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

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.

One size does not fit all: Differential benefits of simultaneous liver-kidney transplantation by eligibility criteria

Standard eligibility criteria for simultaneous liver-kidney transplantation (SLK) are in place in the United States. We hypothesize that the benefit associated with SLK over liver transplant alone differs by patient, depending on the specific SLK criteria met. We analyzed a retrospective US cohort of 5446 adult liver transplant or SLK recipients between January 1, 2015, and December 31, 2018, who are potentially qualified for SLK. Exposure was a receipt of SLK. We tested effect modification by the specific SLK eligibility criteria met (end-stage kidney disease, acute kidney injury, chronic kidney disease, or unknown). The primary outcome was death within 1 year of a liver transplant. We used a modified Cox regression analysis containing an interaction term of SLK * time from transplant. Two hundred ten (9%) SLK recipients and 351 (11%) liver-alone recipients died in 1 year. In the overall population, SLK was associated with a mortality benefit over liver transplant on the day of the transplant, without adjustment [HR: 0.59 (95% CI, 0.46-0.76)] and with adjustment [aHR: 0.50 (95% CI, 0.35-0.71)]. However, when SLK eligibility criteria were included, only in patients with end-stage kidney disease was SLK associated with a sustained survival benefit at day 0 [HR: 0.17 (0.08-0.35)] up to 288 (95% CI, 120-649) days post-transplant. Benefit within the first year post-transplant associated with SLK over liver-alone transplantation was only pronounced in patients with end-stage kidney disease but not present in patients meeting other criteria for SLK. A "strict SLK liberal Safety Net" strategy may warrant consideration at the national policy level.

The Impact of the 2017 Kidney Allocation Policy Change on Simultaneous Liver-Kidney Utilization and Outcomes

Historically in the United States, kidneys for simultaneous liver-kidney transplantation (SLKT) candidates were allocated with livers, prioritizing SLKT recipients over much of the kidney waiting list. A 2017 change in policy delineated renal function criteria for SLKT and implemented a safety net for kidney-after-liver transplantation. We compared the use and outcomes of SLKT and kidney-after-liver transplant with the 2017 policy. United Network for Organ Sharing Standard Transplant Analysis and Research files were used to identify adults who received liver transplantations (LT) from August 10, 2007 to August 10, 2012; from August 11, 2012 to August 10, 2017; and from August 11, 2017 to June 12, 2019. LT recipients with end-stage renal disease (ESRD) were defined by dialysis requirement or estimated glomerular filtration rate <25. We evaluated outcomes and center-level, regional, and national practice before and after the policy change. Nonparametric cumulative incidence of kidney-after-liver listing and transplant were modeled by era. A total of 6332 patients received SLKTs during the study period; fewer patients with glomerular filtration rate (GFR) ≥50 mL/min underwent SLKT over time (5.8%, 4.8%, 3.0%; P = 0.01 ). There was also less variability in GFR at transplant after policy implementation on center and regional levels. We then evaluated LT-alone (LTA) recipients with ESRD (n = 5408 from 2012-2017; n = 2321 after the policy). Listing for a kidney within a year of LT increased from 2.9% before the policy change to 8.8% after the policy change, and the rate of kidney transplantation within 1 year increased from 0.7% to 4% (P < 0.001). After the policy change, there was no difference in patient survival rates between SLKT and LTA among patients with ESRD. Implementation of the 2017 SLKT policy change resulted in reduced variability in SLKT recipient kidney function and increased access to deceased donor kidney transplantation for LTA recipients with kidney disease without negatively affecting 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.

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.

Liver Transplantation Followed by Renal Transplantation on Extracorporeal Membrane Oxygenation: A Case Report

We report the case of a 68-year-old woman with end-stage liver disease and end-stage renal disease scheduled for simultaneous liver and kidney transplant. Intraoperatively, she became hemodynamically unstable during her liver transplant surgery, and her renal transplant had to be postponed. On the following day, she required extracorporeal membrane oxygenation and ABIOMED Impella support for managing her severe cardiovascular decompensation. At the same time, the renal transplant was conducted to use the donor kidney already allocated for this patient. The patient was successfully managed postoperatively in the cardiothoracic intensive care unit and was discharged after 2 months. This case is unique because there are no similar cases previously reported in which renal transplantation was performed with extracorporeal membrane oxygenation and Impella support following cardiogenic shock after a liver transplant.

Association of Pretransplant Renal Function With Liver Graft and Patient Survival After Liver Transplantation in Patients With Nonalcoholic Steatohepatitis

Nonalcoholic steatohepatitis (NASH) is one of the top 3 indications for liver transplantation (LT) in Western countries. It is unknown whether renal dysfunction at the time of LT has any effect on post-LT outcomes in recipients with NASH. From the United Network for Organ Sharing-Standard Transplant Analysis and Research data set, we identified 4088 NASH recipients who received deceased donor LT. We divided our recipients a priori into 3 categories: group 1 with estimated glomerular filtration rate (eGFR) <30 mL/minute/1.73 m2 at the time of LT and/or received dialysis within 2 weeks preceding LT (n = 937); group 2 with recipients who had eGFR ≥30 mL/minute/1.73 m2 and who did not receive renal replacement therapy prior to LT (n = 2812); and group 3 with recipients who underwent simultaneous liver-kidney transplantation (n = 339). We examined the association of pretransplant renal dysfunction with death with a functioning graft, all-cause mortality, and graft loss using competing risk regression and Cox proportional hazards models. The mean ± standard deviation age of the cohort at baseline was 58 ± 8 years, 55% were male, 80% were Caucasian, and average exception Model for End-Stage Liver Disease score was 24 ± 9. The median follow-up period was 5 years (median, 1816 days; interquartile range, 1090-2723 days). Compared with group 1 recipients, group 2 recipients had 19% reduced trend for risk for death with a functioning graft (subhazard ratio [SHR], 0.81; 95% confidence interval [CI], 0.64-1.02) and similar risk for graft loss (SHR, 1.25; 95% CI, 0.59-2.62), whereas group 3 recipients had similar risk for death with a functioning graft (SHR, 1.23; 95% CI, 0.96-1.57) and graft loss (SHR, 0.18; 95% CI, 0.02-1.37) using an adjusted competing risk regression model. In conclusion, recipients with preserved renal function before LT showed a trend toward lower risk of death with a functioning graft compared with SLKT recipients and those with pretransplant severe renal dysfunction in patients with NASH.

