Predisposing factors of diminished survival in simultaneous liver/kidney transplantation

Dual organ transplantation: Pancreas and Liver in the kidney axis

PURPOSE OF REVIEW

This article explores the benefits and challenges of dual organ transplants.

RECENT FINDINGS

Simultaneous liver-kidney transplant has become a valuable option for patients with both liver and kidney failure, especially since the introduction of clearer eligibility guidelines in 2017. When done for the appropriate candidate, it can significantly improve survival and quality of life. Similarly, simultaneous pancreas-kidney transplantation provides significant advantages for patients with diabetes-related kidney failure by addressing both glycemic control and kidney function, with significant improvement in diabetes associated complications and survival.

SUMMARY

While these procedures are complex, they offer promising solutions for managing difficult multiorgan conditions. Ongoing research and personalized patient care will be key to maximizing their benefits.

Simultaneous liver-kidney transplantation: future perspective

BACKGROUND

The aims of this narrative review were (i) to describe the current indications of SLKT, (ii) to report evolution of SLKT activity, (iii) to report the outcomes of SLKT, (iv) to explain the immune-protective effect of liver transplant on kidney transplant, (v) to explain the interest of delay kidney transplantation, using hypothermic machine perfusion (HMP), (vi) to report kidney after liver transplantation (KALT) indications and (vii) to describe the value of the increase in the use of extended criteria donors (ECD) and particular controlled donation after circulatory death (cDCD) transplant, thanks to the development of new organ preservation strategies.

METHOD

Electronic databases were screened using the keywords "Simultaneous", "Combined", "kidney transplantation" and "liver transplantation". The methodological and clinical heterogeneity of the included studies meant that meta-analysis was inappropriate.

RESULTS

 A total of 1,917 publications were identified in the literature search. Two reviewers screened all study abstracts independently and 1,107 of these were excluded. Thus, a total of 79 full text articles were assessed for eligibility. Of these, 21 were excluded. In total, 58 studies were included in this systematic review.

CONCLUSIONS

 Simultaneous liver-kidney transplantation has made a significant contribution for patients with dual-organ disease. The optimization of indication and selection of SLKT patients will reduce futile transplantation. Moreover, increasing the use of transplants from extended criteria donors, in particular cDCD, should be encouraged, thanks to the development of new modalities of organ preservation.

Immunology of simultaneous liver and kidney transplants with identification and prevention of rejection

Simultaneous liver and kidney (SLK) transplantation is considered the best treatment modality among selected patients with both chronic kidney disease (CKD) and end-stage liver disease (ESLD). Since the first SLK transplant in 1983, the number of SLK transplants has increased worldwide, and particularly in the United States since the implementation of the MELD system in 2002. SLK transplants are considered a relatively low immunological risk procedure evidenced by multiple studies displaying the immunomodulatory properties of the liver on the immune system of SLK recipients. SLK recipients demonstrate lower rates of both cellular and antibody-mediated rejection on the kidney allograft when compared to kidney transplant-alone recipients. Therefore, SLK transplants in the setting of preformed donor-specific HLA antibodies (DSA) are a common practice, at many centers. Acceptance and transplantation of SLKs are based solely on ABO compatibility without much consideration of crossmatch results or DSA levels. However, some studies suggest an increased risk for rejection for SLK recipients transplanted across high levels of pre-formed HLA DSA. Despite this, there is no consensus regarding acceptable levels of pre-formed DSA, the role of pre-transplant desensitization, splenectomy, or immunosuppressive management in this unique population. Also, the impact of post-transplant DSA monitoring on long-term outcomes is not well-studied in SLK recipients. In this article, we review recent and relevant past articles in this field with a focus on the immunological risk factors among SLK recipients, and strategies to mitigate the negative outcomes among them.

Predictors of Kidney Delayed Graft Function and Its Prognostic Impact following Combined Liver-Kidney Transplantation: A Recent Single-Center Experience

Combined liver−kidney transplantation (CLKT) improves patient survival among liver transplant recipients with renal dysfunction. However, kidney delayed graft function (kDGF) still represents a common and challenging complication that can negatively impact clinical outcomes. This retrospective study analyzed the incidence, potential risk factors, and prognostic impact of kDGF development following CLKT in a recently transplanted cohort. Specifically, 115 consecutive CLKT recipients who were transplanted at our center between January 2015 and February 2021 were studied. All transplanted kidneys received hypothermic pulsatile machine perfusion (HPMP) prior to transplant. The primary outcome was kDGF development. Secondary outcomes included the combined incidence and severity of developing postoperative complications; development of postoperative infections; biopsy-proven acute rejection (BPAR); renal function at 1, 3, 6, and 12 months post-transplant; and death-censored graft and patient survival. kDGF was observed in 37.4% (43/115) of patients. Multivariable analysis of kDGF revealed the following independent predictors: preoperative dialysis (p = 0.0003), lower recipient BMI (p = 0.006), older donor age (p = 0.003), utilization of DCD donors (p = 0.007), and longer delay of kidney transplantation after liver transplantation (p = 0.0003). With a median follow-up of 36.7 months post-transplant, kDGF was associated with a significantly increased risk of developing more severe postoperative complication(s) (p < 0.000001), poorer renal function (particularly at 1 month post-transplant, p < 0.000001), and worse death-censored graft (p = 0.00004) and patient survival (p = 0.0002). kDGF may be responsible for remarkable negative effects on immediate and potentially longer-term clinical outcomes after CLKT. Understanding the important risk factors for kDGF development in CLKT may better guide recipient and donor selection(s) and improve clinical decisions in this increasing group of transplant recipients.

