Domino liver transplantation in maple syrup urine disease

Living Donor Whole and Partial Liver Grafts, Deceased Donor Whole Liver and SPLIT: Outcome Comparison

BACKGROUND

Currently, graft options for pediatric liver transplantation (PLT) include whole (WL) and partial (P) grafts, in the form of either deceased donor transplantation (DD) or living donor liver transplantation (LD). WL transplants from LD are commonly referred to as domino LT. The objective of this manuscript is to compare the outcomes of PLT performed with each of the available graft options.

METHODS

Retrospective cohort study from Jan. 2010 to Dec. 2022. The variables included data on the recipients' preoperative clinical status, intraoperative technical aspects, post-operative complications, and survival studies. There were 4 groups: SPLIT (17), DD-WL (55), LD-WL (824), and LD-P (22).

RESULTS

The median age and BW of the recipients was smaller in SPLIT, LD-P, and LD-WL compared to DDT-WL groups. HVOO (HR 15.87, 95% CI 1.89-133.06, P = 0.01), retransplantation (HR 7.94, 95% CI 2.63-24.02, P < 0.01), and malignancies (HR 3.08, 95% CI 1.29-7.37, P = 0.01) were independently associated with decreased patient survival. HAT (HR 27.54, 95% CI 10.44-72.68, P < 0.01) and malignancies (HR 2.42, 95% CI 1.10-5.34, P = 0.03) increased the risk of graft loss. The overall survival in this series was 91.4% (mean follow-up of 74.3 months). Patient and graft survival were not different among groups.

CONCLUSION

HAT and malignancies were associated with reduced graft survival. Whole liver from living donors with MSUD presented 100% patient survival at 120 months. Even without statistical differences in survival among the studied groups, LD-P and LD-WL recipients presented a trend towards better outcomes.

LEVEL OF EVIDENCE

LEVEL III.

Perioperative management in pediatric domino liver transplantation for metabolic disorders: A narrative review

Domino liver transplantation and domino-auxiliary partial orthotopic liver transplantation are emerging techniques that can expand the liver donor pool and provide hope for children with liver disease. The innovative technique of domino liver transplantation has emerged as a pioneering strategy, capitalizing on structurally preserved livers from donors exhibiting single enzymatic defects within a morphologically normal context, effectively broadening the donor pool. Concurrently, the increasingly prevalent domino-auxiliary partial orthotopic liver transplantation method assumes a critical role in bolstering available donor resources. These advanced transplantation methods present a unique opportunity for pediatric patients who, despite having structurally and functionally intact livers and lacking early signs of portal hypertension or extrahepatic involvement, do not attain priority on conventional transplant lists. Utilizing optimal clinical conditions enhances posttransplant outcomes, benefiting patients who would otherwise endure extended waiting periods for traditional transplantation. The perioperative management of children undergoing these procedures is complex and requires careful consideration of some factors, including clinical and metabolic conditions of the specific metabolic disorder, and the need for tailored perioperative management planning. Furthermore, the prudent consideration of de novo disease development in the recipient assumes paramount significance when selecting suitable donors for domino liver transplantation, as it profoundly influences prognosis, mortality, and morbidity. This narrative review of domino liver transplantation will discuss the pathophysiology, clinical evaluation, perioperative management, and prognostic expectations, focusing on perioperative anesthetic considerations for children undergoing domino liver transplantation.

Current status and future directions of liver transplantation for metabolic liver disease in children

Orthotopic liver transplantation (OLT) in the care of children with inborn errors of metabolism (IEM) is well established and represent the second most common indication for pediatric liver transplantation in most centers worldwide, behind biliary atresia. OLT offers cure of disease when a metabolic defect is confined to the liver, but may still be transformative on a patient's quality of life reducing the chance of metabolic crises causing neurological damage in children be with extrahepatic involvement and no "functional cure." Outcomes post-OLT for inborn errors of metabolism are generally excellent. However, this benefit must be balanced with consideration of a composite risk of morbidity, and commitment to a lifetime of post-transplant chronic disease management. An increasing number of transplant referrals for children with IEM has contributed to strain on graft access in many parts of the world. Pragmatic evaluation of IEM referrals is essential, particularly pertinent in cases where progression of extra-hepatic disease is anticipated, with long-term outcome expected to be poor. Decision to proceed with liver transplantation is highly individualized based on the child's dynamic risk-benefit profile, their family unit, and their treating multidisciplinary team. Also to be considered is the chance of future treatments, such as gene therapies, emerging in the medium term.

Domino liver transplantation for maple syrup urine disease in children: A single-center case series

BACKGROUND

Domino liver transplant (DLT) represents another type of liver donor to expand the donor pool. Recent reports of successful DLT in children with maple syrup urine disease (MSUD) show promising long-term outcomes.

METHODS

It was a retrospective study. All children with MSUD were paired with either recipients with end-stage liver disease (ESLD) or non-MSUD metabolic disease. Each pair underwent simultaneous liver transplant (LT), where the MSUD recipient received the graft from a living-related donor and the liver explanted from the MSUD donor was transplanted to the respective paired domino recipient. We report our experience regarding the techniques and outcomes of DLT at our center.

RESULTS

Eleven children with MSUD and 12 respective DLT recipients were enrolled, one of which was domino split-liver transplantation. DLT recipients included seven ESLD, two propionic acidemia (PA), one glycogen storage disease(GSD) type-1, one GSD type-3, and one Citrullinemia. Post-LT ICU and hospital stays were comparable (p > .05). Patient and graft survival was 100% and 66.6% in the MSUD group and DLT recipients at a mean follow-up of 13.5 and 15 months. There was no death in the MSUD group as compared to four in the DLT group. The amino acid levels rapidly normalized after the LT in the children with MSUD and they tolerated the normal unrestricted diet. No vascular, biliary, or graft-related complications were seen in the post-transplant period. No occurrence of MSUD was noted in DLT recipients.

CONCLUSION

DLTs have excellent post-surgical outcomes. DLT should be strongly considered and adopted by transplant programs worldwide to circumvent organ shortage.

Domino liver transplants: where do we stand after a quarter-century? A US national analysis

BACKGROUND

Domino liver transplantation (DLT) utilizes a phenotypically normal explant from select recipients as a donor graft in another patient. The procedure is not widely employed and remains restricted to a small number of centers. The purpose of this study was to assess the national profile of DLT in the United States (US) and evaluate current survival outcomes.

