Transmission of systemic transthyretin amyloidosis by means of domino liver transplantation

Multi-organ structural homogeneity of amyloid fibrils in ATTRv-T60A amyloidosis patients, revealed by Cryo-EM

ATTR amyloidosis is a degenerative disorder characterized by the systemic deposition of the protein transthyretin. These amyloid aggregates of transthyretin (ATTR) can deposit in different parts of the body causing diverse clinical manifestations. Our laboratory aims to investigate a potential relationship between the different genotypes, organ of deposition, clinical phenotypes, and the structure of ATTR fibrils. Using cryo-electron microscopy, we have recently described how the neuropathic related mutations ATTRv-I84S and ATTRv-V122Δ can drive structural polymorphism in ex vivo fibrils. Here we question whether the mutation ATTRv-T60A, that commonly triggers cardiac and neuropathic symptoms, has a similar effect. To address this question, we extracted and determined the structure of ATTR-T60A fibrils from multiple organs (heart, thyroid, kidney, and liver) from the same patient and from the heart of two additional patients. We have found a consistent conformation among all the fibril structures, acquiring the "closed-gate morphology" previously found in ATTRwt and others ATTRv related to cardiac or mixed manifestations. The closed-gate morphology is composed by two segments of the protein that interact together forming a polar channel, where the residues glycine 57 to isoleucine 68 act as a gate of the polar cavity. Our study indicates that ATTR-T60A fibrils present in peripheral organs adopt the same structural conformation in all patients, regardless of the organ of deposition.

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.

Ocular findings in patients with acquired ATTRv amyloidosis following domino liver transplantation

PURPOSE

To investigate the presence of amyloidosis-related ocular findings in patients who received domino liver transplantation from ATTRv amyloidosis donors.

METHODS

We reviewed the ocular findings in patients who had previously undergone domino liver transplantation and received ophthalmologic examinations between January 2009 and March 2023. The presence of amyloidosis-related ocular findings was retrospectively assessed by two ophthalmologists.

RESULTS

During the study period, a total of 7 patients with 14 eyes were examined. All patients were considered as acquired ATTRv amyloidosis. The mean age at the final visit was 64.6±8.4 years (52-75 years), and the mean time since domino liver transplantation was 167.6±76.2 months (69-257 months). The two evaluators' assessments for amyloidosis-related ocular findings were completely identical. No amyloid fibril deposition was observed in the pupil, lens, or vitreous. Five patients (10 eyes) had a Schirmer test result of 5mm or less than 5 mm, and four patients with a total of 8 eyes underwent fluorescein angiography and indocyanine green angiography, and no evidence of retinal amyloid angiopathy was found on fluorescein angiography. However, three patients with 6 eyes showed choroidal amyloid angiopathy on indocyanine green angiography.

CONCLUSION

While cases of choroidal amyloid angiopathy were observed, serious amyloidosis-related ocular complications such as vitreous opacity or secondary glaucoma did not occur even in the long term after domino liver transplantation.

Treatment of acquired transthyretin amyloidosis in domino liver transplantation

BACKGROUND

Domino liver transplantation (DLT) has been commonly used during the last two decades to partly meet the high need for liver transplants. However, the recipients of grafts from patients with noncirrhotic inherited metabolic disorders may ultimately develop metabolic syndrome, and management is usually intricate, being complicated by the underlying initial disorder, other comorbidities, and post-transplantation conditions.

CASE

We report here the management and the outcome in a patient with acquired transthyretin amyloidosis after DLT and significant comorbidities. Final treatment with a transthyretin gene silencing agent, patisiran, was well tolerated and resulted in remission of the aggravating neurological deficits in a follow-up period of 2 years.

CONCLUSIONS

The case presented here supports the concept that patisiran can target the hepatocytes producing the mutated transthyretin in acquired transthyretin amyloidosis, as efficiently as in hereditary transthyretin amyloidosis (hATTR), and can be used to treat patients with transthyretin amyloidosis after DLT.

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.

