatric patients

Combined liver-kidney transplantation (CLKT) is a surgical procedure that involves transplanting both liver and kidney organs. There are two types of CLKT: simultaneous liver-kidney transplantation (smLKT) and sequential LKT (sqLKT). CLKT accounts for a small percentage of liver transplantations (LTs), particularly in pediatric cases. Nevertheless, the procedure has demonstrated excellent outcomes, with high survival rates and lower rejection rates. The main indications for CLKT in pediatric patients differ somewhat from that in adults, in which end-stage kidney disease after LT is the major indication. In children, congenital diseases are common reason for performing CLKT; the examples of such diseases include autosomal recessive polycystic kidney disease with congenital hepatic fibrosis which equally affects both organs, and primary hyperoxaluria type 1, a primary liver disease leading kidney failure. The decision between smLKT or sqLKT depends on the dominant organ failure, the specific pathophysiology, and available organ sources. However, there remain significant surgical and societal challenges surrounding CLKT. Innovations in pharmacology and genetic engineering have decreased the necessity for CLKT in early-diagnosed cases without portal hypertension or kidney replacement therapy. Nonetheless, these advancements are not universally accessible. Therefore, decision-making algorithms should be crafted, considering region-specific organ allocation systems and prevailing medical environments.

Evolving challenges with long-term care of liver transplant recipients

The number of liver transplants (LT) performed worldwide continues to rise, and LT recipients are living longer post-transplant. This has led to an increasing number of LT recipients requiring lifelong care. Optimal care post-LT requires careful attention to both the allograft and systemic issues that are more common after organ transplantation. Common causes of allograft dysfunction include rejection, biliary complications, and primary disease recurrence. While immunosuppression prevents rejection and reduces incidences of some primary disease recurrence, it has detrimental systemic effects. Most commonly, these include increased incidences of metabolic syndrome, various malignancies, and infections. Therefore, it is of utmost importance to optimize immunosuppression regimens to prevent allograft dysfunction while also decreasing the risk of systemic complications. Institutional protocols to screen for systemic disease and heightened clinical suspicion also play an important role in providing optimal long-term post-LT care. In this review, we discuss these common complications of LT as well as unique considerations when caring for LT recipients in the years after transplant.

Chronic Kidney Disease After Liver Transplantation

Chronic kidney disease among liver transplant recipients is common and associated with an increased mortality risk. Several risk factors and causes for the development of chronic kidney disease have been identified. They can be divided into perioperative factors, such as unresolved acute kidney injury; donor-related factors, such as the use of extended criteria liver allografts; and recipient-related factors, such as the use of calcineurin inhibitors and the presence of metabolic syndrome, diabetes, and obesity. There is a bimodal progression, more prominent during the initial post-transplant months, followed by a gradual but progressive decline over the subsequent years. Management strategies to prevent and treat chronic kidney disease in the general population can be reasonably applied to the liver transplant population and include addressing comorbidities such as hypertension and diabetes. Strategies to minimize or withdraw calcineurin inhibitors from the immunosuppressive regimen can slow progression of kidney dysfunction. Patients with advanced chronic kidney disease should be considered for kidney transplantation due to its survival advantage. Allocation policy in the United States confers safety-net allocation priority for liver transplant recipients who develop advanced chronic kidney disease within the first year of liver transplantation.

The Renal Histological Correlates of Refractory Renal Dysfunction After Liver Transplantation

Background

Kidney dysfunction is common after liver transplantation (LT) and is often attributed to calcineurin inhibitors (CNIs). Very few studies have looked at histological causes.

Material and methods

The study is a retrospective analysis of histological findings and diagnosis in all patients who underwent a kidney biopsy after LT from 2010 to 2020. Data are shown as mean ± standard deviation or medians (25-75 interquartile range).

Results

The study cohort consisted of 26 patients (25 males, 1 female), aged 55 ± 7 years at the time of the kidney biopsy. Kidney biopsies were done at 27.5 (6.7-60.7) months after LT. At the time of the kidney biopsy, the median serum creatinine was 2.10 (1.50-2.86) mg/dl and proteinuria was 3.8 (1.8-5.9) gm/day. Twenty-four (92%) patients were on CNIs. The diagnoses on kidney biopsies were diabetic nephropathy (n = 7), focal segmental glomerulosclerosis (n = 4), CNI nephrotoxicity (n = 3), IgA nephropathy (n = 4), chronic glomerulonephritis (n = 3), hypertensive nephropathy (n = 1), membranous glomerulonephritis (n = 1), acute on chronic interstitial nephritis (n = 1), and C1q nephropathy (n = 1), and the sample was inadequate in one patient. A total of sixteen patients had progression of kidney disease. The kidney function remained stable/improved in 6 (23%) patients, follow-up data were not available for 4 patients. Fourteen (53.8%) patients (including one with CNI nephrotoxicity) required hemodialysis at 13.5 (5.7-29) months after the kidney biopsy.

Conclusion

Although the kidney biopsy diagnosed the cause of unexplained renal insufficiency in LT recipients, the majority of patients progressed to end-stage renal disease despite treatment modifications. The use of CNIs was an uncommon cause of renal impairment.

COVID-19 and severity of liver diseases: Possible crosstalk and clinical implications

COVID-19-infected individuals and those who recovered from the infection have been demonstrated to have elevated liver enzymes or abnormal liver biochemistries, particularly with preexisting liver diseases, liver metabolic disorders, viral hepatitis, and other hepatic comorbidities. However, possible crosstalk and intricate interplay between COVID-19 and liver disease severity are still elusive, and the available data are murky and confined. Similarly, the syndemic of other blood-borne infectious diseases, chemical-induced liver injuries, and chronic hepatic diseases continued to take lives while showing signs of worsening due to the COVID-19 crisis. Moreover, the pandemic is not over yet and is transitioning to becoming an epidemic in recent years; hence, monitoring liver function tests (LFTs) and assessing hepatic consequences of COVID-19 in patients with or without liver illnesses would be of paramount interest. This pragmatic review explores the correlations between COVID-19 and liver disease severity based on abnormal liver biochemistries and other possible mechanisms in individuals of all ages from the emergence of the COVID-19 pandemic to the post-pandemic period. The review also alludes to clinical perspectives of such interactions to curb overlapping hepatic diseases in people who recovered from the infection or living with long COVID-19.

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.

Pathogen distribution and risk factors of bacterial and fungal infections after liver transplantation

OBJECTIVES

Liver transplant recipients have a high rate of postoperative infection, and identification of patients at high risk for bacterial and fungal infections will help prevent disease and improve long-term outcomes for them. This study aims to understand the composition, distribution, prognosis of bacterial and fungal infections within 2 months after liver transplantation and to analyze their risk factors.

METHODS

The data of pathogen composition, distribution, and prognosis of bacterial and fungal infections among liver transplant recipients in the Third Xiangya Hospital of Central South University from May 2020 to October 2021 were collected, and the risk factors for these infections were analyzed.