METHODS

The United Network for Organ Sharing (UNOS) database was queried for all liver transplants (LT) between 1996 and 2020. Outcomes of interest were long-term graft and patient survival.

RESULTS

Of 181,976 LTs performed nationally during the study period, 185 (0.1%) were DLTs. Amyloidosis and maple syrup urine disease (MSUD) accounted for 83% of dominoed allografts. Out of 210 explants with amyloidosis, 103 (49%) were dominoed into secondary recipients. Only 50 (22%) of all MSUD explants (n = 227) were dominoed. Graft survival was 79%, 73% and 53% at 3-, 5- and 10-years, respectively, for DLT recipients. Overall patient survival was 83%, 76% and 57% at 3-, 5- and 10-years.

CONCLUSION

Despite excellent long-term survival outcomes, DLT allografts comprise a very small percentage of the liver donor pool. A large proportion of potential DLTs may be unconscionably excluded despite shortages in deceased donor organs.

Liver transplantation for pediatric inherited metabolic liver diseases

Liver transplantation (LT) remains the gold standard treatment for end stage liver disease in the pediatric population. For liver based metabolic disorders (LBMDs), the decision for LT is predicated on a different set of paradigms. With improved outcomes post-transplantation, LT is no longer merely life saving, but has the potential to also significantly improve quality of life. This review summarizes the clinical presentation, medical treatment and indications for LT for some of the common LBMDs. We also provide a practical update on the dilemmas and controversies surrounding the indications for transplantation, surgical considerations and prognosis and long terms outcomes for pediatric LT in LBMDs. Important progress has been made in understanding these diseases in recent years and with that we outline some of the new therapies that have emerged.

Loss of the Drosophila branched-chain α-ketoacid dehydrogenase complex results in neuronal dysfunction

Maple syrup urine disease (MSUD) is an inherited error in the metabolism of branched-chain amino acids (BCAAs) caused by a severe deficiency of the branched-chain α-ketoacid dehydrogenase (BCKDH) complex, which ultimately leads to neurological disorders. The limited therapies, including protein-restricted diets and liver transplants, are not as effective as they could be for the treatment of MSUD due to the current lack of molecular insights into the disease pathogenesis. To address this issue, we developed a Drosophila model of MSUD by knocking out the dDBT gene, an ortholog of the human gene encoding the dihydrolipoamide branched chain transacylase (DBT) subunit of BCKDH. The homozygous dDBT mutant larvae recapitulate an array of MSUD phenotypes, including aberrant BCAA accumulation, developmental defects, poor mobile behavior and disrupted L-glutamate homeostasis. Moreover, the dDBT mutation causes neuronal apoptosis during the developmental progression of larval brains. The genetic and functional evidence generated by in vivo depletion of dDBT expression in the eye indicates severe impairment of retinal rhabdomeres. Further, the dDBT mutant shows elevated oxidative stress and higher lipid peroxidation accumulation in the larval brain. Therefore, we conclude from in vivo evidence that the loss of dDBT results in oxidative brain damage that may lead to neuronal cell death and contribute to aspects of MSUD pathology. Importantly, when the dDBT mutants were administrated with Metformin, the aberrances in BCAA levels and motor behavior were ameliorated. This intriguing outcome strongly merits the use of the dDBT mutant as a platform for developing MSUD therapies.This article has an associated First Person interview with the joint first authors of the paper.

Crigler-Najjar Syndrome Type 1: Pathophysiology, Natural History, and Therapeutic Frontier

BACKGROUND AND AIMS

We describe the pathophysiology, treatment, and outcome of Crigler-Najjar type 1 syndrome (CN1) in 28 UGT1A1 c.222C>A homozygotes followed for 520 aggregate patient-years.

APPROACH AND RESULTS

Unbound ("free") bilirubin (B_f ) was measured in patient sera to characterize the binding of unconjugated bilirubin (B_T ) to albumin (A) and validate their molar concentration ratio (B_T /A) as an index of neurological risk. Two custom phototherapy systems were constructed from affordable materials to provide high irradiance in the outpatient setting; light dose was titrated to keep B_T /A at least 30% below intravascular B_T binding capacity (i.e., B_T /A = 1.0). Categorical clinical outcomes were ascertained by chart review, and a measure (L_f ) was used to quantify liver fibrosis. Unbound bilirubin had a nonlinear relationship to B_T (R²  = 0.71) and B_T /A (R²  = 0.76), and B_f as a percentage of B_T correlated inversely to the bilirubin-albumin equilibrium association binding constant (R²  = 0.69), which varied 10-fold among individuals. In newborns with CN1, unconjugated bilirubin increased 4.3 ± 1.1 mg/dL per day. Four (14%) neonates developed kernicterus between days 14 and 45 postnatal days of life; peak B_T  ≥ 30 mg/dL and B_T /A ≥ 1.0 mol:mol were equally predictive of perinatal brain injury (sensitivity 100%, specificity 93.3%, positive predictive value 88.0%), and starting phototherapy after age 13 days increased this risk 3.5-fold. Consistent phototherapy with 33-103 µW/cm² •nm for 9.2 ± 1.1 hours/day kept B_T and B_T /A within safe limits throughout childhood, but B_T increased 0.46 mg/dL per year to reach dangerous concentrations by 18 years of age. Liver transplantation (n = 17) normalized B_T and eliminated phototherapy dependence. Liver explants showed fibrosis ranging from mild to severe.

CONCLUSION

Seven decades after its discovery, CN1 remains a morbid and potentially fatal disorder.

Domino Liver Transplantation: Where are we Now?

BACKGROUND

Domino transplant occurs when a recipient explanted graft is used for a second recipient.

INTRODUCTION

The first experience came from thoracic surgery by the observation that many patients during heart-lung transplantation actually showed a functional heart that could be employed in other subjects with a good result.

RESULTS

This concept was then extended to the field of liver transplantation. At present, some patients transplanted for an inborn metabolic disease may be considered as excellent domino liver donors.

CONCLUSION

The results, limitations, clinical challenges and the donor and recipient features of domino liver transplantation are discussed in this manuscript.