Risk factors and outcomes for delayed kidney graft function in simultaneous heart and kidney transplant recipients: A UNOS/OPTN database analysis

There are no prior studies assessing the risk factors and outcomes for kidney delayed graft function (K-DGF) in simultaneous heart and kidney (SHK) transplant recipients. Using the OPTN/UNOS database, we sought to identify risk factors associated with the development of K-DGF in this unique population, as well as outcomes associated with K-DGF. A total of 1161 SHK transplanted between 1998 and 2018 were included in the analysis, of which 311 (27%) were in the K-DGF (+) group and 850 in the K-DGF (-) group. In the multivariable analysis, history of pretransplant dialysis (OR: 3.95; 95% CI: 2.94 to 5.29; p < .001) was significantly associated with the development of K-DGF, as was donor death from cerebrovascular accident and longer cold ischemia time of either organ. SHK recipients with K-DGF had increased mortality (HR: 1.99; 95% CI: 1.52 to 2.60; p < .001) and death censored kidney graft failure (HR: 3.51; 95% CI: 2.29 to 5.36; p < .001) in the multivariable analysis. Similar outcomes were obtained when limiting our study to 2008-2018. Similar to kidney-only recipients, K-DGF in SHK recipients is associated with worse outcomes. Careful matching of recipients and donors, as well as peri-operative management, may help reduce the risk of K-DGF and the associated detrimental effects.

Current and Evolving Indications for Simultaneous Liver Kidney Transplantation

This review will discuss the etiologies of kidney disease in liver transplant candidates, provide a historical background of the prior evolution of simultaneous liver-kidney (SLK) transplant indications, discuss the current indications for SLK including Organ Procurement and Transplantation Network policies and Model for End Stage Liver Disease exception points, as well as provide an overview of the safety net kidney transplant policy. Finally, the authors explore unanswered questions and future research needed in SLK transplantation.

Delayed kidney transplantation in combined liver-kidney transplantation

PURPOSE OF REVIEW

To review the impact of delayed kidney transplantation approach in combined (simultaneous) liver-kidney transplantation (CLKT).

RECENT FINDINGS

CLKT offers a life-saving procedure for patients with both end-stage liver disease and chronic kidney disease or prolonged acute kidney injury. It is the most common multiorgan transplant procedure in the US accounting for 9-10% of all liver transplants performed. The number of CLKT has also been increasing in other countries with a better understanding of hepato-renal syndrome. US is the only country which implemented a national allocation policy for CLKT in 2017. Due to the different physiological needs of liver and kidney allografts immediately after transplantation, delayed kidney transplantation approach in CLKT has been introduced for the first time by the Indiana Group, naming it as 'the Indiana Approach'. Over the years, many other groups in the US and in Europe published better outcomes in CLKT using the delayed kidney transplantation approach with the support of hypothermic machine perfusion.

SUMMARY

Several groups have shown that delayed kidney transplantation in CLKT is a safe procedure with better outcomes in graft(s) and patient survival.

Current status of combined liver-kidney transplantation

Combined liver-kidney transplantation is a life-saving procedure for patients with end-stage liver disease and underlying chronic kidney disease, or prolonged acute kidney injury. Due to physiologic changes secondary to portal hypertension in patients with end-stage liver disease, kidney injury is common, and combined liver-kidney transplantation accounts for 10% of all the liver transplants performed in the United States. Recently implemented policy in the United States standardizes the medical criteria for eligibility, and introduces a 'safety net' for those who are transplanted with a liver graft alone, in order to be able to receive a kidney graft later. Increasing number of combined liver-kidney transplants provides a large cohort of patients to be studied in detail for identification of factors (both donor and recipient-related) associated with better outcomes. Data regarding the safety and efficacy of delaying the kidney transplant part of the combined liver-kidney transplantation, and the immunologic benefits of the multi-organ transplantations including the liver are emerging. Here, we review the most recent analyses, and provide our opinion regarding the best practices in combined liver-kidney transplantation based on the evidence.