RESULTS

A total of 106 episodes of bacterial or fungal infections occurred in 71.4% of liver transplant recipients (75/105). Gram-negative bacteria were the dominant pathogenic bacteria (49/106, 46.2%), followed by Gram-positive bacteria (31/106, 29.2%). The most common Gram-negative bacterium was Acinetobacter baumannii (13/106, 12.3%). The most common Gram-positive bacterium was Enterococcus faecium (20/106, 18.9%). The most common infections were pulmonary (38/105, 36.2%) and multiple site infections (30/105, 28.6%). Six (6/105, 5.7%) patients with infections died within 2 months after liver transplantation. Univariate analysis showed that the model for end-stage liver disease (MELD) score ≥25, antibiotic use within half a month before transplantation, infections within 2 months prior to transplantation, intraoperative red blood cell infusion≥8 U, indwelling urinary tract catheter ≥4 days after transplantation, and the dosage of basiliximab use ≥40 mg were associated with infections. Multivariate logistic regression analysis revealed that only infections within 2 months prior to transplantation (OR=5.172, 95% CI 1.905-14.039, P<0.01) was an independent risk factor for bacterial and fungal infections after liver transplantation. Postoperative bacterial and fungal infections were reduced in liver transplant recipients receiving basiliximab ≥40 mg (OR=0.197, 95% CI: 0.051-0.762, P<0.05).

CONCLUSIONS

The incidence of bacterial and fungal infections is high in the early stage after liver transplantation, and the mortality after infection is significantly higher than that of non-infected patients. The most common infection is respiratory infection, and the dominant pathogens is Gram-negative bacteria. Patients infected within 2 months prior to liver transplantation are prone to bacterial and fungal infections. Standard use of basiliximab can reduce the incidence of infections after liver transplantation.

Non-Renal Risk Factors for Chronic Kidney Disease in Liver Recipients with Functionally Intact Kidneys at 1 Month

Chronic kidney disease (CKD) is a critical complication of liver transplants, of which non-renal risk factors are not fully understood yet. This study aimed to reveal pre- and post-transplant risk factors for CKD (<60 mL/min/1.73 m2), examining liver recipients with functionally intact kidneys one month after grafting using nationwide cohort data. Baseline risk factors were analyzed with multivariable Cox regression analyses and post-transplant risk factors were investigated with the time-dependent Cox model and matched analyses of time-conditional propensity scores. Of the 2274 recipients with a one-month eGFR ≥ 60 mL/min/1.73 m2, 494 (22.3%) developed CKD during a mean follow-up of 36.6 ± 14.4 months. Age, female sex, lower body mass index, pre-transplant diabetes mellitus, and lower performance status emerged as baseline risk factors for CKD. Time-dependent Cox analyses revealed that recurrent hepatocellular carcinoma (HR = 1.93, 95% CI 1.06−3.53) and infection (HR = 1.44, 95% CI 1.12−1.60) were significant post-transplant risk factors for CKD. Patients who experienced one of those factors showed a significantly higher risk of subsequent CKD compared with the matched controls who lacked these features (p = 0.013 for recurrent hepatocellular carcinoma, and p = 0.003 for infection, respectively). This study clarifies pre- and post-transplant non-renal risk factors, which lead to renal impairment after LT independently from patients’ renal functional reserve.

Intraoperative risk factors of acute kidney injury after liver transplantation

Acute kidney injury (AKI) is one of the most common complications of liver transplantation (LT). We examined the impact of intraoperative management on risk for AKI following LT. In this retrospective observational study, we linked data from the electronic health record with standardized transplant outcomes. Our primary outcome was stage 2 or 3 AKI as defined by Kidney Disease Improving Global Outcomes guidelines within the first 7 days of LT. We used logistic regression models to test the hypothesis that the addition of intraoperative variables, including inotropic/vasopressor administration, transfusion requirements, and hemodynamic markers improves our ability to predict AKI following LT. We also examined the impact of postoperative AKI on mortality. Of the 598 adult primary LT recipients included in our study, 43% (n = 255) were diagnosed with AKI within the first 7 postoperative days. Several preoperative and intraoperative variables including (1) electrolyte/acid-base balance disorder (International Classification of Diseases, Ninth Revision codes 253.6 or 276.x and International Classification of Diseases, Tenth Revision codes E22.2 or E87.x, where x is any digit; adjusted odds ratio [aOR], 1.917, 95% confidence interval [CI], 1.280-2.869; p = 0.002); (2) preoperative anemia (aOR, 2.612; 95% CI, 1.405-4.854; p = 0.002); (3) low serum albumin (aOR, 0.576; 95% CI, 0.410-0.808; p = 0.001), increased potassium value during reperfusion (aOR, 1.513; 95% CI, 1.103-2.077; p = 0.01), and lactate during reperfusion (aOR, 1.081; 95% CI, 1.003-1.166; p = 0.04) were associated with posttransplant AKI. New dialysis requirement within the first 7 days postoperatively predicted the posttransplant mortality. Our study identified significant association between several potentially modifiable variables with posttransplant AKI. The addition of intraoperative data did not improve overall model discrimination.

Renal safety of tenofovir disoproxil fumarate and entecavir in liver transplant patients: a nationwide Korean registry study

BACKGROUND AND AIMS

Tenofovir disoproxil fumarate (TDF) and entecavir (ETV) have been recommended after liver transplantation to prevent recurrence of hepatitis B virus infection. Despite its proven efficacy, the renal safety of TDF has not been established in liver transplant recipients. We aimed to compare the effects of TDF and ETV on renal function in liver transplant recipients and to evaluate risk factors for renal dysfunction after liver transplantation.

METHODS

This is a retrospective, observational multicenter study of data from the Korean Organ Transplantation Registry. We included adults who underwent liver transplantation for hepatitis B virus-related complications from April 2014 to December 2017 and received TDF or ETV post-transplantation. Renal dysfunction was defined as an estimated glomerular filtration rate decline by at least 20% from baseline (1 month post-transplantation). Median duration of follow-up was 29 months (interquartile range 19-42).

RESULTS

A total of 804 liver transplant patients were included. The cumulative probability of renal dysfunction was significantly higher in the TDF group than in the ETV group. Multivariable analysis confirmed that TDF was independently associated with an increased risk of renal dysfunction (hazard ratio = 1.47, 95% confidence interval 1.12-1.92; p = 0.005). Independent risk factors for renal dysfunction included older age, worse baseline renal function, and low body mass index. Overall survival rate was significantly lower in patients with renal dysfunction than in those without.

CONCLUSIONS

In this nationwide study, the use of TDF was associated with an increased risk of renal dysfunction, when compared with ETV.

Kidney Allocation Issues in Liver Transplantation Candidates with Chronic Kidney Disease and Severe Kidney Liver Injury

The number of liver transplant candidates with concomitant renal disease has been steadily rising since the implementation of MELD-based allocation in 2002. Consequently, the number of simultaneous liver-kidney (SLK) transplants being performed each year has also increased. However, the establishment of well-defined criteria for when to choose SLK over liver transplant alone has lagged behind. The lack of clear guidelines has worsened an already large shortage of transplantable kidneys. This article further explores the rationale for and outlines the implementation of the SLK allocation policy.

[Kidney failure after liver transplantation]

One third of cirrhotic patients present impaired kidney function. It has multifactorial causes and has a harmful effect on patients' morbi-mortality before and after liver transplant. Kidney function does not improve in all patients after liver transplantation and liver-transplant recipients are at high risk of developing chronic kidney disease. Causes for renal dysfunction can be divided in three groups: preoperative, peroperative and postoperative factors. To date, there is no consensus for the modality of evaluation the risk for chronic kidney disease after liver transplantation, and for its prevention. In the present review, we describe the outcome of kidney function after liver transplantation, and the prognostic factors of chronic kidney disease to determine a risk stratification for each patient. Furthermore, we discuss therapeutic options to prevent kidney dysfunction in this setting, and highlight the indications of combined liver-kidney transplantation.