Branched-chain α-ketoacid dehydrogenase deficiency (maple syrup urine disease): Treatment, biomarkers, and outcomes

Over the past three decades, we studied 184 individuals with 174 different molecular variants of branched-chain α-ketoacid dehydrogenase activity, and here delineate essential clinical and biochemical aspects of the maple syrup urine disease (MSUD) phenotype. We collected data about treatment, survival, hospitalization, metabolic control, and liver transplantation from patients with classic (i.e., severe; n = 176), intermediate (n = 6) and intermittent (n = 2) forms of MSUD. A total of 13,589 amino acid profiles were used to analyze leucine tolerance, amino acid homeostasis, estimated cerebral amino acid uptake, quantitative responses to anabolic therapy, and metabolic control after liver transplantation. Standard instruments were used to measure neuropsychiatric outcomes. Despite advances in clinical care, classic MSUD remains a morbid and potentially fatal disorder. Stringent dietary therapy maintains metabolic variables within acceptable limits but is challenging to implement, fails to restore appropriate concentration relationships among circulating amino acids, and does not fully prevent cognitive and psychiatric disabilities. Liver transplantation eliminates the need for a prescription diet and safeguards patients from life-threatening metabolic crises, but is associated with predictable morbidities and does not reverse pre-existing neurological sequelae. There is a critical unmet need for safe and effective disease-modifying therapies for MSUD which can be implemented early in life. The biochemistry and physiology of MSUD and its response to liver transplantation afford key insights into the design of new therapies based on gene replacement or editing.

Technique and outcome of domino liver transplantation from patients with maple syrup urine disease: Expanding the donor pool for live donor liver transplantation

AIM/BACKGROUND

Domino liver transplantation (DLT) using liver allografts from patients with metabolic disorders enhances organ utilization. Short- and long-term course and outcome of these patients can impact the decision to offer this procedure to patients, especially those with diseases that can potentially be cured with liver transplant. We reviewed the outcomes of DLT from maple syrup urine disease (MSUD) patients in our large academic pediatric and adult transplant program.

METHODS

All patients receiving DLT were analyzed retrospectively with a minimum of one-year follow-up period for patient and donor characteristics, early and late postoperative complications and patient and graft survival with their MSUD donors in terms of age, weight, MELD/PELD scores, cold ischemia time, postoperative leucine levels, and peak ALT (alanine aminotransferase) levels during the first 48 postoperative hours.

RESULTS

Between 2006 and May 2019, 21 patients underwent domino liver transplantation with live donor allografts from MSUD patients. Four patients transplanted for different metabolic diseases are focus of a separate report. Seventeen patients with minimum one-year follow-up period are reported herein. The indications were primary sclerosing cholangitis (PSC, n = 4), congenital hepatic fibrosis (CHF, n = 2), alpha-1 antitrypsin deficiency (A-1 ATD, n = 2), progressive familial intrahepatic cholestasis (PFIC, n = 2), cystic fibrosis (n = 1), primary biliary cirrhosis (PBC, n = 1), neonatal hepatitis (n = 1), embryonal sarcoma (n = 1), Caroli disease (n = 1), hepatocellular carcinoma (HCC, n = 1), and chronic rejection after liver transplantations for PSC (n = 1). All patients and grafts survived at median follow-up of 6.4 years (range 1.2-12.9 years). Median domino recipient age was 16.2 years (range 0.6-64.6 years) and median MSUD recipient age was 17.6 years (range 4.8-32.1 years). There were no vascular complications during the early postoperative period, one patient had portal vein thrombosis 3 years after DLT and a meso-Rex bypass was successfully performed. Small for size syndrome (SFSS) occurred in reduced left lobe DLT recipient and was managed successfully with conservative management. Biliary stricture developed in 2 patients and was resolved by stenting. Comparison between DLT and MSUD recipients' peak postoperative ALT results and PELD/MELD scores showed lower levels in DLT group (P-value <.05).

CONCLUSIONS

Patient and graft survival in DLT from MSUD donors was excellent at short- and long-term follow-up. Metabolic functions have been normal in all recipients on a normal unrestricted protein diet. Ischemia preservation injury based on peak ALT was significantly decreased in DLT recipients. Domino transplantation from pediatric and adult recipients with selected metabolic diseases should be increasingly considered as an excellent option and alternative to deceased donor transplantation, thereby expanding the living donor pool. This, to date, is the largest world experience in DLT utilizing livers from patients with MSUD.

Domino liver transplantation for select metabolic disorders: Expanding the living donor pool

Domino liver transplantation (DLT) involves transplanting liver from a patient with metabolic disease into a patient with end-stage liver disease with the expectation that the recipient will not develop the metabolic syndrome or the recurrent syndrome will have minimal affect. The domino donor gets a deceased donor or a segment of live-donor liver through the deceased donor organ allocation system. Waitlist mortality for the domino recipient exceeds morbidity associated with getting the donor disease. Between 2015 and 2017, four patients with three metabolic disorders at UPMC Children's Hospital of Pittsburgh underwent DLT with domino allografts from maple syrup urine disease (MSUD) patients. These included patients with propionic acidemia (PA) (n = 1), Crigler-Najjar (CN) syndrome type-1 (n = 2), and carbamoyl phosphate synthetase deficiency (CPSD) (n = 1). Mean follow-up was 1.6 years (range 1.1-2.1 years). Total bilirubin levels normalized postoperatively in both CN patients and they maintain normal allograft function. The PA patient had normal to minimal elevations of isoleucine and leucine, and no other abnormalities on low protein diet supplemented with a low methionine and valine free formula. No metabolic crises have occurred. The patient with CPSD takes normal baby food. No elevation in ammonia levels have been observed in any of the patients. DLT for a select group of metabolic diseases alleviated the recipients of their metabolic defect with minimal evidence of transferrable-branched chain amino acid elevations or clinical MSUD despite increased protein intake. DLT using allografts with MSUD expands the live donor liver pool and should be considered for select metabolic diseases that may have a different enzymatic deficiency.

