Analysis of the United Network for Organ Sharing database comparing renal allografts and patient survival in combined liver-kidney transplantation with the contralateral allografts in kidney alone or kidney-pancreas 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.

Kidney after liver transplantation does not have an increased risk of rejection compared to liver alone

BACKGROUND

Simultaneous liver kidney (SLK) transplant protects against acute cellular rejection. In 2017, UNOS implemented a "safety net" policy to allow patients with renal recovery to avoid renal transplantation. Whether kidney after liver transplantation (KALT) increases the risk of rejection is unknown.

METHODS

We performed a retrospective analysis of the Organ Procurement and Transplantation Network (OPTN) database of adult patients who received liver transplant, SLK or KALT between 2010 and 2020. We examined rejection of the liver within 6 months and 1 year of the liver transplant, as well as rejection of the kidney within 6 months and 1 year of receiving the kidney, as well as patient and graft loss.

RESULTS

Sixty-six thousand seventy-nine patients were transplanted; 60 168 with liver transplant alone, 5627 with SLK, and 284 with KALT. Acute or chronic liver rejection rates within 6 or 12 months were statistically higher in the KALT group (10.0% and 10.9%) compared to the SLK group (6.1% and 7.5%), but comparable to the LTA group (9.3% and 11.1%). Kidney rejection and graft survival rates were not different. Liver graft survival was worse in KALT than SLK or LTA (Kaplan-Meier estimates .61 vs. .89 and .90), but these patients were more ill at the time of transplantation. KDPI and LDRI scores were notably lower in the SLK than KALT group. Patient survival was not clinically different between the groups.

CONCLUSION

KALT does not increase the risk of acute or chronic kidney rejection. SLK has a lower risk of early liver rejection, but this effect diminishes by one year to being not clinically different compared to KALT. Given that KALT is immunologically safe, and potentially avoids unnecessary renal graft use, it should be preferred over SLK.

BRIEF SUMMARY

Patients undergoing sequential kidney after liver transplant do not have an increased risk of liver or kidney rejection when compared to liver transplant alone or simultaneous liver and kidney transplant.

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.

Issues in multi-organ transplantation of the liver with kidney or heart in polycystic liver-kidney disease or congenital heart disease: Current practices and immunological aspects

Solid organ transplantation has become an integral part of the management of patients with end-stage diseases of the kidney, liver, heart and lungs. Most procedures occur in isolation, but multi-organ transplantation of the liver with either the kidney or heart has become an option. As more patients with congenital heart disease and cardiac cirrhosis survive into adulthood, particularly after the Fontan procedure, liver transplant teams are expected to face questions regarding multi-organ (heart-liver) transplantation. Similarly, patients with polycystic kidneys and livers may be managed by multi-organ transplantation. Herein, we review the indications and outcomes of simultaneous liver-kidney transplantation for polycystic liver-kidney disease, and discuss the indications, timing and procedural aspects of combined heart-liver transplantation. We also summarise the evidence for, and potential mechanisms underlying, the immunoprotective impact of liver allografts on the simultaneously transplanted organs.

Incidence of acute rejection and patient survival in combined heart-liver transplantation

Combined heart-liver transplantation (CHLT) is indicated for patients with concomitant end-stage heart and liver disease or patients with amyloid heart disease where liver transplantation mitigates progression. Limited data suggest that the liver allograft provides immunoprotection for heart and kidney allografts in combined transplantation from the same donor. We hypothesized that CHLT reduces the incidence of acute cellular rejection (ACR) and the development of de novo donor-specific antibodies (DSAs) compared with heart-alone transplantation (HA). We conducted a retrospective analysis of 32 CHLT and 280 HA recipients in a single-center experience. The primary outcome was incidence of ACR based on protocol and for-cause myocardial biopsy. Rejection was graded by the International Society of Heart and Lung Transplantation guidelines with Grade 2R and higher considered significant. Secondary outcomes included the development of new DSAs, cardiac function, and patient and cardiac graft survival rates. Of CHLT patients, 9.7% had ACR compared with 45.3% of HA patients (p < 0.01). Mean pretransplant calculated panel reactive antibody (cPRA) levels were similar between groups (CHLT 9.4% vs. HA 9.5%; p = 0.97). Among patients who underwent testing, 26.9% of the CHLT and 16.7% of HA developed DSA (p = 0.19). Despite the difference in ACR, patient and cardiac graft survival rates were similar at 5 years (CHLT 82.1% vs. HA 80.9% [p = 0.73]; CHLT 82.1% vs. HA 80.9% [p = 0.73]). CHLT reduced the incidence of ACR in the cardiac allograft, suggesting that the liver offers immunoprotection against cellular mechanisms of rejection without significant impacts on patient and cardiac graft survival rates. CHLT did not reduce the incidence of de novo DSA, possibly portending similar long-term survival among cardiac allografts in CHLT and HA.

Impact of DSA and immunosuppression minimization on rejection, graft, and patient survival after simultaneous liver–kidney transplantation

Background

Acute rejection rate is low after simultaneous liver–kidney transplantation (SLKT), leading some groups to minimize immunosuppressive (IS) regimens. However, the impact of preformed (pDSA) or de novo donor-specific antibodies (dnDSA) on the graft remains unclear.

Methods

We performed a retrospective analysis of 102 consecutive SLKT patients to study the impact of anti-HLA antibodies.

Results

Anti-HLA antibodies were detected in 75 recipients (class I 23.8%, both classes I and II 23.8%, and class II 14.3%). In total, 42.8% of the patients had pDSA and 21.7% developed dnDSA. Overall patient survival at 1–3 and 5 years, was respectively 88, 84, and 80%. Acute rejection occurred respectively in 3 (2.9%) liver and 6 kidney (5.9%) recipients. pDSA with titers over 10,000 mean fluorescence intensity (14.3%) was associated with lower patient survival (40 vs. 82%) but not with acute rejection. In a multivariable Cox regression analysis, the risk of death was associated with maleness, the highest titer of pDSA (p < 0.0007) or the sum of pDSA >10,000. Renal function did not differ between patients with class I pDSA (p = 0.631) and those with class II pDSA (p = 0.112) or between patients with and without a positive cross-match (p = 0.842). dnDSA were not associated with acute rejection, graft dysfunction or patient survival. IS minimization was not associated with rejection, graft dysfunction or death.