The application of artificial intelligence in hepatology: A systematic review

The integration of human and artificial intelligence (AI) in medicine has only recently begun but it has already become obvious that intelligent systems can dramatically improve the management of liver diseases. Big data made it possible to envisage transformative developments of the use of AI for diagnosing, predicting prognosis and treating liver diseases, but there is still a lot of work to do. If we want to achieve the 21^st century digital revolution, there is an urgent need for specific national and international rules, and to adhere to bioethical parameters when collecting data. Avoiding misleading results is essential for the effective use of AI. A crucial question is whether it is possible to sustain, technically and morally, the process of integration between man and machine. We present a systematic review on the applications of AI to hepatology, highlighting the current challenges and crucial issues related to the use of such technologies.

Current aspects of renal dysfunction after liver transplantation

The development of chronic kidney disease (CKD) after liver transplantation (LT) exerts a severe effect on the survival of patients. The widespread adoption of the model for end-stage liver disease score strongly impacted CKD incidence after the procedure, as several patients are transplanted with previously deteriorated renal function. Due to its multifactorial nature, encompassing pre-transplantation conditions, perioperative events, and nephrotoxic immunosuppressor therapies, the accurate identification of patients under risk of renal disease, and the implementation of preventive approaches, are extremely important. Methods for the evaluation of renal function in this setting range from formulas that estimate the glomerular filtration rate, to non-invasive markers, although no option has yet proved efficient in early detection of kidney injury. Considering the nephrotoxicity of calcineurin inhibitors (CNI) as a factor of utmost importance after LT, early nephroprotective strategies are highly recommended. They are based mainly on delaying the application of CNI during the immediate postoperative-period, reducing their dosage, and associating them with other less nephrotoxic drugs, such as mycophenolate mofetil and everolimus. This review provides a critical assessment of the causes of renal dysfunction after LT, the methods of its evaluation, and the interventions aimed at preserving renal function early and belatedly after LT.

Acute kidney injury and chronic kidney disease after liver transplant: A retrospective observational study

BACKGROUND AND RATIONALE

Chronic kidney disease remains an important risk factor for morbidity and mortality among LT recipients, but its exact incidence and risk factors are still unclear.

MATERIAL AND METHODS

We carried out a retrospective cohort study of consecutive adults who underwent liver transplant (January 2009-December 2018) and were followed (at least 6 months) at our institution. CKD was defined following the Kidney Disease: Improving Global Outcomes (KDIGO) 2012 Clinical Practice Guidelines. Long-term kidney function was classified into 4 groups: no CKD (eGFR, ≥60mL/min/1.73m²), mild CKD (eGFR, 30-59mL/min/1.73m²), severe CKD (eGFR, 15-29mL/min/1.73m²), and end-stage renal disease (ESRD).

RESULTS

We enrolled 410 patients followed for 53.2±32.6 months. 39 had CKD at baseline, and 95 developed de novo CKD over the observation period. There were 184 (44.9%) anti-HCV positive, 47 (11.5%) HBsAg positive, and 33 (8.1%) HBV/HDV positive recipients. Recipient risk factors for baseline CKD were advanced age (P=0.044), raised levels of serum uric acid (P<0.0001), and insulin dependent DM (P=0.0034). Early post-transplant AKI was common (n=95); logistic regression analysis found that baseline serum creatinine was an independent predictor of early post-LT AKI (P=0.0154). According to our Cox proportional hazards model, recipient risk factors for de novo CKD included aging (P<0.0001), early post-transplant AKI (P=0.007), and baseline serum creatinine (P=0.0002). At the end of follow-up, there were 116 LT recipients with CKD - 109 (93.9%) and 7 (6.1%) had stage 3 and advanced CKD, respectively. Only two of them are undergoing long-term dialysis.

CONCLUSION

The incidence of CKD was high in our cohort of LT recipients, but only a slight decline in kidney function over time was recorded. Prevention of post-transplant AKI will improve kidney function in the long run. We need more studies to analyze the function of kidneys among LT recipients over extended follow-ups and their impact on mortality.

Outcomes of Kidney Allograft and Recipient Survival After Liver Transplantation by Induction Type in the United States

There are several choices for induction immunosuppression in kidney-after-liver transplantation. We used the Scientific Registry of Transplant Recipients database. We assessed all kidney-after-liver transplant recipients in the United States between 1/1/2000 and 7/31/2017 to study kidney graft and patient outcomes by induction type. We only included patients discharged on tacrolimus and mycophenolate with or without steroids and had a negative crossmatch before kidney engraftment. We grouped recipients by kidney induction type into the following 3 groups: depletional (n = 550), nondepletional (n = 434), and no antibody induction (n = 144). We studied patient and kidney allograft survival using Cox proportional hazard regression, with transplant center included as a random effect. Models were adjusted for liver induction regimen, recipient and donor age, sex, human leukocyte antigen mismatches, payor type, living donor kidney transplantation, dialysis status, time from liver engraftment, hepatitis C virus status, and the presence of diabetes mellitus at time of kidney transplantation and transplantation year. The 6-month and 1-year rejection rates did not differ between groups. Compared with no induction, neither depletional nor nondepletional induction was associated with an improved recipient or graft survival in the multivariable models. Depletional induction at the time of liver transplantation was associated with worse patient survival after kidney transplantation (hazard ratio [HR], 1.7; 95% confidence interval [CI], 1.09-2.67; P = 0.02). Living donor kidney transplantation was associated with a 48.1% improved graft survival (HR, 0.52; 95% CI, 0.33-0.82; P = 0.00). In conclusion, in the settings of a negative cross-match and maintenance with tacrolimus and mycophenolate, induction use was not associated with a patient or graft survival benefit in kidney-after-liver transplantations.

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.

Kidney Failure after Liver Transplantation

One-third of patients with cirrhosis present kidney failure (AKI and CKD). It has multifactorial causes and a harmful effect on morbidity and mortality before and after liver transplantation. Kidney function does not improve in all patients after liver transplantation, and liver transplant recipients are at a high risk of developing chronic kidney disease. The causes of renal dysfunction can be divided into three groups: pre-operative, perioperative and post-operative factors. To date, there is no consensus on the modality to evaluate the risk of chronic kidney disease after liver transplantation, or for its prevention. In this narrative review, we describe the outcome of kidney function after liver transplantation, and the prognostic factors of chronic kidney disease in order to establish a risk categorization for each patient. Furthermore, we discuss therapeutic options to prevent kidney dysfunction in this context, and highlight the indications of combined liver–kidney transplantation.

Peri-operative risk factors of chronic kidney disease after liver transplantation

BACKGROUND

Chronic kidney disease (CKD) is a frequent long-term complication after liver transplantation (LT) and is associated with poor long-term survival. The aim of our study was to identify the risk factors of developing post-transplant CKD at 1 year, during the pre-operative, peri-operative, and post-LT phases.

METHODS

All consecutive patients who underwent primary LT between July 2013 and February 2018 were analyzed. To assess the impact of peri- and post-operative factors on renal function at 1 year we performed a propensity score matching on gender, age of the recipient, Model for End-Stage Liver Disease (MELD) score, etiology of the hepatic disease, and estimated Glomerular Filtration Rate (eGFR) at baseline.