Delayed Graft Function in Simultaneous Liver Kidney Transplantation

BACKGROUND

Delayed graft function (DGF) is associated with inferior posttransplant outcomes in kidney transplantation. Given these adverse outcomes, we sought to determine the incidence, unique risk factors, and posttransplant outcomes for simultaneous liver kidney (SLK) transplant recipients developing DGF.

METHODS

We studied 6214 adult SLK recipients from March 2002 to February 2017 using the Scientific Registry of Transplant Recipients. We determined associations between risk factors and DGF using Poisson multivariate regression and between DGF and graft failure and mortality using Cox proportional hazard analysis.

RESULTS

The overall rate of DGF was 21.8%. Risk factors for DGF in the hepatitis C virus (HCV)-negative recipient population included pretransplant dialysis (adjusted incident rate ratio [aIRR] 3.26, P = 0.004), donor body mass index (aIRR 1.25 per 5 kg/m, P = 0.01), and transplantation with a donation after circulatory death (aIRR 5.38, P = 0.001) or imported donor organ (regional share aIRR 1.69, P = 0.03; national share aIRR 4.82, P < 0.001). DGF was associated with a 2.6-fold increase in kidney graft failure (adjusted hazard ratio [aHR] 2.63, P < 0.001), 1.6-fold increase in liver graft failure (aHR 1.62, P < 0.001), and 1.6-fold increase in mortality (aHR 1.62, P < 0.001).

CONCLUSIONS

In HCV-negative SLK recipients, recipient pretransplant dialysis and components of kidney graft quality comprise significant risk factors for DGF. Regardless of HCV status, DGF is associated with inferior posttransplant outcomes. Understanding these risk factors during clinical decision-making may improve prevention of DGF and may represent an opportunity to improve posttransplant outcomes.

Trends and Outcomes in Simultaneous Liver and Kidney Transplantation in Australia and New Zealand

AIM

Rates of simultaneous liver and kidney transplantation (SLKT) have increased, but indications for SLKT remain poorly defined. Additional data are needed to determine which patients benefit from SLKT to best direct use of scarce donor kidneys.

METHODS

Data were extracted from the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) database for all SLKT performed until the end of 2017. Patients were divided by pretransplant dialysis status into no dialysis before SLKT (preemptive kidney transplant) and any dialysis before SLKT (nonpreemptive). Baseline characteristics and outcomes were compared.

RESULTS

Between 1989 and 2017, inclusive, 84 SLKT procedures were performed in Australia, of which 24% were preemptive. Preemptive and nonpreemptive SLKT recipients did not significantly differ in age (P = .267), sex (P = .526), or ethnicity (P = .870). Over a median follow-up time of 4.5 years, preemptively transplanted patients had a statistically equivalent risk of kidney graft failure (hazard ratio (HR) 1.83, 95% confidence interval [CI]: 0.36-12.86, P = .474) and all-cause mortality (HR 1.69, 95% CI: 0.51-5.6, P = .226) compared to nonpreemptive patients. Overall, 1- and 5-year survival rates for all SLKTs were 92% (95% CI: 86-96) and 60% (95% CI: 45-75), respectively.

CONCLUSION

Kidney graft and overall patient survival were similar between patients with preemptive kidney transplant and those who were dialysis dependent.

Impact of Recipient Age in Combined Liver-Kidney Transplantation: Caution Is Needed for Patients ≥70 Years

Elderly recipients (≥70 y) account for 2.6% of all liver transplants (LTs) in the United States and have similar outcomes as younger recipients. Although the rate of elderly recipients in combined liver-kidney transplant (CLKT) is similar, limited data are available on how elderly recipients perform after CLKT.

METHODS

We have previously shown excellent outcomes in CLKT using delayed kidney transplant (Indiana) Approach (mean kidney cold ischemia time = 53 ± 14 h). Between 2007 and 2018, 98 CLKTs were performed using the Indiana Approach at Indiana University (IU) and the data were retrospectively analyzed. Recipients were subgrouped based on their age: 18-45 (n = 16), 46-59 (n = 34), 60-69 (n = 40), and ≥70 years (n = 8).

RESULTS

Overall, more elderly patients received LT at IU (5.2%) when compared nationally (2.6%). The rate of elderly recipients in CLKT at IU was 8.2% (versus 2% Scientific Registry of Transplant Recipient). Recipient and donor characteristics were comparable between all age groups except recipient age and duration of dialysis. Patient survival at 1 and 3 years was similar among younger age groups, whereas patient survival was significantly lower in elderly recipients at 1 (60%) and 3 years (40%) (P = 0.0077). Control analyses (replicating Scientific Registry of Transplant Recipient's survival stratification: 18-45, 46-64, ≥65 y) showed similar patient survival in all age groups.

CONCLUSIONS

Although LT can be safely performed in elderly recipients, extreme caution is needed in CLKT due to the magnitude of operation.