Conclusion

In SLKT, high levels of pDSA >10,000 were associated with lower patient survival, but not rejection or graft survival. Minimization of maintenance immunosuppression regimen was not associated with a poorer outcome.

Renal Function in Receptors With Simultaneous Liver-Kidney Transplant From the Same Donor

Controversy surrounds the suitability of simultaneous liver-kidney transplant (SLKT) when compared with sequential transplant. Pretransplant renal failure is a post-transplant mortality predictor, and studies demonstrate worse functioning and lower survival of the renal graft when compared with kidney transplant alone (KTA).

BACKGROUND

This study compares renal function in patients with SLKT and those who received the contralateral kidney from the same donor.

MATERIAL AND METHODS

From June 2017 to February 2021, 5 SLKTs were performed in our hospital, and contralateral kidney grafts took place in other Andalusian Modification on Diet in Renal Disease-4 hospitals. Renal function was assessed according to glomerular filtration (GF) by the formula (that uses 4 variables: creatinine, age, sex, and race) during different periods of time; and the average increase of GF during 6 months in both groups was compared. Other factors from donors and receptors were also compared.

RESULTS

No statistically significant differences between average GF in both groups were found; however, there were statistically significant differences when we compared the GF increase 6 months after the transplant in both groups of patients, being that increase higher in patients with KTA.

CONCLUSIONS

Despite our small sample size, our study found that patients with SLKT have worse functioning of the kidney graft than those with KTA.

Antibody-mediated rejection of the liver allograft: An update and a clinico-pathological perspective

Antibody-mediated rejection after liver transplantation is an under-recognised cause of allograft injury. While definitions of acute and chronic antibody-mediated rejection have increased clinical awareness, timely identification and management of antibody-mediated rejection remain difficult because of complexities in diagnosis and histopathology, lack of treatment protocols, and unclear long-term outcomes. While recent cohort studies assessing the importance of donor-specific antibodies have aided in its diagnosis, literature on the treatment of antibody-mediated rejection in liver transplantation remain limited to case reports and small series. Further increasing the awareness and timely recognition of antibody-mediated rejection post-liver transplantation is crucial in order to stimulate future research and the development of protocols for its diagnosis and treatment. This review will summarise recent advances in the clinical diagnosis and treatment of antibody-mediated rejection in liver transplantation, as well as some of the histopathologic features (on liver biopsy tissue) of acute and chronic antibody-mediated rejection.

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.

Isolated Liver Rejection After Lung and Combined Kidney-Liver Transplantation: A Case Report

Liver allografts are unique in solid organ transplantation as they are less susceptible to both acute and chronic rejection. Operational tolerance, defined as prolonged graft survival in the absence of immunosuppression, is also achieved more frequently with liver allografts. It is unknown if the presence of multiple allografts in the same individual, levels of immunosuppression, or the presence of cystic fibrosis (CF) impacts the livers ability to ward off rejection or achieve operational tolerance. We describe an unsensitized, ABO-compatible patient with CF who underwent double lung transplantation and several years later a combined liver-kidney transplant. He developed isolated late acute T-cell mediated rejection of his liver allograft despite a high level of immunosuppression (IS) required for his lung and kidney allografts. To our knowledge, this is the first case of isolated liver rejection in a patient with 3 separate organ allografts, or in a patient with CF, to be reported in the literature. This isolated liver rejection is out of keeping with typically accepted ideas about orthotopic liver tolerance.

Strategies for Liver Transplantation Tolerance

Liver transplant (LT) recipients require life-long immunosuppression (IS) therapy to preserve allograft function. The risks of chronic IS include an increased frequency of malignancy, infection, renal impairment, and other systemic toxicities. Despite advances in IS, long-term LT outcomes have not been improved over the past three decades. Standard-of-care (SoC) therapy can, in rare cases, lead to development of operational tolerance that permits safe withdrawal of maintenance IS. However, successful IS withdrawal cannot be reliably predicted and, in current prospective studies, is attempted several years after the transplant procedure, after considerable exposure to the cumulative burden of maintenance therapy. A recent pilot clinical trial in liver tolerance induction demonstrated that peri-transplant immunomodulation, using a regulatory T-cell (Treg) approach, can reduce donor-specific alloreactivity and allow early IS withdrawal. Herein we review protocols for active tolerance induction in liver transplantation, with a focus on identifying tolerogenic cell populations, as well as barriers to tolerance. In addition, we propose the use of novel IS agents to promote immunomodulatory mechanisms favoring tolerance. With numerous IS withdrawal trials underway, improved monitoring and use of novel immunomodulatory strategies will help provide the necessary knowledge to establish an active liver tolerance induction protocol for widespread use.

Optimizing the Selection of Patients for Simultaneous Liver-Kidney Transplant

Simultaneous liver-kidney transplantation has increased significantly in the Model for End Stage Liver Disease era. The transplantation policy has evolved significantly since the implementation of allocation based on the Model for End Stage Liver Disease. Current policy takes into account the medical eligibility criteria for simultaneous liver-kidney transplantation listing. It also provides a safety net option and prioritizes kidney transplant after liver transplant recipients who are unlikely to recover their renal function within 60 to 365 days after liver transplant alone. This review seeks to understand the underlying challenges in carefully selecting the candidates while optimizing the patient selection.

Masked acute rejection of the graft kidney under the recovery of native kidneys in a patient who underwent simultaneous liver and kidney transplantation

INTRODUCTION

Simultaneous liver and kidney transplantation is a life-saving procedure for patients with liver failure and irreversible renal dysfunction. However, some studies have reported the recovery of native renal function after simultaneous liver and kidney transplantation.