RESULTS

Among the 245 patients who underwent LT, 215 had available data at one year (Y1), and 46% of them had CKD. Eighty-three patients in the CKD group and 83 in the normal renal function group were then matched. The median follow-up was 35 months (27-77). Patients with CKD at Y1 had a decreased 5-year survival compared to patients with normal renal function at one year: figures were 62% and 90%, respectively, p = 0.001. The independent predictors of CKD at Y1 were major complications (OR = 2.2, 95% CI [1.2-4.2]), p = 0.015, intensive care unit (ICU) stay > 5 days (OR = 2.2, 95% CI [1.3-5.1]), p = 0.046, ICU serum lactate level at 24 h ≥ 2.5 mmol/L (OR = 3.8 95% CI [1.1-8]), p = 0.034, need for post-LT renal replacement therapy (OR = 6.4 95% CI [1.4-25]), and MELD score ≥ 20 (OR = 2.1 95% CI [1.1-3.9]), p = 0.019.

CONCLUSIONS

The peri-operative period has a major impact on CKD incidence. Early recognition of patients at high risk of CKD may be critical for implementation of nephroprotective measures.

Renal Outcomes After Simultaneous Liver-Kidney Transplantation: Results from the US Multicenter Simultaneous Liver-Kidney Transplantation Consortium

Simultaneous liver-kidney transplantation (SLKT) is increasingly common in the United States. However, little is known about the renal-related outcomes following SLKT, which are essential to maximize the health of these allografts. We examined the factors impacting renal function following SLKT. This is an observational multicenter cohort study from the US Multicenter SLKT Consortium consisting of recipients of SLKT aged ≥18 years of transplantations performed between February 2002 and June 2017 at 6 large US centers in 6 different United Network for Organ Sharing regions. The primary outcome was incident post-SLKT stage 4-5 chronic kidney disease (CKD) defined as <30 mL/minute/1.73 m² or listing for kidney transplant. The median age of the recipients (n = 570) was 58 years (interquartile range, 51-64 years), and 37% were women, 76% were White, 33% had hepatitis C virus infection, 20% had nonalcoholic steatohepatitis (NASH), and 23% had alcohol-related liver disease; 68% developed ≥ stage 3 CKD at the end of follow-up. The 1-year, 3-year, and 5-year incidence rates of post-SLKT stage 4-5 CKD were 10%, 12%, and 16%, respectively. Pre-SLKT diabetes mellitus (hazard ratio [HR], 1.45; 95% CI, 1.00-2.15), NASH (HR, 1.58; 95% CI, 1.01-2.45), and delayed kidney graft function (HR, 1.72; 95% CI, 1.10-2.71) were the recipient factors independently associated with high risk, whereas the use of tacrolimus (HR, 0.44; 95% CI, 0.22-0.89) reduced the risk. Women (β = -6.22 ± 2.16 mL/minute/1.73 m² ; P = 0.004), NASH (β = -7.27 ± 3.27 mL/minute/1.73 m² ; P = 0.027), and delayed kidney graft function (β = -7.25 ± 2.26 mL/minute/1.73 m² ; P = 0.007) were independently associated with low estimated glomerular filtration rate at last follow-up. Stage 4-5 CKD is common after SLKT. There remains an unmet need for personalized renal protective strategies, specifically stratified by sex, diabetes mellitus, and liver disease, to preserve renal function among SLKT recipients.

Black Race Is Associated With Higher Rates of Early-Onset End-Stage Renal Disease and Increased Mortality Following Liver Transplantation

Black race is a risk factor for end-stage renal disease (ESRD). Racial disparities in the risks of early and long-term renal complications after liver transplantation (LT) have not been systematically studied. This study evaluated racial differences in the natural history of acute and chronic renal insufficiency after LT. This was a retrospective single-center cohort study of 763 non-Hispanic White and 181 Black LT recipients between 2008 and 2017. Black race was investigated as an independent predictor of the following outcomes: (1) receipt and duration of early post-LT hemodialysis and (2) time to post-LT ESRD. The interaction of race and post-LT ESRD on survival was also studied. Black recipients had higher rates of pre-LT hypertension (P < 0.001), but diabetes mellitus and renal function before LT were not different by race (all P > 0.05). Overall, 15.2% of patients required early hemodialysis immediately after LT with no difference by race (covariate-adjusted odds ratio, 0.89; P = 0.71). Early dialysis discontinuation was lower among Black recipients (covariate-adjusted hazard ratio [aHR], 0.47; P = 0.02), whereas their rate of post-LT ESRD was higher (aHR, 1.91; P = 0.005). Post-LT survival after ESRD was markedly worse for Black (aHR, 11.18; P < 0.001) versus White recipients (aHR, 5.83; P < 0.001; interaction P = 0.08). Although Black and White LT recipients had comparable pretransplant renal function, post-LT renal outcomes differed considerably, and the impact of ESRD on post-LT survival was greater for Black recipients. This study highlights the need for an individualized approach to post-LT management to improve outcomes for all patients.

Dynamics of glucose metabolism after liver transplantation: Prediabetes as a window of opportunity for patient survival and long-term kidney function

Posttransplantation diabetes mellitus (PTDM) is a relevant complication following liver transplantation with profound impact on morbidity and mortality. To date, little is known about the evolution and dynamics of glucose metabolism and the impact of prediabetes in long-term follow-up. To address this issue, all consecutive adult liver transplant recipients (n=429) from a European university hospital transplant center between 2007 and 2017 were analyzed retrospectively. In patients without pre-existing diabetes (n=327), we conducted a longitudinal characterization of glucose metabolism. Median follow-up was 37 [9-64, IQR] months. Median prevalence of prediabetes was 39 [37-39]% and of PTDM 21 [17-22]%. Throughout follow-up, intra-individual glucose regulation of patients was highly variable, continuously fluctuating between different states of glucose metabolism (normal glucose tolerance, prediabetes, PTDM). Whereas overall survival and long-term kidney function of patients with PTDM were significantly lower than that of patients with normal glucose metabolism, prediabetes was not associated with adverse outcome. This study provides new insight into the dynamics and impact of glucose metabolism after liver transplantation. Unlike PTDM, prediabetes is not associated with adverse outcome, providing a window of opportunity for targeted intervention. The results underline the need for constant screening and intervention in post-transplant care of liver allograft recipients.

Acute kidney injury and chronic kidney disease after liver transplant: A retrospective observational study

BACKGROUND AND RATIONALE

Chronic kidney disease remains an important risk factor for morbidity and mortality among LT recipients, but its exact incidence and risk factors are still unclear.

MATERIAL AND METHODS

We carried out a retrospective cohort study of consecutive adults who underwent liver transplant (January 2009-December 2018) and were followed (at least 6 months) at our institution. CKD was defined following the Kidney Disease: Improving Global Outcomes (KDIGO) 2012 Clinical Practice Guidelines. Long-term kidney function was classified into 4 groups: no CKD (eGFR, ≥60mL/min/1.73m2), mild CKD (eGFR, 30-59mL/min/1.73m2), severe CKD (eGFR, 15-29mL/min/1.73m2), and end-stage renal disease (ESRD).