Surgical Aspects of Liver Transplantation and Domino Liver Transplantation in Maple Syrup Urine Disease: Analysis of 15 Donor-Recipient Pairs

Liver transplantation (LT) has been shown to be a feasible treatment in patients with severe forms of maple syrup urine disease (MSUD). Because of a sufficient extrahepatic enzyme activity in non-MSUD individuals, the organ of MSUD patients can be used as a domino graft. We performed a retrospective data collection of all LTs for MSUD carried out at the University Medical Center Hamburg-Eppendorf (2016-2018). Moreover, data from all consecutive domino LTs of the MSUD grafts either transplanted at our institution or allocated to other transplant centers were analyzed. During the study period, 15 LTs in MSUD patients were performed (12 children, 3 adults; median age, 10.9 years; range, 0.3-26.1 years). Biliary complications occurred in 20%, and 13.3% suffered from bleeding complications. No further surgical problems occurred. At present, all MSUD patients are alive with a well-functioning liver graft and on an unrestricted diet. In total, 14 consecutive domino LTs were performed. No surgical complications requiring intervention occurred. One patient died because of HCC relapse, and all other patients are alive with good liver graft function. In conclusion, the use of MSUD livers as domino grafts is safe and allows application of LT in MSUD patients without net extraction of a liver graft from the limited donor pool.

Ethical Analysis and Policy Recommendations Regarding Domino Liver Transplantation

Due to the widening gap between supply and demand, patients who need a liver transplant due to metabolic disease may be asked to serve as domino liver donors-to have their native liver transplanted into another candidate. We here analyze the ethical problems surrounding informed consent for the implant and explant procedures in transplant candidates who will serve as domino donors, using the case of a child with maple syrup urine disease. We discuss the need for 2 distinct consent processes separated in time to ensure that potential domino donors (or their surrogates) give a truly voluntary consent. We propose a Domino Donor Advocate-based on the concept of the independent living donor advocate to help the patient and/or his or her surrogates consider the risks, benefits and alternatives. Finally, we evaluate the Organ Procurement and Transplantation Network policy regarding "therapeutic organ donation" and propose several modifications to ensure that the decision by the potential domino donor (and/or his or her surrogate) is voluntary and informed.

Domino Hepatocyte Transplantation: A Therapeutic Alternative for the Treatment of Acute Liver Failure

BACKGROUND AND AIMS

Acute liver failure (ALF) is a severe syndrome with an elevated mortality rate, ranging from 40 to 80 %. Currently, liver transplantation is the only definitive treatment for these patients and new therapies aiming to treat ALF include artificial organs implant and stem cells therapy, for example. However, a major limitation of liver donors exists. Living donor liver transplantation (LDLT), split liver transplantation (SLT), and domino liver transplantation (DLT) are some of the available alternatives to treat ALF patients, but these do not reduce the number of patients on waiting lists. Herein, we discuss domino hepatocyte transplantation (DHT) using livers that would not meet transplantation criteria.

METHODS

We conducted a literature search on PubMed/Medline using acute liver failure, liver transplantation, hepatocyte transplantation, and domino liver transplantation as key words.

RESULTS

New sources of biochemically functional hepatocytes and therapeutic treatments, in parallel to organ transplantation, may improve liver injury recovery and decrease mortality rates. Moreover, the literature reports hepatocyte transplantation as a therapeutic alternative for organ shortage. However, a major challenge remains for a wide clinical application of hepatocytes therapy, i.e., the availability of sufficient amounts of cells for transplantation. Ideally, hepatocytes isolated from livers rejected for transplantation may be a promising alternative for this problem.

CONCLUSION

Our review suggests that DHT may be an excellent strategy to increase cell supplies for hepatocyte transplantation.

First case of cross-auxiliary double domino donor liver transplantation

We report a case of double domino liver transplantation in a 32-year-old woman who was diagnosed with familial amyloid polyneuropathy (FAP) and liver dysfunction. A two-stage surgical plan was designed, and one domino graft was implanted during each stage. During the first stage, an auxiliary domino liver transplantation was conducted using a domino graft from a 4-year-old female child with Wilson’s disease. After removing the right lobe of the FAP patient’s liver, the graft was rotated 90 degrees counterclockwise and placed along the right side of the inferior vena cava (IVC). The orifices of the left, middle, and right hepatic veins were reconstructed using an iliac vein patch and then anastomosed to the right side of the IVC. Thirty days later, a second domino liver graft was implanted. The second domino graft was from a 3-year-old female child with an ornithine carbamyl enzyme defect, and it replaced the residual native liver (left lobe). To balance the function and blood flow between the two grafts, a percutaneous transcatheter selective portal vein embolization was performed, and “the left portal vein” of the first graft was blocked 9 mo after the second transplantation. The liver function indices, blood ammonia, and 24-h urinary copper levels were normal at the end of a 3-year follow-up. These two domino donor grafts from donors with different metabolic disorders restored normal liver function. Our experience demonstrated a new approach for resolving metabolic disorders with domino grafts and utilizing explanted livers from children.

The first case of domino-split-liver transplantation in maple syrup urine disease

The enzymatic defect in MSUD results in accumulation of neurotoxic metabolites of BCAAs. LTX has shown to be a feasible strategy in patients non-responsive to diet. Because of sufficient enzyme activity in extrahepatic tissues in healthy people, the MSUD liver graft is a suitable domino organ. We present the first case of a technical challenging ex situ split of a MSUD domino organ transplanted into two pediatric recipients. The domino graft donor was a 21-year-old female (58 kg) suffering from MSUD with recurrent metabolic decompensation despite strict diet. The organ was allocated to a 14-year-old girl (55 kg) with primary sclerosing cholangitis. Due to excellent organ quality and suitable anatomy, a backward split for a girl of 3 months (5 kg) with decompensated liver cirrhosis due to biliary atresia was performed. The postoperative course was without relevant complications, and the three recipients were discharged on postoperative days 28, 29, and 45, respectively, with good organ function. BCAAs in plasma were normal in the two domino graft recipients, and the MSUD patient showed mildly elevated but stable BCAA concentrations despite an unrestricted diet. Split-domino LTX enabled successful transplantation of three patients of the waiting list with only one deceased donor graft.

Revisiting APOLT for Metabolic Liver Disease: A New Look at an Old Idea

Even though auxiliary partial orthotopic liver transplantation (APOLT) as a technique was popularized in the late 80s, its role in metabolic liver disease remains controversial. The slow progress in gene therapy research, high incidence of technical complications, and the problem of long term graft atrophy have been roadblocks to its wider application. Better understanding of reciprocal dynamics of portal flow and regeneration between the graft and native liver along with multiple refinements in surgical technique have improved the outcomes of this operation, making it a safe alternative to orthotopic liver transplantation for patients with a wide range of noncirrhotic metabolic liver diseases (NCMLD). The ability to perform APOLT safely has also opened up a range of exciting indications in the setting of NCMLD. This article reviews the current status of APOLT for NCMLD, technical refinements which have improved outcomes and novel indications, which have rekindled fresh interest in this procedure.