CASE PRESENTATION

A 33-year-old woman initially underwent living-donor liver transplantation for liver failure. When graft liver failure developed, she also sustained acute renal failure and required continuous hemodiafiltration for 6 weeks. Simultaneous liver and kidney transplantation from a brain-dead donor recovered her liver and renal function. A 1-year protocol graft kidney biopsy revealed acute cellular rejection despite stable serum creatinine levels. Renal scintigraphy showed functional native kidneys masking acute rejection of the graft kidney. The rejection was improved by pulse steroid therapy.

CONCLUSION

Acute rejection of the graft kidney may silently progress due to recovery of the native kidney function after simultaneous liver and kidney transplantation. Renal scintigraphy and graft kidney biopsy should be considered even if blood tests indicate stable total renal function.

Combined liver and kidney transplantation in children and long-term outcome

Combined liver-kidney transplantation (CLKT) is a rarely performed complex surgical procedure in children and involves transplantation of kidney and either whole or part of liver donated by the same individual (usually a cadaver) to the same recipient during a single surgical procedure. Most common indications for CLKT in children are autosomal recessive polycystic kidney disease and primary hyperoxaluria type 1. Atypical haemolytic uremic syndrome, methylmalonic academia, and conditions where liver and renal failure co-exists may be indications for CLKT. CLKT is often preferred over sequential liver-kidney transplantation due to immunoprotective effects of transplanted liver on renal allograft; however, liver survival has no significant impact. Since CLKT is a major surgical procedure which involves multiple and complex anastomosis surgeries, acute complications are not uncommon. Bleeding, thrombosis, haemodynamic instability, infections, acute cellular rejections, renal and liver dysfunction are acute complications. The long-term outlook is promising with over 80% 5-year survival rates among those children who survive the initial six-month postoperative period.

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.

The Role of Diverse Liver Cells in Liver Transplantation Tolerance

Liver transplantation is the ideal treatment approach for a variety of end-stage liver diseases. However, life-long, systemic immunosuppressive treatment after transplantation is required to prevent rejection and graft loss, which is associated with severe side effects, although liver allograft is considered more tolerogenic. Therefore, understanding the mechanism underlying the unique immunologically privileged liver organ is valuable for transplantation management and autoimmune disease treatment. The unique hepatic acinus anatomy and a complex cellular network constitute the immunosuppressive hepatic microenvironment, which are responsible for the tolerogenic properties of the liver. The hepatic microenvironment contains a variety of hepatic-resident immobile non-professional antigen-presenting cells, including hepatocytes, liver sinusoidal endothelial cells, Kupffer cells, and hepatic stellate cells, that are insufficient to optimally prime T cells locally and lead to the removal of alloreactive T cells due to the low expression of major histocompatibility complex (MHC) molecules, costimulatory molecules and proinflammatory cytokines but a rather high expression of coinhibitory molecules and anti-inflammatory cytokines. Hepatic dendritic cells (DCs) are generally immature and less immunogenic than splenic DCs and are also ineffective in priming naïve allogeneic T cells via the direct recognition pathway in recipient secondary lymphoid organs. Although natural killer cells and natural killer T cells are reportedly associated with liver tolerance, their roles in liver transplantation are multifaceted and need to be further clarified. Under these circumstances, T cells are prone to clonal deletion, clonal anergy and exhaustion, eventually leading to tolerance. Other proposed liver tolerance mechanisms, such as soluble donor MHC class I molecules, passenger leukocytes theory and a high-load antigen effect, have also been addressed. We herein comprehensively review the current evidence implicating the tolerogenic properties of diverse liver cells in liver transplantation tolerance.

Kidney Rejection Following Simultaneous Liver-kidney Transplantation

Background.

Donor-specific antibodies are reported to increase the risk of rejection and reduce allograft survival following simultaneous liver-kidney transplantation. Optimal immunosuppression regimens to reduce this risk and to treat rejection episodes are underinvestigated.

Methods.

Cohort analysis of the first 27 simultaneous liver-kidney transplant recipients, between 2014 and 2018 at our unit, is performed under a new risk stratification policy. Those with donor-specific antibodies to class II HLA with a mean fluorescence intensity >10 000 are considered high risk for antibody-mediated rejection (AMR). These patients received immunosuppression, which consisted of induction therapy, tacrolimus, mycophenolate mofetil, and prednisolone. All other patients are considered low risk and received tacrolimus and prednisolone alone.

Results.

Three patients were high risk for rejection, and 2 of these patients developed AMR, which was treated with plasma exchange and intravenous immunoglobulin. At 1 y, their estimated glomerular filtration rate (eGFR) were 50 and 59 mL/min. Two other patients developed AMR, which was similarly treated, and their 1-y eGFR was 31 and 50 mL/min. The overall histologically proven acute rejection rate within the first year was 33%, and median eGFR, for the 27 patients, at 1 y was 52 mL/min and at 2 y was 49 mL/min.

Conclusions.

This study confirms that there is a risk of AMR following simultaneous liver-kidney transplantation despite increased immunosuppression. This can be effectively treated with plasma exchange and intravenous immunoglobulin.

Deletion of donor-reactive T cell clones after human liver transplant

We recently developed a high throughput T cell receptor β chain (TCRβ) sequencing-based approach to identifying and tracking donor-reactive T cells. To address the role of clonal deletion in liver allograft tolerance, we applied this method in samples from a recent randomized study, ITN030ST, in which immunosuppression withdrawal was attempted within 2 years of liver transplantation. We identified donor-reactive T cell clones via TCRβ sequencing following a pre-transplant mixed lymphocyte reaction and tracked these clones in the circulation following transplantation in 3 tolerant and 5 non-tolerant subjects. All subjects showed a downward trend and significant reductions in donor-reactive TCRβ sequences were detected post-transplant in 6 of 8 subjects, including 2 tolerant and 4 non-tolerant recipients. Reductions in donor-reactive TCRβ sequences were greater than those of all other TCRβ sequences, including 3rd party-reactive sequences, in all 8 subjects, demonstrating an impact of the liver allograft after accounting for repertoire turnover. Although limited by patient number and heterogeneity, our results suggest that partial deletion of donor-reactive T cell clones may be a consequence of liver transplantation and does not correlate with success or failure of early immunosuppression withdrawal. These observations underscore the organ- and/or protocol-specific nature of tolerance mechanisms in humans.