[de novo hATTR amyloidosis after domino transplantation of a donor's liver: a case report for the use of Patisiran]

Hereditary transthyretin-mediated (hATTR) amyloidosis is a rare, rapidly progressing, and potentially life-threatening disease caused by one of more than 120 mutations in the transthyretin (TTR) gene. As a result of the cumulative amyloid deposits, especially in the peripheral nerves and the heart, the majority of patients develop progressive, peripheral sensorimotor polyneuropathy and biventricular cardiomyopathy over time.Since TTR - and its amyloidogenic variants too - is predominantly synthesized in the liver, early, orthotopic liver transplantation (LTx) is a treatment option that can be used to potentially stop the progression of hATTR amyloidosis.The actual case shows a patient with hepatocellular carcinoma who received the organ of a patient with hATTR as part of a domino liver transplantation. After approximately 10 years, the patient started to develop the characteristic symptoms of the metabolic disorder. Because of a further progression of the amyloidosis, therapy with the RNA interference therapeutic patisiran was initiated, which temporarily halted the progression.

Treatment With Diflunisal in Domino Liver Transplant Recipients With Acquired Amyloid Neuropathy

Objectives: To analyze the efficacy and tolerability of diflunisal for the treatment of acquired amyloid neuropathy in domino liver transplant recipients. Methods: We performed a retrospective longitudinal study of prospectively collected data for all domino liver transplant recipients with acquired amyloid neuropathy who received diflunisal at our hospital. Neurological deterioration was defined as an score increase of ≥2 points from baseline on the Neurological Impairment Scale/Neurological Impairment Scale-Lower Limbs. Results: Twelve patients who had received compassionate use treatment with diflunisal were identified, of whom seven had follow-up data for ≥12 months. Five patients (71.4%) presented with neurological deterioration on the Neurological Impairment Scale after 12 months (p = 0.0382). The main adverse effects were cardiovascular and renal, leading to diflunisal being stopped in five patients and the dose being reduced in two patients. Conclusion: Our study suggests that most domino liver transplant recipients with acquired amyloid neuropathy will develop neurological deterioration by 12 months of treatment with diflunisal. This therapy was also associated with a high incidence of adverse effects and low treatment retention. The low efficacy and low tolerability of diflunisal treatment encourage the search for new therapeutic options.

High-avidity binding drives nucleation of amyloidogenic transthyretin monomer

Amyloidosis involves stepwise growth of fibrils assembled from soluble precursors. Transthyretin (TTR) naturally folds into a stable tetramer, whereas conditions and mutations that foster aberrant monomer formations facilitate TTR oligomeric aggregation and subsequent fibril extension. We investigated the early assembly of oligomers by WT TTR compared with its V30M and V122I variants. We monitored time-dependent redistribution among monomer, dimer, tetramer, and oligomer contents in the presence and absence of multimeric TTR seeds. The seeds were artificially constructed recombinant multimers that contained 20–40 TTR subunits via engineered biotin-streptavidin (SA) interactions. As expected, these multimer seeds rapidly nucleated TTR monomers into larger complexes, while having less effect on dimers and tetramers. In vivo, SA-induced multimers formed TTR-like deposits in the heart and the kidney following i.v. injection in mice. While all 3 variants prominently deposited glomerulus in the kidney, only V30M resulted in extensive deposition in the heart. The cardiac TTR deposits varied in size and shape and were localized in the intermyofibrillar space along the capillaries. These results are consistent with the notion of monomeric TTR engaging in high-avidity interactions with tissue amyloids. Our multimeric induction approach provides a model for studying the initiation of TTR deposition in the heart.

Domino transplantation for pediatric liver recipients: Obstacles, challenges, and successes

BACKGROUND

Domino liver transplantation aims to address the need to increase the liver donor supply. In a domino liver transplant, the domino recipient receives the explanted liver from the recipient of a traditional liver transplant. The domino donor typically requires liver transplant to correct a metabolic disorder; the explanted liver thus has a single gene defect but otherwise normal structure and function.