Successful living donor liver transplantation for classical maple syrup urine disease

MSUD is an autosomal recessive condition characterized by a deficiency in the enzyme, BCKDH, which catalyzes the breakdown of BCAAs. If left untreated, MSUD can result in mental retardation, central nervous system disorders, and even death. Most patients with MSUD are treated with a restricted protein diet and milk from which BCAAs have been removed. LT has been shown effective in patients with MSUD. This report describes the case of a 15-month-old boy who received a liver graft from his mother. Transplantation was successful, and the patient was then able to ingest a normal diet. Despite episodes of acute rejection, chylous ascites, and high fever (40 °C), he has shown no evidence of MSUD recurrence. These findings indicate that patients with MSUD can be successfully treated by LDLT, even when the donor is a heterozygous carrier of a mutated BCKDH gene.

Living donor domino liver transplantation using a maple syrup urine disease donor: A case series of three children - The first report from Japan

As the priority of LD-Domino LT is the safety of the first recipient, limitations and technical difficulties in the second recipient often occur. The most technically challenging part of LD-Domino LT is the reconstruction of the vessels. For the reconstruction of HVs, the native HVs were exteriorized as far as possible using a CUSA because longer extensive HVs are essential for facilitating the reconstruction. At the back table, the HVs of the domino graft were sutured together, and the single cuff of the HVs was anastomosed to the IVC by joining the orifices. The HAs, the presence of insufficient length, and multiple vessels in the whole liver rendered the reconstruction more difficult. We determined the dividing sites of the vessels according to the preoperative 3D-CT findings obtained in two institutions. This is the first case series using grafts in DLT obtained from LDLT for patients with MSUD between two institutions. In conclusion, LD-Domino LT is a safe and feasible therapeutic option to expand the donor pool by technical refinement in the reconstruction of the second recipient. Further studies with a greater accumulation of patients and a longer follow-up will be necessary to establish LD-Domino LT using an MSUD donor.

Living related versus deceased donor liver transplantation for maple syrup urine disease

Maple syrup urine disease (MSUD) is an inherited disorder of branched chain ketoacid (BCKA) oxidation associated with episodic and chronic brain disease. Transplantation of liver from an unrelated deceased donor restores 9-13% whole-body BCKA oxidation capacity and stabilizes MSUD. Recent reports document encouraging short-term outcomes for MSUD patients who received a liver segment from mutation heterozygous living related donors (LRDT). To investigate effects of living related versus deceased unrelated grafts, we studied four Brazilian MSUD patients treated with LRDT who were followed for a mean 19 ± 12 postoperative months, and compared metabolic and clinical outcomes to 37 classical MSUD patients treated with deceased donor transplant. Patient and graft survival for LRDT were 100%. Three of 4 MSUD livers were successfully domino transplanted into non-MSUD subjects. Following LRDT, all subjects resumed a protein-unrestricted diet as mean plasma leucine decreased from 224 ± 306 μM to 143 ± 44 μM and allo-isoleucine decreased 91%. We observed no episodes of hyperleucinemia during 80 aggregate postoperative patient-months. Mean plasma leucine:isoleucine:valine concentration ratios were ~2:1:4 after deceased donor transplant compared to ~1:1:1.5 following LRDT, resulting in differences of predicted cerebral amino acid uptake. Mutant heterozygous liver segments effectively maintain steady-state BCAA and BCKA homeostasis on an unrestricted diet and during most catabolic states, but might have different metabolic effects than grafts from unrelated deceased donors. Neither living related nor deceased donor transplant affords complete protection from metabolic intoxication, but both strategies represent viable alternatives to nutritional management.

Successful Domino Liver Transplantation from a Patient with Methylmalonic Acidemia

Liver transplantation has been reported in patients with methylmalonic acidemia (MMA), but long-term outcome is controversial. Many patients with other approved indications for liver transplantation die before donor grafts are available. A 28-year-old man with MMA underwent cadaveric liver transplantation. His liver was used as a domino graft for a 61-year-old man with primary sclerosing cholangitis, who had low priority on the transplant waiting list. Surgical outcome was successful, and after transplantation both patients have excellent graft function. The patient with MMA showed substantial decrease in methylmalonate in urine (from 5,277 ± 1,968 preoperatively to 1,068 ± 384 mmol/mol creatinine) and plasma (from 445.9 ± 257.0 to 333.3 ± 117.7 μmol/l) over >1-year follow-up, while dietary protein intake increased from 0.6 to 1.36 ± 0.33 g/kg/day. The domino recipient maintained near-normal levels of plasma amino acids but did develop elevated methylmalonate in blood and urine while receiving an unrestricted diet (peak plasma methylmalonate 119 μmol/l and urine methylmalonate 84-209 mmol/mol creatinine, with 1.0-1.9 g/kg/day protein). Neither patient demonstrated any apparent symptoms of MMA or metabolic decompensation during the postoperative period or following discharge.

CONCLUSION

Liver transplantation substantially corrects methylmalonate metabolism in MMA and greatly attenuates the disease. In this single patient experience, a liver from a patient with MMA functioned well as domino graft although it did result in subclinical methylmalonic acidemia and aciduria in the recipient. Patients with MMA can be considered as domino liver donors for patients who might otherwise spend long times waiting for liver transplantation.

Successful living domino liver transplantation in a child with protein C deficiency

PC is produced in the liver and inhibits blood coagulation by catalyzing active factors V and VIII. PC deficiency causes abnormal blood clotting that is difficult to regulate by anticoagulative treatments. Four reports of PC deficiency treated with LTx have been published; however, no report of DLT as a therapy for PC deficiency is available. We describe a case of a 23-month-old girl who received DLT for compound heterozygous PC deficiency. Her PC activity was below 5%. She developed intracranial lesion and frequent refractory purpura fulminans. Both her parents had heterozygous mutations of PC genes and were excluded as living donors. Furthermore, she was a low priority on the waiting list of deceased-donor transplantation. We performed living DLT using the liver from a patient with MSUD. Activated PC concentrate safely supported the perioperative period. After DLT, she maintained normal PC activities and BCAA levels. This is the first case of PC deficiency successfully treated by living DLT with MSUD. We propose that DLT using liver from patients with MSUD is a treatment option for PC deficiency.