RESULTS

We enrolled 410 patients followed for 53.2±32.6 months. 39 had CKD at baseline, and 95 developed de novo CKD over the observation period. There were 184 (44.9%) anti-HCV positive, 47 (11.5%) HBsAg positive, and 33 (8.1%) HBV/HDV positive recipients. Recipient risk factors for baseline CKD were advanced age (P=0.044), raised levels of serum uric acid (P<0.0001), and insulin dependent DM (P=0.0034). Early post-transplant AKI was common (n=95); logistic regression analysis found that baseline serum creatinine was an independent predictor of early post-LT AKI (P=0.0154). According to our Cox proportional hazards model, recipient risk factors for de novo CKD included aging (P<0.0001), early post-transplant AKI (P=0.007), and baseline serum creatinine (P=0.0002). At the end of follow-up, there were 116 LT recipients with CKD - 109 (93.9%) and 7 (6.1%) had stage 3 and advanced CKD, respectively. Only two of them are undergoing long-term dialysis.

CONCLUSION

The incidence of CKD was high in our cohort of LT recipients, but only a slight decline in kidney function over time was recorded. Prevention of post-transplant AKI will improve kidney function in the long run. We need more studies to analyze the function of kidneys among LT recipients over extended follow-ups and their impact on mortality.

COVID-19 and liver disease: mechanistic and clinical perspectives

Our understanding of the hepatic consequences of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and its resultant coronavirus disease 2019 (COVID-19) has evolved rapidly since the onset of the pandemic. In this Review, we discuss the hepatotropism of SARS-CoV-2, including the differential expression of viral receptors on liver cell types, and we describe the liver histology features present in patients with COVID-19. We also provide an overview of the pattern and relevance of abnormal liver biochemistry during COVID-19 and present the possible underlying direct and indirect mechanisms for liver injury. Furthermore, large international cohorts have been able to characterize the disease course of COVID-19 in patients with pre-existing chronic liver disease. Patients with cirrhosis have particularly high rates of hepatic decompensation and death following SARS-CoV-2 infection and we outline hypotheses to explain these findings, including the possible role of cirrhosis-associated immune dysfunction. This finding contrasts with outcome data in pharmacologically immunosuppressed patients after liver transplantation who seem to have comparatively better outcomes from COVID-19 than those with advanced liver disease. Finally, we discuss the approach to SARS-CoV-2 vaccination in patients with cirrhosis and after liver transplantation and predict how changes in social behaviours and clinical care pathways during the pandemic might lead to increased liver disease incidence and severity.

COVID-19 Outcomes Among Solid Organ Transplant Recipients: A Case-control Study

BACKGROUND

Solid organ transplant (SOT) recipients are considered to be "vulnerable" to COVID-19 infection due to immunosuppression. To date, there are no studies that compared the disease severity of COVID-19 in SOT recipients with nontransplant patients.

METHODS

In this case-control study, we compared the outcomes of COVID-19 between SOT recipients and their matched nontransplant controls. The cases were all adult SOT recipients (N = 41) from our academic health center who were diagnosed with COVID-19 between March 10, 2020 and May 15, 2020 using positive reverse transcriptase polymerase chain reaction for SARS-CoV2. The controls (N = 121) were matched on age (±5 y), race, and admission status (hospital or outpatient). The primary outcome was death and secondary outcomes were severe disease, intubation and renal replacement therapy (RRT).

RESULTS

Median age of SOT recipients (9 heart, 3 lung, 16 kidney, 8 liver, and 5 dual organ) was 60 y, 80% were male and 67% were Black. Severe disease adjusted risk of death was similar in both the groups (hazard ratio = 0.84 [0.32-2.20]). Severity of COVID-19 and intubation were similar, but the RRT use was higher in SOT (odds ratio = 5.32 [1.26, 22.42]) compared to non-SOT COVID-19 patients. Among SOT recipients, COVID-19-related treatment with hydroxychloroquine (HCQ) was associated with 10-fold higher hazard of death compared to without HCQ (hazard ratio = 10.62 [1.24-91.09]).

CONCLUSIONS

Although African Americans constituted one-tenth of all SOT in our center, they represented two-thirds of COVID-19 cases. Despite high RRT use in SOT recipients, the severe disease and short-term death were similar in both groups. HCQ for the treatment of COVID-19 among SOT recipients was associated with high mortality and therefore, its role as a treatment modality requires further scrutiny.

Long-term Management of the Adult Liver Transplantation Recipients

The survival of liver transplantation (LT) recipients has been improved remarkably in short-term. The major causes of mortality in long-term include nonimmunological causes such as cardiovascular, de novo malignancy, chronic kidney disease, and recurrence of primary disease. Rejection-related mortality is rare in the long-term after LT. We discuss nonrejection causes of long-term morbidity/mortality, risk factors, and management strategies in LT recipients. In addition, we discuss osteoporosis, contraception, and pregnancy in LT recipients.

Medical care of liver transplant patients

INTRODUCTION

Liver transplantation is a life-changing event for patients and survival following transplantation has improved significantly since the first transplantation in 1967. Following liver transplantation, patients face a unique set of healthcare management decisions including transplantation-specific complications, recurrence of primary liver disease, as well as metabolic and malignancy concerns related to immunosuppression. As more patients with liver disease receive transplantation and live longer, understanding and managing these patients will require not only transplant specialist but also local subspecialist and primary care physicians.

AREAS COVERED

This review covers common issues related to the management of patients following liver transplantation including immunosuppression, liver allograft dysfunction, metabolic complications, as well as routine health maintenance such as immunizations and cancer screening.

EXPERT OPINION

Optimizing medical care for patients following liver transplant will benefit from ensuring all providers, not just transplant specialist, have a basic understanding of the common issues encountered in the post-transplant patient. This review provides an overview of common healthcare concerns and management options for patients following liver transplantation.

Role of Terlipressin and Albumin for Hepatorenal Syndrome in Liver Transplantation

Hepatorenal syndrome (HRS) is one of the most ominous complications of portal hypertension in patients with decompensated cirrhosis and ascites. It is associated with very high mortality on the wait list. Liver transplantation (LT) is the most successful therapeutic option for patients with HRS. However, not all the LT candidates with HRS are able to receive a deceased donor allograft in a timely manner because it is a scarce resource and patients may need alternative best supportive treatment with systemic splanchnic vasoconstrictors and albumin as a bridge to transplant. The combination of terlipressin and albumin is efficacious in the reversal of HRS and is used worldwide. More recently, the multicenter, randomized, placebo-controlled double-blind study to confirm efficacy and safety of terlipressin in subjects with hepatorenal syndrome type 1 (the CONFIRM study) trial demonstrated the efficacy of terlipressin and albumin in the reversal of HRS in a North American cohort. The aim of this article is to review the role of terlipressin and albumin in LT candidates with HRS in the United States.