METHODS

In this review, we detail the history of domino liver transplantation, appropriate domino donor indications, the technical advances to the surgical approach, current outcomes, and future opportunities.

RESULTS

Development of de novo disease in the domino recipient has relegated adult domino liver transplant to be considered a source of marginal donor livers. However, pediatric domino liver transplant has leveraged certain metabolic disorders, especially maple syrup urine disease, in which the liver enzyme deficiency can be compensated by the systemic presence of sufficient enzyme. Advances in the surgical aspects of assuring adequate length of vasculature have improved the safety of the procedure in both domino donors and recipients.

CONCLUSIONS

Pediatric domino liver transplant utilizing domino donors with specific metabolic liver diseases should be considered a viable live donor option for children awaiting liver transplant.

Targeted treatments of AL and ATTR amyloidosis

The therapeutic landscape for cardiac amyloidosis is rapidly evolving. In the last decade, our focus has shifted from dealing with the inevitable complications of continued extracellular infiltration of amyloid fibrils to earlier identification of these patients with prompt initiation of targeted therapy to prevent further deposition. Although much of the focus on novel targeted therapies is within the realm of transthyretin amyloidosis, light chain amyloidosis has benefited due to an overlap particularly in the final common pathway of fibrillogenesis and extraction of amyloid fibrils from the heart. Here, we review the targeted therapeutics for transthyretin and light chain amyloidosis. For transthyretin amyloidosis, the list of current and future therapeutics continues to evolve; and therefore, it is crucial to become familiar with the underlying mechanistic pathways of the disease. Although targeted therapeutic choices in AL amyloidosis are largely driven by the hematology team, the cardiac adverse effect profiles of these therapies, particularly in those with advanced amyloidosis, provide an opportunity for early recognition to prevent decompensation and can help inform recommendations regarding therapy changes when required.

Effects of a Domino Liver Transplantation Program on Patient Survival and Waiting List Time: A Single-Center Retrospective Study

Explanted livers from patients with familial amyloid polyneuropathy have often been used for domino liver transplantation (DLT). This has expanded the organ pool for liver transplantation. We evaluated the effects of a single-center DLT program on waiting list duration and patient survival. Liver transplants conducted from 2007 to 2017 were analyzed. Selected patients, all liver transplant candidates above the age of 60 years and patients with hepatocellular carcinoma, were offered DLT. Survival, time on waiting list, and operative factors were evaluated. The study group included 485 patients transplanted with grafts from deceased donors (conventional liver transplantation) and 149 patients who were offered and accepted a potential DLT, of whom 34 underwent DLT and 115 did not; these patients received a deceased donor graft (non-DLT). Five-year and overall estimated survival rates respectively were 79% and 54.4% for DLT and 67.6% and 46.7% for non-DLT (P = .67, log rank test). No differences were noted in survival (P = .816) or waiting times (P = 1.0) between DLT and non-DLT groups. As expected, survival time in the conventional liver transplantation group was longer (84.7% and 60.6%, P < .001). Donor age and ischemia time were significantly different between DLT and non-DLT (P < .001). DLT has enabled 6% additional transplantations without affecting waiting time or survival (34/600).

Are we creating a new phenotype? Physiological barriers and ethical considerations in the treatment of hereditary transthyretin-amyloidosis