Heterozygote to homozygote related living donor liver transplantation in maple syrup urine disease: a case report

Liver transplantation is an accepted treatment modality in the management of MSUD. To our knowledge, ours is only the second successful case to date of a patient with MSUD receiving an allograft from an RLD who is a heterozygous carrier for the disease. In view of the worldwide shortage of available organs for transplantation, heterozygote to homozygote transplantation in the setting of MSUD may provide a viable alternative for those awaiting transplantation. We report on the case of a two-yr-old infant with MSUD, who received a left lateral segment (segments II and III) liver transplant from his mother, a heterozygote carrier of one of the three abnormal genes implicated in MSUD. Post-operative BCAA levels normalized in our patient and remained so on an unrestricted protein diet and during times of physiological stress. To date, this is only the second case of a successful RLD liver transplant in a child with MSUD. Preliminary results indicate that RLD liver transplants are at least equivalent to deceased donor liver transplants in the treatment of MSUD, although longer term follow-up is required. Heterozygote to homozygote RLD transplant in patients with MSUD presents a new pool of potential liver donors.

Liver transplantation for classical maple syrup urine disease: long-term follow-up

OBJECTIVES

The aim of the study was to evaluate indications, results, and clinical and neurological evolution in children who have undergone liver transplantation for classical maple syrup urine disease (MSUD).

METHODS

Descriptive study of liver transplantation for MSUD between 1991 and 2012. Eight patients were transplanted.

RESULTS

Indications for transplant were poor metabolic control expressed as significant psychomotor disabilities (4 had psychomotor delays, 5 had spasticity, and 5 had epilepsy) and poor quality of life (mean number of acute metabolic decompensations and mean number of total hospitalizations before transplantation 5 and 12, respectively). Four required nasogastric tube, with a maximum 4 g/day protein-restricted diet in all of them. Seven sustained significant alterations in brain magnetic resonance imaging. Mean leucine and alloisoleucine levels were 608 (standard deviation [SD] 516) and 218 μmol/L (SD 216), respectively. All of the patients received transplants with deceased-donor livers, with ages between 1.5 and 2.5 years (mean 1.78 years). Mean posttransplantation follow-up period was 12.2 years (range 5-21 years). Final patient and graft survival was 87.5% and 75%, respectively. Following transplantation, none required hospitalization in the last 3 years nor did any have new acute metabolic decompensations following a normal diet. Five followed normal schooling, 2 had motor disabilities, and 2 had convulsive crises. Brain magnetic resonance imaging was taken in 4 patients, showing neuroimage improvement in 3 of them. Mean leucine levels were <350 μmol/L from the immediate posttransplantation period (mean 225 μmol/L, SD 78), with a maximum alloisoleucine level of 20 μmol/L.

CONCLUSIONS

Liver transplantation is an effective treatment for classical MSUD that arrests brain damage, although it does not reverse the process.

Nutrition management guideline for maple syrup urine disease: an evidence- and consensus-based approach

In an effort to increase harmonization of care and enable outcome studies, the Genetic Metabolic Dietitians International (GMDI) and the Southeast Regional Newborn Screening and Genetics Collaborative (SERC) are partnering to develop nutrition management guidelines for inherited metabolic disorders (IMD) using a model combining both evidence- and consensus-based methodology. The first guideline to be completed is for maple syrup urine disease (MSUD). This report describes the methodology used in its development: formulation of five research questions; review, critical appraisal and abstraction of peer-reviewed studies and unpublished practice literature; and expert input through Delphi surveys and a nominal group process. This report includes the summary statements for each research question and the nutrition management recommendations they generated. Each recommendation is followed by a standardized rating based on the strength of the evidence and consensus used. The application of technology to build the infrastructure for this project allowed transparency during development of this guideline and will be a foundation for future guidelines. Online open access of the full, published guideline allows utilization by health care providers, researchers, and collaborators who advise, advocate and care for individuals with MSUD and their families. There will be future updates as warranted by developments in research and clinical practice.

Successful domino liver transplantation in maple syrup urine disease using a related living donor

Maple syrup urine disease (MSUD) is an autosomal recessive disease associated with high levels of branched-chain amino acids. Children with MSUD can present severe neurological damage, but liver transplantation (LT) allows the patient to resume a normal diet and avoid further neurological damage. The use of living related donors has been controversial because parents are obligatory heterozygotes. We report a case of a 2-year-old child with MSUD who underwent a living donor LT. The donor was the patient's mother, and his liver was then used as a domino graft. The postoperative course was uneventful in all three subjects. DNA analysis performed after the transplantation (sequencing of the coding regions of BCKDHA, BCKDHB, and DBT genes) showed that the MSUD patient was heterozygous for a pathogenic mutation in the BCKDHB gene. This mutation was not found in his mother, who is an obligatory carrier for MSUD according to the family history and, as expected, presented both normal clinical phenotype and levels of branched-chain amino acids. In conclusion, our data suggest that the use of a related donor in LT for MSUD was effective, and the liver of the MSUD patient was successfully used in domino transplantation. Routine donor genotyping may not be feasible, because the test is not widely available, and, most importantly, the disease is associated with both the presence of allelic and locus heterogeneity. Further studies with this population of patients are required to expand the use of related donors in MSUD.

Liver transplantation for pediatric metabolic disease

Liver transplantation (LTx) was initially developed as a therapy for liver diseases known to be associated with a high risk of near-term mortality but is based upon a different set of paradigms for inborn metabolic diseases. As overall outcomes for the procedure have improved, LTx has evolved into an attractive approach for a growing number of metabolic diseases in a variety of clinical situations. No longer simply life-saving, the procedure can lead to a better quality of life even if not all symptoms of the primary disorder are eliminated. Juggling the risk-benefit ratio thus has become more complicated as the list of potential disorders amenable to treatment with LTx has increased. This review summarizes presentations from a recent conference on metabolic liver transplantation held at the Children's Hospital of Pittsburgh of UPMC on the role of liver or hepatocyte transplantation in the treatment of metabolic liver disease.