Liver Transplantation

The field of liver transplantation has changed since the MELD scoring system became the most widely used donor allocation tool. Due to the MELD-based allocation system, sicker patients with higher MELD scores are being transplanted. Persistent organ donor shortages remain a challenging issue, and as a result, the wait-list mortality is a persistent problem for most of the regions. This chapter focuses on deceased donor and live donor liver transplantation in patients with complications of portal hypertension. Special attention will also be placed on donor-recipient matching, perioperative management of transplant patients, and the impact of hepatic hemodynamics on transplantation.

Revisiting the liver’s role in transplant alloimmunity

The transplanted liver can modulate the recipient immune system to induce tolerance after transplantation. This phenomenon was observed nearly five decades ago. Subsequently, the liver’s role in multivisceral transplantation was recognized, as it has a protective role in preventing rejection of simultaneously transplanted solid organs such as kidney and heart. The liver has a unique architecture and is home to many cells involved in immunity and inflammation. After transplantation, these cells migrate from the liver into the recipient. Early studies identified chimerism as an important mechanism by which the liver modulates the human immune system. Recent studies on human T-cell subtypes, cytokine expression, and gene expression in the allograft have expanded our knowledge on the potential mechanisms underlying immunomodulation. In this article, we discuss the privileged state of liver transplantation compared to other solid organ transplantation, the liver allograft’s role in multivisceral transplantation, various cells in the liver involved in immune responses, and the potential mechanisms underlying immunomodulation of host alloresponses.

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.

Lack of Benefit and Potential Harm of Induction Therapy in Simultaneous Liver-Kidney Transplants

The number of simultaneous liver-kidney transplantations (SLKTs) and use of induction therapy for SLKT have increased recently, without much published evidence, especially in the context of maintenance immunosuppression containing tacrolimus (TAC) and mycophenolic acid (MPA). We queried the Organ Procurement and Transplant Network registry for SLKT recipients maintained on TAC/MPA at discharge in the United States for 2002-2016. The cohort was divided into 3 groups on the basis of induction type: rabbit antithymocyte globulin (r-ATG; n = 831), interleukin 2 receptor antagonist (IL2RA; n = 1558), and no induction (n = 2333). Primary outcomes were posttransplant all-cause mortality and acute rejection rates in kidney and liver allografts at 12 months. Survival rates were analyzed by the Kaplan-Meier method. A propensity score analysis was used to control potential selection bias. Multivariate inverse probability weighted Cox proportional hazard and logistic regression models were used to estimate the hazard ratios (HRs) and odds ratios. Among SLKT recipients, survival estimates at 3 years were lower for recipients receiving r-ATG (P = 0.05). Compared with no induction, the multivariate analyses showed an increased mortality risk with r-ATG (HR, 1.29; 95% confidence interval [CI], 1.10-1.52; P = 0.002) and no difference in acute liver or kidney rejection rates at 12 months across all induction categories. No difference in outcomes was noted with IL2RA induction over the no induction category. In conclusion, there appears to be no survival benefit nor reduction in rejection rates for SLKT recipients who receive induction therapy, and r-ATG appears to increase mortality risk compared with no induction.

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.

Simultaneous Versus Sequential Heart-liver Transplantation: Ideal Strategies for Organ Allocation

Background

Simultaneous heart-liver (SHL) transplantation is an efficacious therapeutic modality for patients with combined heart and liver failure. However, the extent to which heart transplantation followed by sequential liver transplantation (LAH) can match the benefit of simultaneous transplantation has not previously been examined. Our objective was to determine if LAH offers comparable survival to SHL.

Methods

The Organ Procurement and Transplantation Network/United Network for Organ Sharing Standard Transplant Analysis and Research file was queried for adult recipients waitlisted for both heart and liver transplantation. The United Network for Organ Sharing thoracic and liver databases were linked to facilitate examination of waitlist and transplant characteristics for simultaneously listed patients. Univariate survival analysis was used to determine overall survival.

Results

Of the 236 patients meeting inclusion criteria, 200 underwent SHL, 7 sequentially underwent LAH, and 29 received heart transplantation only (isolated orthotopic heart transplantation [iOHT]). Recipients of SHL were less likely to have an episode of acute rejection before discharge (LAH, 14.2%; SHL, 2.4%; iOHT, 3.6%; P = .019) or be treated for acute rejection within 1 year after transplantation (LAH, 14.3%; SHL, 2.5%; iOHT, 13.8%; P = .007). Otherwise, postoperative hospital length of stay, stroke, need for dialysis, and need for pacemaker placement were comparable across groups. Ten-year survival similarly favored both LAH and SHL over iOHT (LAH: 100%, 71.4%, 53.6%; SHL: 87.1%, 80.4%, 52.1%, iOHT: 70.1%, 51.6%, 27.5% for 1-, 5-, and 10-year survivals, respectively, P = .003). However, median time between heart and liver transplant was 302 days in patients undergoing sequential transplantation.

Conclusions

Although transplantation in a simultaneous or sequential fashion yields equivalent outcomes, a high fraction of patients undergoing initial heart transplant alone fail to proceed to subsequent liver transplantation. Therefore, in patients with combined heart and liver failure with a projected need for 2 allografts, simultaneous transplantation is associated with maximum benefit.