Hereditary transthyretin (TTR) amyloidosis (ATTRv) is an autosomal dominant, systemic disease transmitted by amyloidogenic mutations in the TTR gene. To prevent the otherwise fatal disease course, TTR stabilizers and mRNA silencing antisense drugs are currently approved treatment options. With 90% of the amyloidogenic protein produced by the liver, disease progression including polyneuropathy and cardiomyopathy, the two most prominent manifestations, can successfully be halted by hepatic drug targeting or-formerly-liver transplantation. Certain TTR variants, however, favor disease manifestations in the central nervous system (CNS) or eyes, which is mostly associated with TTR production in the choroid plexus and retina. These compartments cannot be sufficiently reached by any of the approved medications. From liver-transplanted patients, we have learned that with longer lifespans, such CNS manifestations become more relevant over time, even if the underlying TTR mutation is not primarily associated with such. Are we therefore creating a new phenotype? Prolonging life will most likely lead to a shift in the phenotypic spectrum, enabling manifestations like blindness, dementia, and cerebral hemorrhage to come out of the disease background. To overcome the first therapeutic limitation, the blood-brain barrier, we might be able to learn from other antisense drugs currently being used in research or even being approved for primary neurodegenerative CNS diseases like spinal muscular atrophy or Alzheimer's disease. But what effects will unselective CNS TTR knock-down have considering its role in neuroprotection? A potential approach to overcome this second limitiation might be allele-specific targeting, which is, however, still far from clinical trials. Ethical standpoints underline the need for seamless data collection to enable more evidence-based decisions and for thoughtful consenting in research and clinical practice. We conclude that the current advances in treating ATTRv amyloidosis have become a meaningful example for mechanism-based treatment. With its great success in improving patient life spans, we will still have to face new challenges including shifts in the phenotype spectrum and the ongoing need for improved treatment precision. Further investigation is needed to address these closed barriers and open questions.

High and Low Frequency Domino Liver Transplantation Centers Demonstrate Similar Performance Outcomes

INTRODUCTION

A Domino Liver Transplant (DLT) is a successfully validated surgical option for a subset of patients awaiting liver transplant. Increased utilization of DLTs could increase the donor organ pool. However, DLTs occur primarily at a small number of high volume centers, and are rarely performed at lower volume transplant centers. This study compares DLT recipient performance outcomes between high frequency DLT centers and low frequency DLT centers.

METHODS

The UNOS/OPTN STAR database was queried for DLTs performed at transplant centers between 1996-2018. 193 patients were identified and categorized into high (>5 DLTs) or low (≤5 DLTs) frequency centers. Our primary endpoint was allograft survival. Our secondary endpoints were graft status at last follow up and mortality secondary to cardiac, renal, or respiratory failure.

RESULTS

Overall median allograft survival between high and low volume DLT centers was similar (48.2 months versus 42.7 months, P >0.314). The one-year (82% versus 76%), three-year (57% versus 56%), and five-year (45% versus 43%) survival percentages were also similar between the high and low volume DLT centers respectively. Overall mortality from cardiac (high 4% versus low 1.7%), renal (high 0.8% versus low 1.7%), or respiratory failure (high 0.8% versus low 1.7%) was similarly low in both groups.

CONCLUSION

Low volume and high volume DLT centers are associated with similar outcomes of allograft survival and mortality. DLTs should be utilized more frequently, when the criteria are met, including in centers with limited experience, to expand the donor pool, decrease time on the waitlist, and improve overall survival.

DISCLOSURES

There are no disclosures. The authors report no proprietary or commercial interest in any product mentioned or concept discussed in this article.

Expanding Indications for Liver Transplant: Tumor and Patient Factors

During the past few decades, liver transplant has developed from a high-mortality procedure to an almost routine procedure with good survival outcomes. The development of living donor liver transplant has increased the availability of liver grafts, and the scope of indications for liver transplant has been expanding ever since. The aim of this review is to provide an overview of such an expansion of scope. Various criteria have been proposed to expand the eligibility of patients with hepatocellular carcinoma exceeding the Milan criteria for liver transplant. Furthermore, liver transplant is increasingly performed as a treatment modality for cholangiocarcinoma, neuroendocrine liver metastasis and colorectal liver metastasis. The number of elderly patients receiving liver transplant is on the rise. Combined organ transplantation has also been adopted to treat patients with multiple organ failure. Going forward, further development of preoperative noninvasive predictors in tumor, patient and even donor factors is needed to identify patients at risk of poor outcomes and hence optimize patient management.