Branched-chain amino acid metabolism: from rare Mendelian diseases to more common disorders

Branched-chain amino acid (BCAA) metabolism plays a central role in the pathophysiology of both rare inborn errors of metabolism and the more common multifactorial diseases. Although deficiency of the branched-chain ketoacid dehydrogenase (BCKDC) and associated elevations in the BCAAs and their ketoacids have been recognized as the cause of maple syrup urine disease (MSUD) for decades, treatment options for this disorder have been limited to dietary interventions. In recent years, the discovery of improved leucine tolerance after liver transplantation has resulted in a new therapeutic strategy for this disorder. Likewise, targeting the regulation of the BCKDC activity may be an alternative potential treatment strategy for MSUD. The regulation of the BCKDC by the branched-chain ketoacid dehydrogenase kinase has also been implicated in a new inborn error of metabolism characterized by autism, intellectual disability and seizures. Finally, there is a growing body of literature implicating BCAA metabolism in more common disorders such as the metabolic syndrome, cancer and hepatic disease. This review surveys the knowledge acquired on the topic over the past 50 years and focuses on recent developments in the field of BCAA metabolism.

Adipose transplant for inborn errors of branched chain amino acid metabolism in mice

Liver transplantation appears to be quite beneficial for treatment of maple syrup urine disease (MSUD, an inherited disorder of branched chain amino acid metabolism); however, there is a limited availability of donor livers worldwide and the first year costs of liver transplants are quite high. Recent studies have suggested that intact adipose tissue, already widely used in reconstructive surgery, may have an underappreciated high capacity for branched chain amino acid (BCAA) metabolism. Here we examined the potential for adipose tissue transplant to lower circulating BCAAs in two models of defective BCAA metabolism, BCATm and PP2Cm [branched chain keto acid dehydrogenase complex (BCKDC) phosphatase] knockout (KO) mice. After 1-2g fat transplant, BCATm and PP2Cm KO mice gained or maintained body weight 3weeks after surgery and consumed similar or more food/BCAAs the week before phlebotomy. Transplant of fat into the abdominal cavity led to a sterile inflammatory response and nonviable transplanted tissue. However when 1-2g of fat was transplanted subcutaneously into the back, either as small (0.1-0.3g) or finely minced pieces introduced with an 18-ga. needle, plasma BCAAs decreased compared to Sham operated mice. In two studies on BCATm KO mice and one study on PP2Cm KO mice, fat transplant led to 52-81% reductions in plasma BCAAs compared to baseline plasma BCAA concentrations of untreated WT type siblings. In PP2Cm KO mice, individual BCAAs in plasma were also significantly reduced by fat transplant, as were the alloisoleucine/Phe ratios. Therefore, subcutaneous fat transplantation may have merit as an adjunct to dietary treatment of MSUD. Additional studies are needed to further refine this approach.

Domino liver transplantation in maple syrup urine disease: a case report and review of the literature

BACKGROUND

Improved outcomes have expanded the indications for liver transplantation, thus aggravating the already limited supply of donor organs. Domino liver transplantation (DLT) has been one strategy to augment the supply of donor organs in cases of inborn errors of metabolism. One such disease is maple syrup urine disease (MSUD), an inherited disorder of branched-chain amino acid (BCAA) metabolism.

METHODS

We report on the transplantation of a deceased donor liver into a patient with MSUD, and the sequential transplantation of the explanted liver into a patient with hemophilia A, HIV, hepatitis C, and a low priority on the transplant waiting list.

RESULTS

At 30 months, the MSUD recipient has had significant correction of BCAA metabolism on a protein-unrestricted diet and no progression of neuropsychiatric symptoms. The DLT recipient has been cured of hemophilia and has normal BCAA homeostasis. This case provides further evidence that elective orthotopic liver transplantation for MSUD attenuates the disease with restoration of BCAA metabolism, and that DLT in this setting can achieve excellent results in ESLD patients.

CONCLUSION

It is possible that domino grafts from patients with MSUD could be used in more conventional recipients, but additional studies and longer-term outcomes are needed to determine the validity of DLT in MSUD.

Stevens-Johnson syndrome after Mycoplasma pneumonia infection in pediatric post-liver transplant recipient: case report and review of the literature

Although Mycoplasma pneumonia infection is relatively common among school-aged children, it rarely leads to SJS. Herein, we report a seven-yr-old girl who presented with a Mycoplasma pneumonia infection that progressed to SJS five months after liver transplant. We suggest that children presenting with symptoms of Mycoplasma pneumonia infection in the immunosuppressed post-liver transplant setting be properly diagnosed and treated rapidly, as well as observed for symptoms of SJS and potentially serious extrapulmonary complications.

Liver transplantation for classical maple syrup urine disease: long-term follow-up in 37 patients and comparative United Network for Organ Sharing experience

OBJECTIVE

To assess clinical and neurocognitive function in children who have undergone liver transplantation for classical maple syrup urine disease (MSUD).

STUDY DESIGN

A total of 35 patients with classical MSUD (age 9.9 ± 7.9 years) underwent liver transplantation between 2004 and 2009. Six patients donated their liver to recipients without MSUD ("domino" transplant). We analyzed clinical outcomes for our cohort and 17 additional cases from the national United Network for Organ Sharing registry; 33 patients completed IQ and adaptive testing before transplantation, and 14 completed testing 1 year later.

RESULTS

Patient and graft survival were 100% at 4.5 ± 2.2 years of follow-up. Liver function was normal in all patients. Branched-chain amino acid levels were corrected within hours after surgery and remained stable, with leucine tolerance increasing more than 10-fold. All domino transplant recipients were alive and well with normal branched-chain amino acid homeostasis at the time of this report. Patient and graft survival for all 54 patients with MSUD undergoing liver transplantation in the United States during this period were 98% and 96%, respectively. One-third of our patients were mentally impaired (IQ ≤ 70) before transplantation, with no statistically significant change 1 year later.

CONCLUSION

Liver transplantation is an effective long-term treatment for classical MSUD and may arrest brain damage, but will not reverse it.

Domino liver transplantation: how far can we push the paradigm?