Prediction of Liver Prognosis from Pre-Transplant Renal Function Adjusted by Diuretics and Urinary Abnormalities in Adult-to-Adult Living Donor Liver Transplantation

BACKGROUND Renal function is strongly associated with patient survival after liver transplantation. However, the estimated glomerular filtration rate (eGFR) after liver transplantation changes, especially in patients who receive diuretics or have urinary abnormalities. We aimed to elucidate how adjusting for these factors affecting eGFR predicted liver graft prognosis. MATERIAL AND METHODS This retrospective study included patients who underwent adult-to-adult living donor liver transplantation (LDLT) between 2000 and 2017. The factors affecting eGFR were assessed, and the association between eGFR and prognosis was investigated using Cox regression models after adjusting for factors affecting renal function. RESULTS We enrolled 244 patients. The median observation period was 4.6 years, and 88 patients reached graft loss or death with a functioning graft. One year after transplantation, 193 patients were living, and one-third of these showed improved eGFR; most of the patients with improved eGFR had taken diuretics before transplantation. A Cox regression model adjusted for the classical risk factors showed that donor age (P<0.001) and lower eGFR (P=0.02) were the independent risk factors associated with poor prognosis. After adjusting for diuretics and urinary abnormalities, eGFR was more strongly associated with liver graft prognosis (P=0.003). CONCLUSIONS Pre-transplant eGFR was associated with prognosis following LDLT and had a stronger effect on prognosis after adjusting for factors affecting eGFR.

Delayed Implantation of Pumped Kidneys Decreases Renal Allograft Futility in Combined Liver-Kidney Transplantation

BACKGROUND

Combined liver-kidney transplantation (CLKT) improves survival for liver transplant recipients with renal dysfunction; however, the tenuous perioperative hemodynamic and metabolic milieu in high-acuity CLKT recipients increases delayed graft function and kidney allograft failure. We sought to analyze whether delayed KT through pumping would improve kidney outcomes following CLKT.

METHODS

A retrospective analysis (University of California Los Angeles [n = 145], Houston Methodist Hospital [n = 79]) was performed in all adults receiving CLKT at 2 high-volume transplant centers from February 2004 to January 2017, and recipients were analyzed for patient and allograft survival as well as renal outcomes following CLKT.

RESULTS

A total of 63 patients (28.1%) underwent delayed implantation of pumped kidneys during CLKT (dCLKT) and 161 patients (71.9%) received early implantation of nonpumped kidneys during CLKT (eCLKT). Most recipients were high-acuity with median biologic model of end-stage liver disease (MELD) score of, 35 for dCLKT and 34 for eCLKT (P = ns). Pretransplant, dCLKT had longer intensive care unit stay, were more often intubated, and had greater vasopressor use. Despite this, dCLKT exhibited improved 1-, 3-, and 5-year patient and kidney survival (P = 0.02) and decreased length of stay (P = 0.001), kidney allograft failure (P = 0.012), and dialysis duration (P = 0.031). This reduced kidney allograft futility (death or continued need for hemodialysis within 3 mo posttransplant) for dCLKT (6.3%) compared with eCLKT (19.9%) (P = 0.013).

CONCLUSIONS

Delayed implantation of pumped kidneys is associated with improved patient and renal allograft survival and decreased hospital length of stay despite longer kidney cold ischemia. These data should inform the ethical debate as to the futility of performing CLKT in high-acuity recipients.

Area Under Trough Concentrations of Tacrolimus as a Predictor of Progressive Renal Impairment After Liver Transplantation

BACKGROUND

Tacrolimus minimization is usually restricted to patients with pretransplant renal impairment, and this strategy could result into worse renal outcomes after liver transplantation (LT).

METHODS

A consecutive cohort of 455 LT patients receiving tacrolimus-based immunosuppression was studied (2008-2013). Cumulative exposure to tacrolimus was calculated as the area under curve of trough concentrations (AUCtc). Patients were stratified as tacrolimus minimization, conventional, or high exposure, according to the thresholds based in the COMMIT consensus. Estimated glomerular filtration rates (eGFR) were assessed by the Modification of Diet in Renal Disease formula (MDRD-4) up to 5 years after LT.

RESULTS

Seventy patients (15.4%) had pretransplant eGFR < 60 mL/min, which was associated with increased mortality rates, particularly within the first 5 years post-LT (31.4% versus 17.5%; Breslow P = 0.010). After LT, there was an abrupt eGFR decline within the first 3 months (median 18.6 mL/min; P < 0.001), further decreasing up to 12 months (additional 3 mL/min), without any improvement thereafter. According to AUCtc, 33.7% of patients received tacrolimus minimization, 44.8% conventional exposure, and 21.5% high exposure. Conventional/high exposure to tacrolimus resulted in a more pronounced eGFR decline within the first 3 months when compared with minimization (23.3 mL/min versus 9.5 mL/min; P < 0.001). This gap was even higher in patients with initially preserved renal function. Tacrolimus AUCtc was an independent predictor of eGFR decline within the first 3 months after controlling for potential confounders.

CONCLUSIONS

AUCtc is a surrogate of cumulative exposure to tacrolimus and may be helpful for routine dose adjustments. Tacrolimus minimization should be universally attempted after LT to preserve renal function.

Racial/Ethnic Disparities in Access and Outcomes of Simultaneous Liver-Kidney Transplant Among Liver Transplant Candidates With Renal Dysfunction in the United States

BACKGROUND

Since the Model for End-stage Liver Disease (MELD) allocation system was implemented, the proportion of simultaneous liver-kidney transplantation (SLKT) has increased significantly. However, whether racial/ethnic disparities exist in access to SLKT and post-SLKT survival remains understudied.

METHODS

A retrospective cohort of patients aged ≥18 years with renal dysfunction on the liver transplant (LT) waiting list was obtained from Organ Procurement and Transplantation Network. Renal dysfunction was defined as estimated glomerular filtration rate <60 mL/min/1.73 m at listing for LT. Multilevel time-to-competing-events regression adjusting for center effect was used to examine the likelihood of receiving SLKT. Inverse probability of treatment weighted survival analyses were used to analyze posttransplant mortality outcomes.

RESULTS

For patients with renal dysfunction at listing for LT, not listed for simultaneous kidney transplant, non-Hispanic black (NHB) and Hispanic patients were more likely to receive SLKT than non-Hispanic white (NHW) patients (NHB: multivariable-adjusted hazard ratio [aHR] 2.57; 95% confidence interval [CI], 1.42-4.65; Hispanic: aHR, 2.03; 95% CI, 1.14-3.60). For post-SLKT outcomes, compared to NHW patients, NHB patients had a lower mortality risk before 24 months (aHR, 0.80; 95% CI, 0.65-0.97) but had a higher mortality risk (aHR, 2.00; 95% CI, 1.59-2.55) afterward; in contrast, Hispanic patients had a lower overall mortality risk than NHW patients (aHR, 0.61; 95% CI, 0.51-0.74).

CONCLUSIONS

In the MELD era, racial/ethnic differences exist in access and survival of SLKT for patients with renal dysfunction at listing for LT. Future studies are warranted to examine whether these differences remain in the post-SLK allocation policy era.