Modulation of the Mechanisms Driving Transthyretin Amyloidosis

Transthyretin (TTR) amyloidoses are systemic diseases associated with TTR aggregation and extracellular deposition in tissues as amyloid. The most frequent and severe forms of the disease are hereditary and associated with amino acid substitutions in the protein due to single point mutations in the TTR gene (ATTRv amyloidosis). However, the wild type TTR (TTR wt) has an intrinsic amyloidogenic potential that, in particular altered physiologic conditions and aging, leads to TTR aggregation in people over 80 years old being responsible for the non-hereditary ATTRwt amyloidosis. In normal physiologic conditions TTR wt occurs as a tetramer of identical subunits forming a central hydrophobic channel where small molecules can bind as is the case of the natural ligand thyroxine (T₄). However, the TTR amyloidogenic variants present decreased stability, and in particular conditions, dissociate into partially misfolded monomers that aggregate and polymerize as amyloid fibrils. Therefore, therapeutic strategies for these amyloidoses may target different steps in the disease process such as decrease of variant TTR (TTRv) in plasma, stabilization of TTR, inhibition of TTR aggregation and polymerization or disruption of the preformed fibrils. While strategies aiming decrease of the mutated TTR involve mainly genetic approaches, either by liver transplant or the more recent technologies using specific oligonucleotides or silencing RNA, the other steps of the amyloidogenic cascade might be impaired by pharmacologic compounds, namely, TTR stabilizers, inhibitors of aggregation and amyloid disruptors. Modulation of different steps involved in the mechanism of ATTR amyloidosis and compounds proposed as pharmacologic agents to treat TTR amyloidosis will be reviewed and discussed.

Starting at the beginning: endoplasmic reticulum proteostasis and systemic amyloid disease

Systemic amyloid diseases are characterized by the deposition of an amyloidogenic protein as toxic oligomers and amyloid fibrils on tissues distal from the site of protein synthesis. Traditionally, these diseases have been viewed as disorders of peripheral target tissues where aggregates are deposited, and toxicity is observed. However, recent evidence highlights an important role for endoplasmic reticulum (ER) proteostasis pathways within tissues synthesizing and secreting amyloidogenic proteins, such as the liver, in the pathogenesis of these disorders. Here, we describe the pathologic implications of ER proteostasis and its regulation on the toxic extracellular aggregation of amyloidogenic proteins implicated in systemic amyloid disease pathogenesis. Furthermore, we discuss the therapeutic potential for targeting ER proteostasis to reduce the secretion and toxic aggregation of amyloidogenic proteins to mitigate peripheral amyloid-associated toxicity involved in the onset and progression of systemic amyloid diseases.

Domino living donor liver transplantation of familial amyloid polyneuropathy patient - A case report

Background

Familial amyloid polyneuropathy (FAP) is caused by mutation in a gene transcribing transport protein produced mainly by the liver. Liver transplantation is required to stop FAP progression, but the pathology causes anesthetic management challenges.

Case

We report a case of domino living donor liver transplantation in an FAP patient. No intraoperative events occurred; however, during postoperative day 1 in the intensive care unit (ICU), the FAP patient underwent multiple cardiopulmonary resuscitation (CPR) sessions due to pulseless electrical activity following a sudden drop in blood pressure and ventricular tachycardia. Despite ICU management, the patient died after the third CPR session.

Conclusions

Various anesthetic management techniques should be considered for FAP patients. Anesthetic management was carefully assessed with the use of isoflurane, isoproterenol, and an external patch. The cause of deterioration in the ICU is unclear, but further investigation is needed to prevent and better manage postoperative morbidity and mortality.

Domino-liver transplantation: toward a safer and simpler technique in both donor and recipient

Domino-liver transplantation represents a rare chance to expand the donor liver pool. Fear of putting both donor and recipient at disadvantage has meant that the procedure has not been applied universally. A modification of the original technique which allows both safe procurement of the graft as well as safe implantation of the reconstructed graft in the domino-graft recipient using a 180° rotated, adequately trimmed, free iliaco-caval venous graft is described in detail.