Nonimmunologic Factors Affecting Long-Term Outcomes of Deceased-Donor Kidney Transplant

OBJECTIVES

We investigated the impact of nonimmuno-logic factors on patient and graft survival after deceased-donor kidney transplant.

MATERIALS AND METHODS

All deceased-donor kidney transplants performed between January 2004 and December 2015 were included in our analyses. We used the independent t test to calculate significant differences between means above and below medians of various parameters.

RESULTS

All study patients (N = 205; 58.7% males) received antithymocyte globulin as induction therapy and standard maintenance therapy. Patients were free from infection, malignancy, and cardiac, liver, and pulmonary system abnormalities. Most patients (89.2%) were recipients of a first graft. Median patient age, weight, and cold ischemia time were 38 years, 65 kg, and 15 hours, respectively. Delayed graft function, diabetes mellitus, and hypertension occurred in 19.1%, 43.4%, and 77.9% of patients, respectively. The 1- and 5-year graft survival rates were 95% and 73.8%. Graft survival was not affected by donor or recipient sex or recipient diabetes or hypertension. However, graft survival was longer in patients who received no graft biopsy (8.2 vs 6.9 y; P = .027) and in those who had diagnosis of calcineurin inhibitor nephrotoxicity versus antibody-mediated rejection after biopsy (8.19 vs 3.66 y; P = .0047). Longer survival was shown with donors who had traumatic death versus cerebro-vascular accident (5.9 vs 5.3 y; P = .029) and donors below the 50th percentile in age (8.23 and 7.14 y; P = .0026) but less with donors who had terminal acute kidney injury (6.97 vs 8.16 y; P = .0062). We found a negative correlation between graft survival and donor age (P = .01) and 1-year serum creatinine (P = .01).

CONCLUSIONS

Donor age, cause of brain death, and acute kidney injury affected graft survival in our study cohort but not donor or recipient sex or posttransplant or donor blood pressure.

Factors predicting kidney delayed graft function among recipients of simultaneous liver-kidney transplantation: A single-center experience

BACKGROUND

Kidney delayed graft function (kDGF) remains a challenging problem following simultaneous liver and kidney transplantation (SLKT) with a reported incidence up to 40%. Given the scarcity of renal allografts, it is crucial to minimize the development of kDGF among SLKT recipients to improve patient and graft outcomes. We sought to assess the role of preoperative recipient and donor/graft factors on developing kDGF among recipients of SLKT.

METHODS

A retrospective review of 194 patients who received SLKT in the period from January 2004 to March 2017 in a single center was performed to assess the effect of preoperative factors on the development of kDGF.

RESULTS

Kidney delayed graft function was observed in 95 patients (49%). Multivariate analysis revealed that donor history of hypertension, cold static preservation of kidney grafts [versus using hypothermic pulsatile machine perfusion (HPMP)], donor final creatinine, physiologic MELD, and duration of delay of kidney transplantation after liver transplantation were significant independent predictors for kDGF. kDGF is associated with worse graft function and patient and graft survival.

CONCLUSIONS

Kidney delayed graft function has detrimental effects on graft function and graft survival. Understanding the risks and combining careful perioperative patient management, proper recipient selection and donor matching, and graft preservation using HPMP would decrease kDGF among SLKT recipients.

Combined liver-kidney transplantation versus liver transplant alone based on KDIGO stratification of estimated glomerular filtration rate: data from the United Kingdom Transplant registry - a retrospective cohort study

Patient selection for combined liver-kidney transplantation (CLKT) is a current issue on the background of organ shortage. This study aimed to compare outcomes and post-transplant renal function for patients receiving CLKT and liver transplantation alone (LTA) based on native renal function using estimated glomerular filtration rate (eGFR) stratification. Using the UK National transplant database (NHSBT) 6035 patients receiving a LTA (N = 5912; 98%) or CLKT (N = 123; 2%) [2001-2013] were analysed, and stratified by KDIGO stages of eGFR at transplant (eGFR group-strata). There was no difference in patient/graft survival between LTA and CLKT in eGFR group-strata (P > 0.05). Of 377 patients undergoing renal replacement therapy (RRT) at time of transplantation, 305 (81%) and 72 (19%) patients received LTA and CLKT respectively. A significantly greater proportion of CLKT patients had severe end-stage renal disease (eGFR < 30 ml/min/1.73 m² ) at 1 year post-transplant compared to LTA (9.5% vs. 5.7%, P = 0.001). Patient and graft survival benefit for patients on RRT at transplantation was favouring CLKT versus LTA (P = 0.038 and P = 0.018, respectively) but the renal function of the long-term survivors was not superior following CLKT. The data does not support CLKT approach based on eGFR alone, and the advantage of CLKT appear to benefit only those who are on established RRT at the time of transplant.