Successful long-term outcome of pediatric liver-kidney transplantation: a single-center study

INTRODUCTION

Liver-kidney transplantation is a rare procedure in children, with just ten to 30 cases performed annually worldwide. The main indications are autosomal recessive polycystic liver-kidney disease and primary hyperoxaluria. This study aimed to report outcomes of liver-kidney transplantation in a cohort of pediatric patients.

METHODS

We retrospectively analyzed all pediatric liver-kidney transplantations performed in our center between September 2000 and August 2015. Patient data were obtained by reviewing inpatient and outpatient medical records and our transplant database.

RESULTS

A total of 14 liver-kidney transplants were performed during the study period, with a median patient age and weight at transplant of 144.4 months (131.0-147.7) and 27.3 kg (12.0-45.1), respectively. The indications for liver-kidney transplants were autosomal recessive polycystic liver-kidney disease (8/14), primary hyperoxaluria -1 (5/14), and idiopathic portal hypertension with end-stage renal disease (1/14). Median time on waiting list was 8.5 months (5.7-17.3). All but two liver-kidney transplants were performed simultaneously. Patients with primary hyperoxaluria-1 tended to present a delayed recovery of renal function compared with patients transplanted for other indications (62.5 vs 6.5 days, respectively, P 0.076). Patients with liver-kidney transplants tended to present a lower risk of acute kidney rejection than patients transplanted with an isolated kidney transplant (7.2% vs 32.7%, respectively; P < 0.07). Patient and graft survival at 1, 3, and 5 years were 100%, 91.7%, 91.7%, and 91.7%, 83.3%, 83.3%, respectively. No other grafts were lost.

CONCLUSION

Long-term results of liver-kidney transplants in children are encouraging, being comparable with those obtained in isolated liver transplantation.

Utility in Treating Kidney Failure in End-Stage Liver Disease With Simultaneous Liver-Kidney Transplantation

Background

Simultaneous liver-kidney (SLK) transplantation plays an important role in treating kidney failure in patients with end-stage liver disease. It used 5% of deceased donor kidney transplanted in 2015. We evaluated the utility, defined as posttransplant kidney allograft lifespan, of this practice.

Methods

Using data from the Scientific Registry of Transplant Recipients, we compared outcomes for all SLK transplants between January 1, 1995, and December 3, 2014, to their donor-matched kidney used in kidney-alone (Ki) or simultaneous pancreas kidney (SPK) transplants. Primary outcome was kidney allograft lifespan, defined as the time free from death or allograft failure. Secondary outcomes included death and death-censored allograft failure. We adjusted all analyses for donor, transplant, and recipient factors.

Results

The adjusted 10-year mean kidney allograft lifespan was higher in Ki/SPK compared with SLK transplants by 0.99 years in the Model for End-stage Liver Disease era and 1.71 years in the pre-Model for End-stage Liver Disease era. Death was higher in SLK recipients relative to Ki/SPK recipients: 10-year cumulative incidences 0.36 (95% confident interval 0.33-0.38) versus 0.19 (95% confident interval 0.17-0.21).

Conclusions

SLK transplantation exemplifies the trade-off between the principles of utility and medical urgency. With each SLK transplantation, about 1 year of allograft lifespan is traded so that sicker patients, that is, SLK transplant recipients, are afforded access to the organ. These data provide a basis against which benefits derived from urgency-based allocation can be measured.

This analysis of the UNOS data demonstrated that SLK patients had decreased long term renal graft function that SPK patients. This analysis demonstrates the difficult policy choices epitomized by prioritizing the SLK population and its impact of utility considerations. Supplemental digital content is available in the text.

Avoiding Futility in Simultaneous Liver-kidney Transplantation: Analysis of 331 Consecutive Patients Listed for Dual Organ Replacement

OBJECTIVE

We sought to evaluate outcomes and predictors of renal allograft futility (RAF-patient death or need for renal replacement therapy at 3 months) after simultaneous liver-kidney transplantation (SLKT).

BACKGROUND

Model for End-Stage Liver Disease (MELD) prioritization of liver recipients with renal dysfunction has significantly increased utilization of SLKT. Data on renal outcomes after SLKT in the highest MELD recipients are scarce, as are accurate predictors of recovery of native kidney function. Without well-established listing guidelines, SLKT potentially wastes renal allografts in both high-acuity liver recipients at risk for early mortality and recipients who may regain native kidney function.

METHODS

A retrospective single-center multivariate regression analysis was performed for adult patients undergoing SLKT (January 2004 to August 2014) to identify predictors of RAF.

RESULTS

Of 331 patients dual-listed for SLKT, 171 (52%) expired awaiting transplant, 145 (44%) underwent SLKT, and 15 (5%) underwent liver transplantation alone. After SLKT, 39% experienced delayed graft function and 20.7% had RAF. Compared with patients without RAF, RAF recipients had greater MELD scores, length of hospitalization, intraoperative base deficit, incidence of female donors, kidney and liver donor risk indices, kidney cold ischemia, and inferior overall survival. Multivariate predictors of RAF included pretransplant dialysis duration, kidney cold ischemia, kidney donor risk index, and recipient hyperlipidemia.

CONCLUSIONS

With 20% short-term loss of transplanted kidneys after SLKT, our data strongly suggest that renal transplantation should be deferred in liver recipients at high risk for RAF. Consideration for a kidney allocation variance to allow for delayed renal transplantation after liver transplantation may prevent loss of scarce renal allografts.