Transthyretin Amyloidosis: Update on the Clinical Spectrum, Pathogenesis, and Disease-Modifying Therapies

ATTR amyloidosis is caused by systemic deposition of transthyretin (TTR) and comprises ATTRwt (wt for wild-type) amyloidosis, ATTRv (v for variant) amyloidosis, and acquired ATTR amyloidosis after domino liver transplantation. ATTRwt amyloidosis has classically been regarded as cardiomyopathy found in the elderly, whereas carpal tunnel syndrome has also become a major initial manifestation. The phenotypes of ATTRv amyloidosis are diverse and include neuropathy, cardiomyopathy, and oculoleptomeningeal involvement as the predominant features, depending on the mutation and age of onset. In addition to variant TTR, the deposition of wild-type TTR plays a significant role, even in patients with ATTRv amyloidosis. The formation of amyloid fibrils tends to occur in association with the basement membrane. The thickening or reduplication of the basement membrane surrounding endoneurial microvessels, which is similar to diabetic neuropathy, is observed in ATTRv amyloidosis, suggesting that common mechanisms, such as an accumulation of advanced glycation end products, may participate in the disease process. In addition to direct damage caused by amyloid fibrils, recent studies have suggested that the toxicity of nonfibrillar TTRs, such as TTR oligomers, participates in the process of tissue damage. Although liver transplantation has been performed for patients with ATTRv amyloidosis since 1990, late-onset patients were not eligible for this treatment. However, as the efficacy of orally administered tafamidis and diflunisal, which stabilize TTR tetramers, was suggested in the early 2010s, such late-onset patients have also become targets for disease-modifying therapies. Additionally, recent studies of small interfering RNA (patisiran) and antisense oligonucleotide (inotersen) therapies have demonstrated the efficacy of these gene-silencing agents. A strategy for monitoring patients that enables the choice of an appropriate treatment from comprehensive and long-term viewpoints should be established. As many patients with ATTR amyloidosis are aged and have heart failure, they are at increased risk of aggravation if they are infected by SARS-CoV2. The optimal interval of evaluation should also be considered, particularly in this COVID-19 era.

Expression of Amyloidogenic Transthyretin Drives Hepatic Proteostasis Remodeling in an Induced Pluripotent Stem Cell Model of Systemic Amyloid Disease

The systemic amyloidoses are diverse disorders in which misfolded proteins are secreted by effector organs and deposited as proteotoxic aggregates at downstream tissues. Although well described clinically, the contribution of synthesizing organs to amyloid disease pathogenesis is unknown. Here, we utilize hereditary transthyretin amyloidosis (ATTR amyloidosis) induced pluripotent stem cells (iPSCs) to define the contribution of hepatocyte-like cells (HLCs) to the proteotoxicity of secreted transthyretin (TTR). To this end, we generated isogenic, patient-specific iPSCs expressing either amyloidogenic or wild-type TTR. We combined this tool with single-cell RNA sequencing to identify hepatic proteostasis factors correlating with destabilized TTR production in iPSC-derived HLCs. By generating an ATF6 inducible patient-specific iPSC line, we demonstrated that enhancing hepatic ER proteostasis preferentially reduces the secretion of amyloidogenic TTR. These data highlight the liver's capacity to chaperone misfolded TTR prior to deposition, and moreover suggest the potential for unfolded protein response modulating therapeutics in the treatment of diverse systemic amyloidoses.

Living donor domino liver transplantation in a hepatitis C virus/human immunodeficiency virus-coinfected hemophilia patient: a case report

Background

Outcome of the liver transplantation (LT) is worse in hepatitis C virus (HCV)/human immunodeficiency virus (HIV)-coinfected patients compared to patients infected with HCV alone. We report the world’s first case of living donor domino liver transplantation (LDDLT) using a familial amyloid polyneuropathy (FAP) liver in a coinfected recipient with HCV-related liver cirrhosis.