Safety and efficacy of antibiotics among acutely decompensated cirrhosis patients

BACKGROUND AND AIM

Infection is a leading precipitant of acute-on-chronic liver failure. This study aims to determine the safety and efficacy of antibiotics within acute-on-chronic liver failure.

METHODS

Retrospective study of 457 acute-on-chronic liver failure patients admitted to the University of Arizona Health Network between January 1 and December 31, 2014. Eligibility criteria were as follows: at least 18 years of age and 6 months follow-up, data available to calculate systemic inflammatory response syndrome (SIRS), and acute-on-chronic liver failure. This study collected patient's clinical features and historical data. Key data points were infection, antibiotic use, and SIRS. This study used Cox proportional hazards to model the effects of clinical factors on risk of death.

RESULTS

A total of 521 of 1243 met the inclusion criteria, and 64 had missing data, leaving 457 patients. Infection resulted in higher hazard (hazard ratio [HR] = 1.6, confidence interval [CI]: 1.1-1.3, P = 0.01). Patients with infections and antibiotics, compared with non-infected patients without antibiotics, had higher hazard (HR = 1.633, CI: 1.022-2.609, P = .04). Of those infected patients with antibiotics, SIRS patients experienced higher hazard (HR = 1.9, CI: 1.1-3.0, P = .007). Multivariable Cox proportional hazards associated the following with higher hazard: SIRS (HR = 1.866, CI: 1.242-2.804, P = 0.003), vancomycin (HR = 1.640, CI: 1.119-2.405, P = 0.011), Model for End-Stage Liver Disease (HR = 1.051, CI: 1.030-1.073, P < 0.001), gastrointestinal bleeding (HR = 1.727, CI: 1.180-2.527, P = 0.005), and hepatic encephalopathy (HR = 1.807, CI: 1.247-2.618, P = 0.002).

CONCLUSION

Overall, treatment of infection with antibiotics did not improve survival; however, patients not meeting SIRS criteria had better outcomes, and vancomycin was associated with poorer survival among acute-on-chronic liver failure patients.

Outcomes of simultaneous liver-kidney transplantation: implications for patient selection

PURPOSE OF REVIEW

Rates of simultaneous liver kidney (SLK) transplantation have continued to increase despite lack of clear allocation guidelines and outcomes data. The organ procurement and transplantation network (OPTN)/UNOS board approved a new SLK allocation policy to standardize medical eligibility and optimize organ utilization. This review highlights the rationale behind these new selection criteria and posttransplant outcomes in various patient populations.

RECENT FINDINGS

Uniform criteria for SLK transplantation were adopted in August 2017 and state SLK should be reserved for select patients with cirrhosis who have chronic kidney disease for longer than 3 months, sustained acute kidney injury, or particular metabolic diseases. Many patients who previously underwent SLK did not meet these criteria, reducing organ availability for patients awaiting kidney-alone transplantation. The new criteria includes a 'safety net' policy allowing for renal transplant priority for liver-alone recipients who do not meet criteria for SLK but fail to have renal recovery within the first year.

SUMMARY

The new SLK allocation policy was adopted to avoid kidney transplantation in those patients who have a significant chance of recovering renal function post-liver transplant and those with a poor chance of survival in whom SLK is futile.

Environmental peer pressure: CD4+ T cell help in tolerance and transplantation

The liver participates in a multitude of metabolic functions that are critical for sustaining human life. Despite constant encounters with antigenic-rich intestinal blood, oxidative stress, and metabolic intermediates, there is no appreciable immune response. Interestingly, patients undergoing orthotopic liver transplantation benefit from a high rate of graft acceptance in comparison to other solid organ transplant recipients. In fact, cotransplantation of a donor liver in tandem with a rejection-prone graft increases the likelihood of graft acceptance. A variety of players may account for this phenomenon including the interaction of intrahepatic antigen-presenting cells with CD4⁺ T cells and the preferential induction of forkhead box P3 (Foxp3) expression on CD4⁺ T cells following injurious stimuli. Ineffective insult management can cause chronic liver disease, which manifests systemically as the following: antibody-mediated disorders, ineffective antiviral and antibacterial immunity, and gastrointestinal disorders. These sequelae sharing the requirement of CD4⁺ T cell help to coordinate aberrant immune responses. In this review, we will focus on CD4⁺ T cell help due to the shared requirements in hepatic tolerance and coordination of extrahepatic immune responses. Overall, intrahepatic deviations from steady state can have deleterious systemic immune outcomes and highlight the liver's remarkable capacity to maintain a balance between tolerance and inflammatory response while simultaneously being inundated with a panoply of antigenic stimuli. Liver Transplantation 24 89-97 2018 AASLD.