Liver Allograft Provides Immunoprotection for the Cardiac Allograft in Combined Heart-Liver Transplantation

When transplanted simultaneously, the liver allograft has been thought to have an immunoprotective role on other organs; however, detailed analyses in simultaneous heart-liver transplantation (SHLT) have not been done to date. We analyzed patient outcomes and incidence of immune-mediated injury in 22 consecutive SHLT versus 223 isolated heart transplantation (IHT) recipients between January 2004 and December 2013, by reviewing 3912 protocol- and indication-specific cardiac allograft biopsy specimens. Overall survival was similar (86.4%, 86.4%, and 69.1% for SHLT and 93.3%, 84.7%, and 70.0% for IHT at 1, 5, and 10 years; p = 0.83). Despite similar immunosuppression, the incidence of T cell-mediated rejection (TCMR) was lower in SHLT (31.8%) than in IHT (84.8%) (p < 0.0001). Although more SHLT patients had preexisting donor-specific HLA antibody (22.7% versus 8.1%; p = 0.04), the incidence of antibody-mediated rejection was not different in SHLT compared with IHT (4.5% versus 14.8%, p = 0.33). While the left ventricular ejection fraction was comparable in both groups at 5 years, the incidence and severity of cardiac allograft vasculopathy were reduced in the SHLT recipients (42.9% versus 66.8%, p = 0.03). Simultaneously transplanted liver allograft was associated with reduced risk of TCMR (odds ratio [OR] 0.003, 95% confidence interval [CI] 0-0.02; p < 0.0001), antibody-mediated rejection (OR 0.04, 95% CI 0-0.46; p = 0.004), and cardiac allograft vasculopathy (OR 0.26, 95% CI 0.07-0.84; p = 0.02), after adjusting for other risk factors. These data suggest that the incidence of alloimmune injury in the heart allograft is reduced in SHLT recipients.

The CD8 T-cell response during tolerance induction in liver transplantation

Both experimental and clinical studies have shown that the liver possesses unique tolerogenic properties. Liver allografts can be spontaneously accepted across complete major histocompatibility mismatch in some animal models. In addition, some liver transplant patients can be successfully withdrawn from immunosuppressive medications, developing ‘operational tolerance'. Multiple mechanisms have been shown to be involved in inducing and maintaining alloimmune tolerance associated with liver transplantation. Here, we focus on CD8 T-cell tolerance in this setting. We first discuss how alloreactive cytotoxic T-cell responses are generated against allografts, before reviewing how the liver parenchyma, donor passenger leucocytes and the host immune system function together to attenuate alloreactive CD8 T-cell responses to promote the long-term survival of liver transplants.

[Polycystic kidney disease and kidney transplantation]

OBJECTIVES

To perform a state of the art about autosomal dominant polykystic kidney disease (ADPKD), management of its urological complications and end stage renal disease treatment modalities.

MATERIAL AND METHODS

An exhaustive systematic review of the scientific literature was performed in the Medline database (http://www.ncbi.nlm.nih.gov) and Embase (http://www.embase.com) using different associations of the following keywords (MESH): "autosomal dominant polykystic kidney disease", "complications", "native nephrectomy", "kidney transplantation". Publications obtained were selected based on methodology, language, date of publication (last 10 years) and relevance. Prospective and retrospective studies, in English or French, review articles; meta-analysis and guidelines were selected and analyzed. This search found 3779 articles. After reading titles and abstracts, 52 were included in the text, based on their relevance.

RESULTS

ADPKD is the most inherited renal disease, leading to end stage renal disease requiring dialysis or renal transplantation in about 50% of the patients. Many urological complications (gross hematuria, cysts infection, renal pain, lithiasis) of ADPKD required urological management. The pretransplant evaluation will ask the challenging question of native nephrectomy only in case of recurrent kidney complications or large kidney not allowing graft implantation. The optimum timing for native nephrectomy will depend on many factors (dialysis or preemptive transplantation, complication severity, anuria, easy access to transplantation, potential living donor).

CONCLUSION

Pretransplant management of ADPKD is challenging. A conservative strategy should be promoted to avoid anuria (and its metabolic complications) and to preserve a functioning low urinary tract and quality of life. When native nephrectomy should be performed, surgery remains the gold standard but renal arterial embolization may be a safe option due to its low morbidity.

Sequential kidney-liver transplantation from the same living donor for lecithin cholesterol acyl transferase deficiency

BACKGROUND

Lecithin cholesterol acyl transferase (LCAT) deficiency is a rare autosomal recessive disorder of lipoprotein metabolism that results in end-stage renal disease (ESRD) necessitating transplantation. As LCAT is produced in the liver, combined kidney and liver transplantation was proposed to cure the clinical syndrome of LCAT deficiency.

METHODS

A 29-year-old male with ESRD secondary to LCAT deficiency underwent a sequential kidney-liver transplantation from the same living donor (LD). One year following the kidney transplant, auxiliary partial orthotopic liver transplant (APOLT) of a left lateral segment from the same donor was performed.

RESULTS

At 5 years follow-up, there have been no major complications, readmissions, or rejection episodes. Serum lipid abnormalities recurred within the first year, but liver and kidney allograft function remains intact.

CONCLUSION

Few cases of sequential transplantation from the same LD have been performed in adults. This is the first APOLT and multi-organ transplant performed for LCAT deficiency. Sequential organ transplant from the same LD for ESRD secondary to a metabolic disorder of the liver is feasible in adults and should be further investigated.

Combined liver and kidney transplantation in children: analysis of renal graft outcome

BACKGROUND

Combined liver-kidney transplantation (CLKT) is the accepted treatment for patients with both liver failure and progressive renal insufficiency. Long-term outcome data for CLKT in children is sparse and controversy exists as to whether simultaneous CLKT with organs from the same donor confers immunologic and survival benefit to the kidney allograft. We report the long-term renal graft outcomes of 40 patients who had simultaneous CLKT.

METHODS

A retrospective analysis of kidney graft survival (time from transplantation to death, return to dialysis or last follow-up event) in all pediatric patients (age < 18 years old) who underwent CLKT from March 1994 to January 2015. A 1:1 ratio of controls (deceased donor kidney recipients from our centre matched for age (±2 years) at transplant, time from transplant (±1 year) and treated with the same immunosuppressive regime) to cases was used to compare outcome. Estimated glomerular filtration rate (e-GFR) was calculated using the Schwartz formula. Survival curves were determined using Kaplan-Meier analysis.