The proportion of Model for End-stage Liver Disease Sodium score attributable to creatinine independently predicts post-transplant survival and renal complications

The post-transplant outcomes of patients with Model for End-stage Liver Disease (MELD) score primarily driven by renal dysfunction are poorly understood. This was a retrospective cohort study of liver transplant (LT) alone recipients between 2005 and 2017 using the United Network for Organ Sharing (UNOS) database. The proportion of MELD Sodium score attributable to creatinine ("KidneyMELD") was calculated: (9.57 × ln (creatinine) × 100)/(MELD-Na - 6.43). The association of KidneyMELD with (a) all-cause mortality and (b) estimated glomerular filtration rate ≤30 mL/min/1.73² at 1-year post-LT were evaluated. Recipients with KidneyMELD ≥50% had a 52% higher risk of post-LT mortality (adjusted hazard ratio 1.52 vs KidneyMELD 0%, 95% CI: 1.36-1.69; P < .001). This risk was significantly greater for older patients, particularly when >50 years at LT (interaction P < .001). KidneyMELD ≥50% was also associated with an 11-fold increase in the odds of advanced renal dysfunction at 1-year post-LT (adjusted odds ratio 11.53 vs KidneyMELD 0%; 95% CI 8.9-14.93; P < .001). Recipients prioritized for LT primarily on the basis of renal dysfunction have marked post-LT mortality and morbidity independent of MELD Sodium score. The implications of these results in the context of the new UNOS "safety net" kidney transplant policy require further study.

Renal Outcomes of Liver Transplantation Recipients Receiving Standard Immunosuppression and Early Renal Sparing Immunosuppression: A Retrospective Single Center Study

New-onset stage 4-5 chronic kidney disease (CKD) after liver transplantation (LT) is associated with high morbidity, mortality, and economic burden. In 2010, we instituted an early renal sparing immunosuppression (RSI) protocol for LT recipients with severe renal dysfunction (pre-LT dialysis/estimated glomerular filtration rate (eGFR)<30mL/min/1.73 m2 or post-LT acute kidney injury) consisting of 2 doses of basiliximab for induction and delaying tacrolimus to post-LT day 4-7. We examined the effect of early RSI on post-LT renal outcomes.

METHODS

Data on all adults who had LT between January 1, 2010, and December 12, 2014 were collected. We calculated the renal risk index (RRI) score for each LT recipient (https://rri.med.umich.edu). Primary outcome was new-onset post-LT stage 4-5 CKD.

RESULTS

Of 214 LT recipients, 121 (57%) received early RSI and 93 (43%) received standard immunosuppression. Cumulative incidence of new-onset stage 4-5 CKD was higher in early RSI compared with standard immunosuppression (P = 0.03). Female sex and RRI score were the significant risk factors for development of post-LT stage CKD in the entire study cohort as well as the LT recipients with RRI ≥ sixth decile (high-risk group).

CONCLUSIONS

Delaying tacrolimus initiation combined with basiliximab induction did not have a durable effect on long-term renal outcomes in high-risk LT recipients. Further studies are needed to identify the effective strategies to preserve renal function by targeting patients at high risk for CKD progression.

Novel educational and goal-setting tool to improve knowledge of chronic kidney disease among liver transplant recipients: A pilot study

Introduction

Liver transplant (LT) recipients have limited understanding of post-transplant chronic kidney disease (CKD) despite an excellent pre-existing framework of transplant care. This pilot study examined the efficacy and feasibility of a tailored educational and goal-setting tool in improving CKD knowledge among LT recipients with early-stage CKD.

Methods

In this prospective cohort study, we administered the CKD educational and goal-setting tool to 81 LT recipients between 7/1/2016 and 12/31/2017. We excluded patients with simultaneous liver-kidney transplantation, eGFR<30 ml/min, non-English speaking, on hemodialysis or listed for kidney transplantation. The pre- and post-education knowledge scores were compared using a paired t-test. Linear regression was used to assess the independent predictors of change in knowledge score.

Results

Mean age was 56.3 years, 69.1% were males, 85.2% were Caucasians and mean eGFR was 61.2 ± 20.0 ml/min. The CKD educational and goal-setting tool improved the CKD knowledge scores among LT recipients (pre: 71.8 ± 16.6%, post: 83.3 ± 10.4%; p<0.001). In an adjusted model (r² = 0.75), those with lower pre-education knowledge scores had the most improvement in their post-education knowledge scores (β = -83.2; p<0.001). Two-thirds stated their most important self-management goal and reported motivation to follow this goal. Time spent for the CKD education was approximately 15 minutes.

Conclusions

A simple LT-specific patient educational and goal-setting tool effectively improved CKD knowledge. Implementation of this tailored intervention will improve CKD awareness and may promote goal-setting in the target population.

Long-term impact of dialysis-requiring AKI during the perioperative period of liver transplantation on postdischarge outcomes

BACKGROUND

Patients undergoing liver transplantation (LT) are prone to dialysis-requiring acute kidney injury (AKI-D). However, long-term prognoses among them need further investigation, as overall survival after LT is improving.

METHODS

A nationwide, population-based cohort study was conducted using the data of Korean National Health Insurance System between 2006 and 2015. The patients who received dialysis during the perioperative period of LT were in the AKI-D group, and the control group included those who did not undergo dialysis.

RESULTS

Among the 6879 patients who underwent LT, 968 were in the AKI-D group. All-cause mortality [adjusted hazard ratio (HR): 1.52 (1.26-1.83), P < 0.001], end-stage renal disease (ESRD) progression [adjusted HR: 2.93 (2.34-3.66), P < 0.001], and ICU readmission [adjusted HR: 1.70 (1.44-2.01), P < 0.001] within and after 90 days from discharge were increased in the AKI-D group. When analyzed among those who recovered from dialysis at discharge, overall outcomes were similar to those of the AKI-D group, except the long-term mortality.

CONCLUSIONS

AKI-D during the perioperative period of LT was associated with worse mortality, ESRD progression, and ICU readmission risk. The results of renal-recovered patients could indicate clinicians that achievement of dialysis independence is important to gain favorable long-term postdischarge survival.

Chronic Kidney Disease After Liver Transplantation: Impact of Extended Criteria Grafts

The use of extended criteria donor (ECD) grafts has been associated with acute kidney injury (AKI) after liver transplantation. However, the relation between graft quality and development of chronic kidney disease (CKD) remains unknown. Therefore, the aim of this study was to analyze the impact of ECD grafts for CKD after liver transplantation. All patients (2007-2015) transplanted for end-stage liver disease at our center were assessed. Longterm kidney function was divided into 4 groups: no CKD (estimated glomerular filtration rate [eGFR], ≥60 mL/minute/1.73 m² ), mild CKD (eGFR, 30-59 mL/minute/1.73 m² ), severe CKD (eGFR, 15-29 mL/minute/1.73 m² ), and end-stage renal disease (ESRD). Marginal donation after brain death (DBD) grafts (donor age, >70 years; body mass index, >35 kg/m² ; cold storage, >12 hours) and donation after circulatory death (DCD) grafts were considered ECD grafts. Overall, 926 patients were included, and 43% received an ECD graft (15% marginal DBD; 28% DCD). After 5 years, 35% developed CKD; severe CKD and ESRD occurred in only 2% and 1%, respectively. CKD rates were comparable for all 3 graft groups (standard group, 36%; marginal DBD group, 29%; DCD group, 35%; standard versus marginal DBD groups, P = 0.16; standard versus DCD group, P = 0.80). None of the ECD criteria were identified as independent risk factors in a Cox regression model for CKD. Risk factors included recipient age, female sex, and preoperative kidney function. Furthermore, recipients who had severe acute kidney injury (AKI; Kidney Disease: Improving Global Outcomes stages 2 and 3) had a 1.8-fold increased risk for CKD. Longterm kidney function of recipients with severe AKI depended on the recovery of kidney function in the first postoperative week. In conclusion, there is no direct relation between the use of ECD grafts and CKD after liver transplantation. However, caution should be taken in recipients who experience severe AKI, regardless of graft type.