Liver alone or simultaneous liver-kidney transplant? Pretransplant chronic kidney disease and post-transplant outcome - a retrospective study

The new Organ Procurement and Transplant Network/United Organ Sharing Network (OPTN/UNOS) simultaneous liver-kidney transplant (SLK) policy has been implemented. The aim of this study was to review liver transplant outcomes utilizing the new SLK policy. Liver transplant alone (LTA) and SLK patients between 2009 and 2015 were reviewed. Graft survival and post-transplant kidney function were investigated among LTA patients meeting the chronic kidney disease (CKD) criteria of the new policy (LTA-CKD group). To validate our findings, we reviewed and applied our analysis to the OPTN/UNOS registry. A total of 535 patients were eligible from our series. The LTA-CKD group (n = 27) showed worse 1-year graft survival, compared with the SLK group (n = 44), but not significant (81% vs. 93%, P = 0.15). The LTA-CKD group significantly increased a risk of post-transplant dialysis (odds ratio = 5.59 [95% CI = 1.27-24.7], P = 0.02 [Ref. normal kidney function]). Post-transplant dialysis was an independent risk factor for graft loss (hazard ratio = 7.25, 95% CI = 3.3-15.91, P < 0.001 [Ref. SLK]). In the validation analysis based on the OPTN/UNOS registry, the hazard of 1-year-graft loss in the LTA-CKD group (n = 751) was 34.8% higher than the SLK group (n = 2856) (hazard ratio = 1.348, 95% CI = 1.157-1.572, P < 0.001). Indicating SLK for patients who meet the CKD criteria may significantly improve transplant outcomes.

Excellent outcomes in combined liver-kidney transplantation: Impact of kidney donor profile index and delayed kidney transplantation

The positive impact of delayed kidney transplantation (KT) on patient survival for combined liver-kidney transplantation (CLKT) has already been demonstrated by our group. The purpose of this study is to identify whether the quality of the kidneys (based on kidney donor profile index [KDPI]) or the delayed approach KT contributes to improved patient survival. In total, 130 CLKTs were performed between 2002 and 2015, 69 with simultaneous KT (group S) and 61 with delayed KT (group D) (performed as a second operation with a mean cold ischemia time [CIT] of 50 ± 15 hours). All patients were categorized according to the KDPI score: 1%-33%, 34%-66%, and 67%-99%. Recipient and donor characteristics were comparable within groups S and D. Transplant outcomes were comparable within groups S and D, including liver and kidney CIT, warm ischemia time, and delayed graft function. Lower KDPI kidneys (<34%) were associated with increased patient survival in both groups. The combination of delayed KT and KDPI 1%-33% resulted in 100% patient survival at 3 years. These results support that delayed KT in CLKT improves patient survival. The combination of delayed KT and low KDPI offers excellent patient survival up to 3 years. Improved outcomes in the delayed KT group including high KDPI kidneys supports expansion of the donor pool with the use of more extended criteria donor and donation after circulatory death kidneys. Liver Transplantation 24 222-232 2018 AASLD.

Differential Simultaneous Liver and Kidney Transplant Benefit Based on Severity of Liver Damage at the Time of Transplantation

Background

We evaluated the concept of whether liver failure patients with a superimposed kidney injury receiving a simultaneous liver and kidney transplant (SLKT) have similar outcomes compared to patients with liver failure without a kidney injury receiving a liver transplantation (LT) alone.

Methods

Using data from the United Network of Organ Sharing (UNOS) database, patients were divided into five groups based on pre-transplant model for end-stage liver disease (MELD) scores and categorized as not having (serum creatinine (sCr) ≤ 1.5 mg/dL) or having (sCr > 1.5 mg/dL) renal dysfunction. Of 30,958 patients undergoing LT, 14,679 (47.5%) had renal dysfunction, and of those, 5,084 (16.4%) had dialysis.

Results

Survival in those (liver failure with renal dysfunction) receiving SLKT was significantly worse (P < 0.001) as compared to those with sCr < 1.5 mg/dL (liver failure only). The highest mortality rate observed was 21% in the 36+ MELD group with renal dysfunction with or without SLKT. In high MELD recipients (MELD > 30) with renal dysfunction, presence of renal dysfunction affects the outcome and SLKT does not improve survival. In low MELD recipients (16 - 20), presence of renal dysfunction at the time of transplantation does affect post-transplant survival, but survival is improved with SLKT.

Conclusions

SLKT improved 1-year survival only in low MELD (16 - 20) recipients but not in other groups. Performance of SLKT should be limited to patients where a benefit in survival and post-transplant outcomes can be demonstrated.