Domino liver transplantation (DLT) has emerged as a strategy for increasing the number of liver grafts available: morphologically normal livers from donors with metabolic diseases can be used for select recipients with hepatocellular carcinoma (usually outside the Milan criteria). Familial amyloidotic polyneuropathy (FAP) is the most common indication for DLT. When FAP patients are involved in DLT, the indications and outcomes are clear and good, although de novo FAP development within various periods of time has been described in DLT recipients of FAP livers. With the increasing need for organs, livers explanted from patients with rare metabolic diseases, such as primary hyperoxaluria (PH), acute intermittent porphyria (AIP), maple syrup urine disease (MSUD), and homozygous familial hypercholesterolemia (HFHC), are being used for DLT. However, insufficient data about the use of livers from patients with these rare metabolic diseases are available. In this review, we focus on the latter disorders. PH is not a good indication for DLT because recipients of PH livers develop hyperoxaluria and early acute renal failure. AIP also seems to be a debatable indication for DLT because of the rapid development of neurotoxicity in AIP liver recipients. However, the outcomes of DLT with HFHC and MSUD liver grafts (which include the risk of the de novo development of these genetic diseases) are promising. For rare metabolic liver diseases to be established as indications for DLT, more reports and studies are needed.

Domino liver transplantation: indications, techniques, and outcomes

The long-term shortage of livers available for transplantation has spurred the development of many strategies to bolster the donor organ supply. One particularly innovative strategy is domino liver transplantation in which a select group of liver transplant recipients can donate their explanted native livers for use as liver grafts in other patients. Several hereditary metabolic diseases (such as familial amyloid polyneuropathy, maple syrup urine disease, and familial hypercholesterolemia) are caused by aberrant or deficient protein production in the liver, and these conditions can be cured with an orthotopic liver transplant. Although their native livers eventually caused severe systemic disease in these patients, these livers are otherwise structurally and functionally normal, and they have been used successfully in domino liver transplants for the past 15 years. This article will review the indications for donating or receiving a domino liver transplant, the surgical techniques necessary to perform these transplants, as well as the recently revealed long-term outcomes and risks of domino transplantation.

Domino liver graft from a patient with homozygous familial hypercholesterolemia

HFH is a metabolic disease caused by a defect in the gene that encodes the synthesis of the cellular receptor for LDL-Rs. A high plasma level of cholesterol is present from birth and leads to severe atherosclerosis in childhood, and death from myocardial infarction usually occurs before the age of 20 yr. The liver contains approximately 50-75% of the total body LDL-Rs; therefore, liver transplantation has been carried out to treat this metabolic disorder effectively. The rationale for using an HFH liver for a domino graft is that the absence of functional LDL-Rs in the liver may be compensated for by the extra-hepatic LDL-Rs. Therefore, an HFH liver can possibly be used as a domino graft for a recipient with a normal plasma cholesterol level before transplantation. We herein report a domino liver transplantation using an HFH liver as a domino graft with successful results. To expand the donor pool, especially in Asian countries, domino grafts from HFH should be encouraged by careful selection of the domino recipient.

Hepatocyte transplantation (HTx) corrects selected neurometabolic abnormalities in murine intermediate maple syrup urine disease (iMSUD)

Skvorak et al. [1] demonstrated the therapeutic efficacy of HTx in a murine model of iMSUD, confirming significant metabolic improvement and survival. To determine the effect of HTx on extrahepatic organs, we examined the metabolic effects of HTx in brain from iMSUD animals. Amino acid analysis revealed that HTx corrected increased ornithine, partially corrected depleted glutamine, and revealed a trend toward alloisoleucine correction. For amino acid and monoamine neurotransmitters, decreased GABA was partially corrected with HTx, while the l-histidine dipeptide of GABA, homocarnosine, was decreased in iMSUD mice and hypercorrected following HTx. Elevated branched-chain amino acids (BCAA; leucine, isoleucine, and valine) in MSUD can deplete brain tyrosine and tryptophan (the precursors of monoamine neurotransmitters, dopamine (DA) and serotonin (5-hydroxytryptamine; 5-HT)) through competition via the large neutral amino acid transporter. HTx corrected decreased DA levels and the DA metabolite, 3-methoxytyramine, and partially corrected the DA intermediate 3,4-dihydroxyphenylacetate (DOPAC) and 5-HT levels, despite normal tyrosine and tryptophan levels in iMSUD mouse brain. We further observed enhanced intracellular turnover of both DA and 5-HT in iMSUD mouse brain, both of which partially corrected with HTx. Our results suggest new pathomechanisms of neurotransmitter metabolism in this disorder and support the therapeutic relevance of HTx in iMSUD mice, while providing proof-of-principle that HTx has corrective potential in extrahepatic organs.

Domino liver transplantation using a graft from a donor with familial hypercholesterolemia: seven-yr follow-up

A 46-yr-old female with hepatocellular carcinoma and severe hepatitis B-related liver cirrhosis received a domino liver graft from a 25-yr-old female with homozygous familial hypercholesterolemia (HFHC) in September 2001. Hypercholesterolemia occurred in the graft recipient within one yr after transplantation and was partially controlled by atorvastatin. Three yr after transplantation, an autologous CD34(+) cell transplantation was performed in order to better control the hypercholesterolemia. Only preliminary results of this domino liver transplantation (DLT) were published in 2003, without a long-term analysis of the hypercholesterolemic effects in recipient. Subsequent to DLT, the average plasma cholesterol level in the domino donor rapidly normalized and seven yr after had a value of 182 mg/dL. After seven-yr follow-up, the domino recipient has no hepatocarcinoma recurrence. Moreover, no signs of cardiovascular or atherosclerotic lesions were noted despite an elevated plasma cholesterol level (339 mg/dL after seven yr of follow-up) resistant to drug therapy and stem cell autotransplantation. In conclusion, DLT using a liver graft from a patient with HFHC provides a viable option for marginal recipients.

Metabolic liver disease in children

The aim of this article is to provide essential information for hepatologists, who primarily care for adults, regarding liver-based inborn errors of metabolism with particular reference to those that may be treatable with liver transplantation and to provide adequate references for more in-depth study should one of these disease states be encountered.

Metabolic liver disease in children

The aim of this article is to provide essential information for hepatologists, who primarily care for adults, regarding liver-based inborn errors of metabolism with particular reference to those that may be treatable with liver transplantation and to provide adequate references for more in-depth study should one of these disease states be encountered.