From a Philosophical Framework to a Valid Prognostic Staging System of the New "Comprehensive Assessment" for Transplantable Hepatocellular Carcinoma

The comprehensive assessment of the transplantable tumor (TT) proposed and included in the last Italian consensus meeting still deserve validation. All consecutive patients with hepatocellular carcinoma (HCC) listed for liver transplant (LT) between January 2005 and December 2015 were post-hoc classified by the tumor/patient stage as assessed at the last re-staging-time (ReS-time) before LT as follow: high-risk-class (HRC) = stages TT_DR, TT_PR; intermediate-risk-class (IRC) = TT0_NT, TT_FR, TT_UT; low-risk-class (LRC) = TT1, TT0_L, TT0_C. Of 376 candidates, 330 received LT and 46 dropped-out. Transplanted patients were: HRC for 159 (48.2%); IRC for 63 (19.0%); LRC for 108 (32.7%). Cumulative incidence function (CIF) of tumor recurrence after LT was 21%, 12%, and 8% at 5-years and 27%, 15%, and 12% at 10-years respectively for HRC, IRC, and LRC (P = 0.011). IRC patients had significantly lower CIF of recurrence after LT if transplanted >2-months from ReS-time (28% vs. 3% for <2 and >2 months, P = 0.031). HRC patients had significantly lower CIF of recurrence after-LT if transplanted <2 months from the ReS-time (10% vs. 33% for <2 and >2 months, P = 0.006). The proposed TT staging system can adequately describe the post-LT recurrence, especially in the LRC and HRC patients. The intermediate-risk-class needs to be better defined and further studies on its ability in defining intention-to-treat survival (ITT) and drop-out are required.

Very Early Introduction of Everolimus in De Novo Liver Transplantation: Results of a Multicenter, Prospective, Randomized Trial

Early everolimus (EVR) introduction and tacrolimus (TAC) minimization after liver transplantation may represent a novel immunosuppressant approach. This phase 2, multicenter, randomized, open-label trial evaluated the safety and efficacy of early EVR initiation. Patients treated with corticosteroids, TAC, and basiliximab were randomized (2:1) to receive EVR (1.5 mg twice daily) on day 8 and to gradually minimize or withdraw TAC when EVR was stable at >5 ng/mL or to continue TAC at 6-12 ng/mL. The primary endpoint was the proportion of treated biopsy-proven acute rejection (tBPAR)-free patients at 3 months after transplant. As secondary endpoints, composite tBPAR plus graft/patient loss rate, renal function, TAC discontinuation rate, and adverse events were assessed. A total of 93 patients were treated with EVR, and 47 were controls. After 3 months from transplantation, 87.1% of patients with EVR and 95.7% of controls were tBPAR-free (P = 0.09); composite endpoint-free patients with EVR were 85% (versus 94%; P = 0.15). Also at 3 months, 37.6% patients were in monotherapy with EVR, and the tBPAR rate was 11.4%. Estimated glomerular filtration rate was significantly higher with EVR, as early as 2 weeks after randomization. In the study group, higher rates of dyslipidemia (15% versus 6.4%), wound complication (18.32% versus 0%), and incisional hernia (25.8% versus 6.4%) were observed, whereas neurological disorders were more frequent in the control group (13.9% versus 31.9%; P < 0.05). In conclusion, an early EVR introduction and TAC minimization may represent a suitable approach when immediate preservation of renal function is crucial.

Comparing Simultaneous Liver-Kidney Transplant Strategies: A Modified Cost-Effectiveness Analysis

BACKGROUND

The proportion of patients with kidney failure at time of liver transplantation is at a historic high in the United States. The optimal timing of kidney transplantation with respect to the liver transplant is unknown.

METHODS

We used a modified cost-effectiveness analysis to compare 4 strategies: the old system ("pre-OPTN"), the new Organ Procurement Transplant Network (OPTN) system since August 10, 2017 ("OPTN"), and 2 strategies which restrict simultaneous liver-kidney transplants ("safety net" and "stringent"). We measured "cost" by deployment of deceased donor kidneys (DDKs) to liver transplant recipients and effectiveness by life years (LYs) and quality-adjusted life years (QALYs) in liver transplant recipients. We validated our model against Scientific Registry for Transplant Recipients data.

RESULTS

The OPTN, safety net and stringent strategies were on the efficiency frontier. By rank order, OPTN > safety net > stringent strategy in terms of LY, QALY, and DDK deployment. The pre-OPTN system was dominated, or outperformed, by all alternative strategies. The incremental LY per DDK between the strategies ranged from 1.30 to 1.85. The incremental QALY per DDK ranged from 1.11 to 2.03.

CONCLUSIONS

These estimates quantify the "organ"-effectiveness of various kidney allocation strategies for liver transplant candidates. The OPTN system will likely deliver better liver transplant outcomes at the expense of more frequent deployment of DDKs to liver transplant recipients.

Chronic kidney disease in liver transplantation: Evaluation of kidney function

Chronic kidney disease is one of the main comorbidities affecting liver transplant recipients. Most of those patients have some degree of acute or chronic kidney dysfunction at the time of transplantation, moreover they can also develop de novo chronic kidney disease once transplanted. An important increase in the incidence of chronic kidney disease in the «MELD era» has been observed. This phenomenon has partially been attributed to the weight that kidney function carries for organ allocation. In addition, the generalized use of calcineurin inhibitors has also been a contributing factor. It is of the utmost importance for us to be familiar with the current methods for evaluating kidney function before and after a liver transplantation. The two main biomarkers available today for that purpose are serum creatinine and cystatin C. Several equations have been derived from those biomarkers and have been tested in that context with mixed results, due to their biologic variability and the lack of standardization in their measurement. The gold standard continues to be the direct determination of the glomerular filtration rate through different methods; however, that is only done for research purposes. It is also essential to know the current classification of acute kidney injury and chronic kidney disease in order to make early diagnosis. The present review focuses on the recognition, diagnosis, and classification of chronic kidney disease and acute kidney injury in liver transplantation recipients.

Piggyback or Cava Replacement: Which Implantation Technique Protects Liver Recipients From Acute Kidney Injury and Complications?

The cava-preserving piggyback (PB) technique requires only partial cava clamping during the anhepatic phase in liver transplantation (LT) and, therefore, maintains venous return and may hemodynamically stabilize the recipient. Hence, it is an ongoing debate whether PB implantation is more protective from acute kidney injury (AKI) after LT when compared with a classic cava replacement (CR) technique. The aim of this study was to assess the rate of AKI and other complications after LT comparing both transplant techniques without the use of venovenous bypass. We retrospectively analyzed the adult donation after brain death LT cohort between 2008 and 2016 at our center. Liver and kidney function and general outcomes including complications were assessed. Overall 378 transplantations were analyzed, of which 177 (46.8%) were performed as PB and 201 (53.2%) as CR technique. AKI occurred equally often in both groups. Transient renal replacement therapy was required in 22.6% and 22.4% comparing the PB and CR techniques (P = 0.81). Further outcome parameters including the complication rate were similar in both cohorts. Five-year graft and patient survival were comparable between the groups with 81% and 85%, respectively (P = 0.48; P = 0.58). In conclusion, both liver implantation techniques are equal in terms of kidney function and overall complications following LT.