SIMULTANEOUS LIVER KIDNEY TRANSPLANTATION IN LIVER TRANSPLANT CANDIDATES WITH RENAL DYSFUNCTION: IMPORTANCE OF CREATININE LEVELS, DIALYSIS, AND ORGAN QUALITY IN SURVIVAL

Introduction

The survival benefit from simultaneous liver-kidney transplantation (SLK) over liver transplant alone (LTA) in recipients with moderate renal dysfunction is not well understood. Moreover, the impact of deceased donor organ quality in SLK survival has not been well described in the literature.

Methods

The Scientific Registry of Transplant Recipients was studied for adult recipients receiving LTA (N = 2700) or SLK (N = 1361) with moderate renal insufficiency between 2003 and 2013. The study cohort was stratified into 4 groups based on serum creatinine (<2 mg/dl versus ≥2 mg/dl) and dialysis status at listing and transplant. The patients with end-stage renal disease and requiring acute dialysis more than 3 months before transplantation were excluded. A propensity score matching was performed in each stratified group to factor out imbalances between the SLK and LTA regarding covariate distribution and to reduce measured confounding. Donor quality was assessed with liver donor risk index. The primary outcome of interest was posttransplant mortality.

Results

In multivariable propensity score-matched Cox proportional hazard models, SLK led to decrease in posttransplant mortality compared with LTA across all 4 groups, but only reached statistical significance (hazard ratio 0.77; 95% confidence interval, 0.62–0.96) in the recipients not exposed to dialysis and serum creatinine ≥ 2 mg/dl at transplant (mortality incidence rate per patient-year 5.7% in SLK vs. 7.6% in LTA, P = 0.005). The decrease in mortality was observed among SLK recipients with better quality donors (liver donor risk index < 1.5).

Discussion

Exposure to pretransplantation dialysis and donor quality affected overall survival among SLK recipients.

Results of Simultaneous Liver and Kidney Transplantation: A Single-Center Review

BACKGROUND

The decision for a simultaneous liver and kidney transplantation (SLKT) is fraught with controversy. The aim of this study was to compare SLKT with liver transplantation alone (LTA) in patients with pretransplantation renal failure.

STUDY DESIGN

A retrospective review comparing patients undergoing SLKT and LTA (with renal failure) between January 2000 and December 2014 was performed.

RESULTS

Of 1,129 liver transplantations, 132 had renal failure pretransplantation; 52 had SLKT and 80 recipients had LTA. Model for End-Stage Liver Disease score and BMI were lower in the SLKT group (p = 0.001). Simultaneous liver and kidney transplantation patients had better overall survival rates at 1 and 5 years compared with LTA (92.3% and 81.6% vs 73.3% and 64.3% respectively; p < 0.01). Graft survival was also superior in patients undergoing SLKT vs LTA. Six of 52 (11.5%) SLKT patients had final positive cross match, but only 1 of 52 (1.9%) kidney grafts was lost to rejection. In the SLKT group, 9 of 52 (17.3%) patients required dialysis post transplantation, but only 2 remained on dialysis beyond 30 days. All patients in the LTA group were on dialysis pretransplantation and significantly more patients (52 of 80 [65%]) required dialysis post LTA (p ≤ 0.0001); 31 of 80 (38.8%) were dialysis dependent for more than 30 days or died on dialysis within 30 days. Two LTA recipients were subsequently listed for kidney transplant.

CONCLUSIONS

Patients with end-stage liver disease on dialysis who undergo liver transplantation have significantly better survival when SLKT is performed. In selected patients, SLKT is an appropriate use of a scarce resource, but better prognostic indicators for selection of patients are still needed.

Decreased chronic cellular and antibody-mediated injury in the kidney following simultaneous liver-kidney transplantation

In simultaneous liver-kidney transplantation (SLK), the liver can protect the kidney from hyperacute rejection and may also decrease acute cellular rejection rates. Whether the liver protects against chronic injury is unknown. To answer this we studied renal allograft surveillance biopsies in 68 consecutive SLK recipients (14 with donor-specific alloantibodies at transplantation [DSA+], 54 with low or no DSA, [DSA-]). These were compared with biopsies of a matched cohort of kidney transplant alone (KTA) recipients (28 DSA+, 108 DSA-). Overall 5-year patient and graft survival was not different: 93.8% and 91.2% in SLK, and 91.9% and 77.1% in KTA. In DSA+ recipients, KTA had a significantly higher incidence of acute antibody-mediated rejection (46.4% vs. 7.1%) and chronic transplant glomerulopathy (53.6% vs. 0%). In DSA- recipients at 5 years, KTA had a significantly higher cumulative incidence of T cell-mediated rejection (clinical plus subclinical, 30.6% vs. 7.4%). By 5 years, DSA+ KTA had a 44% decline in mean GFR while DSA+SLK had stable GFR. In DSA- KTA, the incidence of a combined endpoint of renal allograft loss or over a 50% decline in GFR was significantly higher (20.4% vs. 7.4%). Simultaneously transplanted liver allograft was the most predictive factor for a significantly lower incidence of cellular (odds ratio 0.13, 95% confidence interval 0.06-0.27) and antibody-mediated injury (odds ratio 0.11, confidence interval 0.03-0.32), as well as graft functional decline (odds ratio 0.22, confidence interval 0.06-0.59). Thus, SLK is associated with reduced chronic cellular and antibody-mediated alloimmune injury in the kidney allograft.