RESULTS

The kidney graft survival for CLKT patients was 87.4, 82, and 82 % at 1, 5, and 10 years; kidney graft survival for isolated KT patients were 97.2, 93, and 93 % at 1, 5, and 10 years (p = NS). There were two acute rejection episodes (5 %) in the CLKT group compared to five (12.5 %) episodes in the isolated KT group. There was no statistically significant difference in e-GFR at 1, 5, and 10 years in the two groups but there was a statistically significantly greater decline in e-GFR in the KT group compared to CLKT group from 5-10 years following transplant.

CONCLUSIONS

There are fewer acute rejection episodes following CLKT compared to isolated KT, and we noted a higher mean e-GFR at 1, 5, and 10 years with significantly lesser decline in e-GFR from 5 to 10 years in the CLKT group.

Kidney transplantation after liver transplantation

Kidney transplantation after liver transplantation (KALT) offers longer survival and a better quality of life to liver transplantation recipients who develop chronic renal failure. This article aimed to discuss the efficacy and safety of KALT compared with other treatments. The medical records of 5 patients who had undergone KALT were retrospectively studied, together with a literature review of studies. Three of them developed chronic renal failure after liver transplantation because of calcineurin inhibitor (CNI)-induced nephrotoxicity, while the others had lupus nephritis or non-CNI drug-induced nephrotoxicity. No mortality was observed in the 5 patients. Three KALT cases showed good prognoses, maintaining a normal serum creatinine level during entire follow-up period. Chronic rejection occurred in the other two patients, and a kidney graft was removed from one of them. Our data suggested that KALT is a good alternative to dialysis for liver transplantation recipients. The cases also indicate that KALT can be performed with good long-term survival.

Peripheral phenotype and gene expression profiles of combined liver-kidney transplant patients

BACKGROUND AND AIMS

The beneficial effect of one graft on another has been reported in combined transplantation but the associated mechanisms and biological influence of each graft have not yet been established.

METHODS

In multiple analyses, we explored the PBMC phenotype and signature of 45 immune-related messenger RNAs and 754 microRNAs from a total of 235 patients, including combined liver-kidney transplant recipients (CLK), patients with a liver (L-STA) or kidney (K-STA) graft only under classical immunosuppression and patients with tolerated liver (L-TOL) or kidney grafts (K-TOL).

RESULTS

CLK show an intermediary phenotype with a higher percentage of peripheral CD19(+) CD24(+) CD38(Low) memory B cells and Helios(+) Treg cells, two features associated with tolerance profiles, compared to L-STA and K-STA (P < 0.05, P < 0.01). Very few miRNA were significantly differentially expressed in CLK vs. K-STA and even fewer when compared to L-STA (35 and 8, P < 0.05). Finally, CLK are predicted to share common miRNA targets with K-TOL and even more with L-TOL (344 and 411, P = 0.005). Altogether CLK display an intermediary phenotype and gene profile, which is closer to that of liver transplant patients, with possible similarities with the profiles of tolerant patients.

CONCLUSION

These data suggest that CLK patients show the immunological influence of both allografts with liver having a greater influence.

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.

Renal transplantation in autosomal dominant polycystic kidney disease

In patients with autosomal dominant polycystic kidney disease (ADPKD) evaluated for kidney transplantation, issues related to native nephrectomy, cystic liver involvement, screening for intracranial aneurysms and living-related kidney donation deserve special consideration. Prophylactic native nephrectomy is restricted to patients with a history of cyst infection or recurrent haemorrhage or to those in whom space must be made to implant the graft. Patients with liver involvement require pretransplant imaging. Selection of patients for pretransplant screening of intracranial aneurysms should follow the general recommendations for patients with ADPKD. In living related-donor candidates aged <30 years and at-risk of ADPKD, molecular genetic testing should be carried out when ultrasonography and MRI findings are normal or equivocal. After kidney transplantation, patient and graft survival rates are excellent and the volume of native kidneys decreases. However, liver cysts continue to grow and treatment with a somatostatin analogue should be considered in patients with massive cyst involvement. Cerebrovascular events have a marginal effect on post-transplant morbidity and mortality. An increased risk of new-onset diabetes mellitus and nonmelanoma skin cancers has been reported, but several studies have challenged these findings. Finally, no data currently support the preferential use of mammalian target of rapamycin inhibitors as immunosuppressive agents in transplant recipients with ADPKD.

Combined liver and kidney transplantation in children

Simultaneous combined liver-kidney transplantation (CLKT) is a rare operation in pediatric patients so that annually only 10-30 operations are performed worldwide. The main indications for CLKT are primary hyperoxaluria type 1 and autosomal recessive polycystic kidney disease. In addition, CLKT is indicated in individual patients with metabolic or cirrhotic liver diseases and end-stage kidney disease. The surgery and immediate post-operative management of CLKT remain challenging in infants and small children. The patients should be operated on before they become severely ill or develop major systemic manifestations of their metabolic disorder. The liver allograft is immunologically protective of the kidney graft in simultaneous CLKT, often resulting in well-preserved kidney function. The long-term outcome after CLKT is nowadays comparable to that of isolated liver and kidney transplantations.

Liver transplant tolerance and its application to the clinic: can we exploit the high dose effect?

The tolerogenic properties of the liver have long been recognised, especially in regard to transplantation. Spontaneous acceptance of liver grafts occurs in a number of experimental models and also in a proportion of clinical transplant recipients. Liver graft acceptance results from donor antigen-specific tolerance, demonstrated by the extension of tolerance to other grafts of donor origin. A number of factors have been proposed to be involved in liver transplant tolerance induction, including the release of soluble major histocompatibility (MHC) molecules from the liver, its complement of immunosuppressive donor leucocytes, and the ability of hepatocytes to directly interact with and destroy antigen-specific T cells. The large tissue mass of the liver has also been suggested to act as a cytokine sink, with the potential to exhaust the immune response. In this review, we outline the growing body of evidence, from experimental models and clinical transplantation, which supports a role for large tissue mass and high antigen dose in the induction of tolerance. We also discuss a novel gene therapy approach to exploit this dose effect and induce antigen-specific tolerance robust enough to overcome a primed T cell memory response.

Predisposing factors of diminished survival in simultaneous liver/kidney transplantation

Since the adoption of the Model for End-Stage Liver Disease, simultaneous liver/kidney transplants (SLKT) have substantially increased. Recently, unfavorable outcomes have been reported yet contributing factors remain unclear. We retrospectively reviewed 74 consecutive adult SLKT performed at our center from 2000 to 2010 and compared with kidney transplant alone (KTA, N = 544). In SLKT, patient and death-censored kidney graft survival rates were 64 ± 6% and 81 ± 5% at 5 years, respectively (median follow-up, 47 months). Multivariable analyses revealed three independent risk factors affecting patient survival: hepatitis C virus positive (HCV+, hazard ratio [HR] 2.9, 95% confidence interval [CI] 1.1-7.9), panel reactive antibody (PRA) > 20% (HR 2.8, 95% CI 1.1-7.2) and female donor gender (HR 2.9, 95% CI 1.1-7.9). For death-censored kidney graft survival, delayed graft function was the strongest negative predictor (HR 8.3, 95% CI 2.5-27.9), followed by HCV+ and PRA > 20%. The adjusted risk of death-censored kidney graft loss in HCV+ SLKT patients was 5.8 (95% CI 1.6-21.6) compared with HCV+ KTA (p = 0.008). Recurrent HCV within 1 year after SLKT correlated with early kidney graft failure (p = 0.004). Careful donor/recipient selection and innovative approaches for HCV+ SLKT patients are critical to further improve long-term outcomes.

Combined liver-kidney transplantation is preferable to liver transplant alone for cirrhotic patients with renal failure

BACKGROUND

The role of combined liver-kidney transplantation (CLKT) for cirrhotic patients with renal failure (RF) is controversial. Since the model for end-stage liver disease era, there has been a rise in the number of CLKT. Using the Organ Procurement Transplant Network/United Network for Organ Sharing database, this study was undertaken to compare outcomes of cirrhotic patients with RF who received either liver transplant alone (LTA) or CLKT between 2002 and 2008.

METHODS

Analysis was limited to cirrhotic patients 18 years old or older, with serum creatinine level 2.5 mg/dL or higher at the time of orthotopic liver transplantation (OLT) or who received dialysis at least twice during the week before OLT. Patients who received CLKT were categorized based on the cause of their underlying RF.

RESULTS

Overall liver allograft and patient survival rates of LTA patients were significantly lower compared with CLKT patients (P<0.001). CLKT patients with hepatorenal syndrome showed significantly higher patient and liver allograft survival rates. Liver allograft survival was superior among CLKT patients irrespective of whether they received dialysis. Prevalence of posttransplantation RF was higher for LTA patients at 6 months and 3 years of follow-up (P<0.001). LTA was a significant risk factor both for graft loss and mortality. Recipient hepatitis C virus seropositivity, donor age, donor cause of death, and life support at the time of OLT were also risk factors for graft loss and death.

CONCLUSIONS

Cirrhotic patients with RF, in particular with hepatorenal syndrome, CLKT is preferable to LTA because it improves liver allograft and patient survival.

Recipient survival and graft survival are not diminished by simultaneous liver-kidney transplantation: an analysis of the united network for organ sharing database

Recipients of solitary liver and kidney transplants are living longer, and this increases their risk of long-term complications such as recurrent hepatitis C virus (HCV) and drug-induced nephrotoxicity. These complications may require retransplantation. Since the adoption of the Model for End-Stage Liver Disease, the number of simultaneous liver-kidney transplantation (SLK) procedures has increased. However, there are no standardized criteria for organ allocation to SLK candidates. The aims of this study were to retrospectively compare recipient and graft survival with liver transplantation alone (LTA), SLK, kidney after liver transplantation (KALT), and liver after kidney transplantation (LAKT) and to identify independent risk factors affecting recipient and graft survival. The United Network for Organ Sharing/Organ Procurement and Transplantation Network database (1988-2007) was queried for adult LTA (66,026), SLK (2327), KALT (1738), and LAKT procedures (242). After adjustments for potential confounding demographic and clinical variables, there was no difference in recipient mortality rates with LTA and SLK (P = 0.02). However, there was a 15% decreased risk of graft loss with SLK versus LTA (hazard ratio = 0.85, P < 0.001). The recipient and graft survival rates with SLK were higher than the rates with both KALT (P <0.001 and P <0.001) and LAKT (P = 0.003 and P < 0.001). The following were all identified as independent negative predictors of recipient mortality and graft loss: recipient age ≥ 65 years, male sex, black race, HCV/diabetes mellitus status, donor age ≥ 60 years, serum creatinine level ≥2.0 mg/dL, cold ischemia time > 12 hours, and warm ischemia time > 60 minutes. Although the recent increase in the number of SLK procedures performed each year has effectively decreased the number of potential donor kidneys available to patients with end-stage renal disease (ESRD) awaiting kidney transplantation, SLK in patients with end-stage liver disease and ESRD is justified because of the lower risk of graft loss with SLK versus LTA as well as the superior recipient and graft survival with SLK versus serial liver-kidney transplantation.

Management of hemolytic uremic syndrome

2011 has been a special year for hemolytic uremic syndrome (HUS): on the one hand, the dramatic epidemic of Shiga toxin producing E. coli -associated HUS in Germany brought the disease to the attention of the general population, on the other hand it has been the year when eculizumab, the first complement blocker available for clinical practice, was demonstrated as the potential new standard of care for atypical HUS. Here we review the therapeutic options presently available for the various forms of hemolytic uremic syndrome and show how recent knowledge has changed the therapeutic approach and prognosis of atypical HUS.