HCV infection is associated with lower survival in simultaneous liver kidney transplant recipients in the United States

BACKGROUND

The frequency of simultaneous liver kidney transplantation (SLKT) has been increasing over the past decade. Hepatitis C virus (HCV) infection is the most common indication for liver transplantation in the United States. Given the rising prevalence of HCV-related SLKT, it is important to understand the impact of HCV in this patient population.

METHODS

We conducted a retrospective cohort study using data from the United Network for Organ Sharing registry to assess adult patients undergoing SLKT in the United States from 2003 to 2012. Patient survival following SLKT was assessed using Kaplan-Meier methods and multivariate Cox proportional hazards models.

RESULTS

Patients infected with non-HCV have significantly lower survival following SLKT compared to non-HCV patients at three (three-yr survival: 71.0% vs. 78.9%, p < 0.01) and five yr (five-yr survival: 61.4% vs. 72.5%, p < 0.01). The results of multivariate regression analyses demonstrated that patients infected with HCV had significantly lower survival following SLKT than patients with non-HCV disease (HR 1.41, 95% CI, 1.19-1.67, p < 0.001). In addition, lower post-SLKT survival was noted among patients with diabetes (HR 1.34, 95% CI, 1.13-1.58, p < 0.001) and hepatocellular carcinoma (HR 1.60, 95% CI, 1.17-2.18, p < 0.01).

CONCLUSIONS

Hepatitis C infection is associated with lower patient survival following SLKT.

Combined liver-kidney transplantation: experience at a Brazilian university hospital

BACKGROUND

Combined liver-kidney transplant is a routine procedure in many transplant centers. The increase in its number coincided with the introduction in 2002 of the MELD (Model for End-stage Liver Disease) score for allocation of livers, prioritizing patients with renal dysfunction. Aim : To analyze the experience with combined liver-kidney transplantation in a liver transplant center in Brazil.

METHOD

A retrospective review was conducted. All transplants were performed using grafts from deceased donors.

RESULTS

Sixteen combined liver-kidney transplantations were performed in the same period, which corresponds to 2.7% and 2.5% of the kidney and liver transplants, respectively. Fourteen patients were male (87.5 %) and two were female (12.5%). The average patients and donors age was 57.3 ± 9.1 and 32.7 ± 13.1, respectively. The MELD score mean was 23.6 ± 3.67. The main cause of liver dysfunction were chronic hepatitis C virus (n=9). As for renal dysfunction, diabetic nephropathy (n=4) was the most frequent. There were six deaths, two of them by severe dysfunction of the liver graft and four by infectious causes. The 1, 3 and 5 years survival rate in patients undergoing liver-kidney transplantations was 68.8%, 57.3% and 57.3%, respectively.

CONCLUSION

The survival rates achieved in this series are considered satisfactory and show that this procedure has an acceptable morbidity and survival.

Renal outcomes of simultaneous liver-kidney transplantation compared to liver transplant alone for candidates with renal dysfunction

It is unclear whether a concomitant kidney transplant grants survival benefit to liver transplant (LT) candidates with renal dysfunction (RD). We retrospectively studied LT candidates without RD (n = 714) and LT candidates with RD who underwent either liver transplant alone (RD-LTA; n = 103) or simultaneous liver-kidney transplant (RD-SLKT; n = 68). RD was defined as renal replacement therapy (RRT) requirement or modification of diet in renal disease (MDRD)-glomerular filtration rate (GFR) <25 mL/min/1.73 m(2) . RD-LTAs had worse one-yr post-transplant survival compared to RD-SLKTs (79.6% vs. 91.2%, p = 0.05). However, RD-LTA recipients more often had hepatitis C (60.2% vs. 41.2%, p = 0.004) and more severe liver disease (MELD 37.9 ± 8.1 vs. 32.7 ± 9.1, p = 0.0001). Twenty RD-LTA recipients died in the first post-transplant year. Evaluation of the cause and timing of death relative to native renal recovery revealed that only four RD-LTA recipients might have derived survival benefit from RD-SLKT. Overall, 87% of RD-LTA patients recovered renal function within one month of transplant. One yr after RD-LTA or RD-SLKT, serum creatinine (1.5 ± 1.2 mg/dL vs. 1.4 ± 0.5 mg/dL, p = 0.63) and prevalence of stage 4 or 5 chronic kidney disease (CKD; 5.9% vs. 6.8%, p = 0.11) were comparable. Our series provides little evidence that RD-SLKT would have yielded substantial short-term survival benefit to RD-LTA recipients.

Excessive immunosuppression as a potential cause of poor survival in simultaneous liver/kidney transplantation for hepatitis C

Appropriate recipient selection of simultaneous liver/kidney transplantation (SLKT) remains controversial. In particular, data on liver graft survival in hepatitis C virus-infected (HCV+) SLKT recipients are lacking. We conducted a single-center, retrospective study of HCV+ SLKT recipients (N = 25) in comparison with HCV- SLKT (N = 26) and HCV+ liver transplantation alone (LTA, N = 296). Despite backgrounds of HCV+ and HCV- SLKT being similar, HCV+ SLKT demonstrated significantly impaired 5-year liver graft survival of 35% (HCV- SLKT, 79%, P = 0.004). Compared with HCV+ LTA, induction immunosuppression was more frequently used in HCV+ SLKT. Five-year liver graft survival rate for HCV+ SLKT was significantly lower than that for LTA (35% vs. 74%, respectively, P < 0.001). Adjusted hazard ratio of liver graft loss in HCV+ SLKT was 4.9 (95% confidence interval 2.0-12.1, P = 0.001). HCV+ SLKT recipients were more likely to succumb to recurrent HCV and sepsis compared with LTA (32% vs. 8.8%, P < 0.001 and 24% vs. 8.8%, P = 0.030, respectively). Ten HCV+ SLKT recipients underwent anti-HCV therapy for recurrent HCV; only 1 achieved sustained virological response. HCV+ SLKT is associated with significantly decreased long-term prognosis compared with HCV- SLKT and HCV+ LTA.

Diagnosing hepatitis C virus and improved outcomes in overall and kidney graft survival among simultaneous liver-kidney transplant recipients in the post-MELD era

OBJECTIVES

We compared survival outcomes among simultaneous liver-kidney transplants after model for end-stage liver disease (MELD) according to their specific diagnosis and hepatitis C virus versus nonhepatitis C virus.

MATERIALS AND METHODS

Clinical data review was performed for all patients who underwent combined liver-kidney transplants at Johns Hopkins Hospital from January 31, 1995, to October 31, 2012. Differences in demographics and characteristics among 2 groups were compared using independent samples t test. Survival analysis and distributions were calculated using Kaplan-Meier and Mantel-Cox log-rank test.

RESULTS

Of 48 combined liver-kidney transplants, 31 simultaneous liver-kidney transplants cases were included; nonsimultaneous liver-kidney transplants and patients with prior transplants were excluded. Proportions of age, sex, ethnicity, pre-MELD score, pretransplant renal replacement therapy requirement, hypertension, diabetes mellitus, and follow-up were similar in both groups. Median follow-up was 30 months. Overall and graft survival rates among simultaneous liver-kidney transplants recipients in the pre-MELD era were significantly superior to simultaneous liver-kidney transplants patients in the post-MELD era (P = .0473). However, overall and graft survival rates among simultaneous liver-kidney transplants recipients who had hepatitis C virus and non-hepatitis C virus causes were not statistically different.

CONCLUSIONS

We demonstrated a statistically significant difference in overall and kidney graft survival between the post-MELD era and the pre-MELD era. Subgroup analyses of this group showed no statistically significant difference in overall and kidney-graft survival when compared with their specific diagnosis of hepatitis C virus. This must be further studied and verified in a larger cohort of patients to fully identify the effect of hepatitis C virus infection in this group of patients because it can affect both liver and kidney grafts after transplant.

Renal interactions in liver dysfunction and failure

PURPOSE OF REVIEW

This review will summarize the recent advances in our understanding of the relationship between liver and kidney function. It will outline the new concepts of the pathophysiology of renal dysfunction in chronic liver disease and examine novel renal biomarkers to detect acute kidney injury (AKI) in cirrhosis and following liver transplantation. We will further review new treatments for hepatorenal syndrome (HRS) and approaches to kidney dysfunction in liver transplantation recipients.

RECENT FINDINGS

Recent studies evaluated the effect of the renin-angiotensin system on hepatic fibrosis and the role of the gut in mediating AKI after hepatic ischemia reperfusion injury. Multiple studies have investigated novel biomarkers such as neutrophil gelatinase-associated lipocalin to predict AKI (and HRS) in cirrhosis and after liver transplantation. Furthermore, there were recent advances in the management of kidney dysfunction including management of HRS with vasopressin analogs and kidney-sparing immunosuppression after liver transplantation.

SUMMARY

Greater knowledge of the physiologic relationship between kidney and liver may open avenues for specific therapies of liver and kidney injury. Renal biomarkers may allow early diagnosis and targeted treatment of AKI, and improved management of kidney disease in the preliver and postliver transplantation setting will be crucial to improving long-term outcomes in these patients.