Case presentation

The recipient was a 43-year-old male with a CD4 cell count of 52/μL and undetectable HIV-RNA at the time of LT. He received a domino liver graft from a 41-year-old female with FAP. No acute cellular rejection or infection occurred after LT. HCV recurrence was confirmed histologically on the posttransplant day 34. Peginterferon/ribavirin therapy resulted in non-response; however, the patient achieved a sustained viral response with sofosbuvir (SOF)/ledipasvir (LDV). Currently, HCV and HIV testing are negative, and symptomatic de novo amyloidosis has not occurred.

Conclusions

LDDLT allows successful LT in HCV/HIV-coinfected patients; posttransplant HCV recurrence can be successfully treated with anti-viral therapy.

Solid Organ Transplantation in Amyloidosis

Amyloidosis comprises a diverse group of diseases characterized by misfolding of precursor proteins which eventually form amyloid aggregates and preceding intermediaries, which are deposited in target tissues causing progressive organ damage. In all forms of amyloidosis, vital organs may fail; depending on the specific amyloidosis type, this may occur rapidly or progress slowly. Beyond therapies to reduce the precursor protein (chemotherapy for light chain [AL] amyloidosis, anti-inflammatory therapy in serum A amyloid-osis [AA], and antisense RNA therapy in transthyretin amyloidosis [ATTR]), organ transplantation may also be a means to reduce amyloidogenic protein, e.g., in types of amyloid-osis in which the variant precursor is produced by the liver. Heart transplantation is a life-saving approach to the treatment of patients with advanced cardiac amyloidosis; however, amyloidosis may still be considered a contraindication to the procedure despite data supporting improved outcomes, similar to patients with other indications. Kidney transplantation is associated with particularly favorable outcomes in patients with amyloidosis, especially if the precursor protein has been eliminated. Overall, outcomes of solid organ transplantation are improving, but more data are needed to refine the selection criteria and the timing for organ transplantation, which should be performed in highly experienced centers involving multidisciplinary teams with close patient follow-up to detect amyloid recurrence.

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.

Characteristics of acquired transthyretin amyloidosis: A case series and review of the literature

OBJECTIVE

To elucidate the clinical characteristics of acquired ATTR amyloidosis after domino liver transplantation (DLT) with liver grafts explanted from patients with hereditary variant ATTR (ATTRv) amyloidosis.

METHODS

We evaluated the presence of amyloid deposits and clinical symptoms in 30 recipients of domino liver transplants (24 men and 6 women) who underwent DLT with liver grafts explanted from patients with ATTRv amyloidosis. We analyzed symptoms and measures of 7 cases of symptomatic acquired ATTR amyloidosis and compared those with 30 patients with ATTRv amyloidosis who were the domino liver donors. We also reviewed the literature on case studies of acquired ATTR amyloidosis.

RESULTS

We found amyloid deposition in 13 of our 30 domino liver recipients. A Kaplan-Meier analysis estimated that the median time from DLT to the first detection of amyloid was 8.5 years. In the literature review, the mean time was 7.3 years, with a wide range of 0.5-13 years. Our 7 symptomatic cases and the literature cases with acquired ATTR amyloidosis presented with clinical features that differed from patients with ATTRv amyloidosis who were the domino liver donors. Patients with acquired ATTR amyloidosis showed markedly milder autonomic disturbance, which is one of the main symptoms of ATTRv amyloidosis.

CONCLUSIONS

Careful monitoring is required for DLT recipients of ATTRv liver grafts because the time from DLT to disease onset has a wide range and the clinical picture of these DLT recipients is distinct from that of liver donors.

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.

Amyloid seeding of transthyretin by ex vivo cardiac fibrils and its inhibition

Each of the 30 human amyloid diseases is associated with the aggregation of a particular precursor protein into amyloid fibrils. In transthyretin amyloidosis (ATTR), mutant or wild-type forms of the serum carrier protein transthyretin (TTR), synthesized and secreted by the liver, convert to amyloid fibrils deposited in the heart and other organs. The current standard of care for hereditary ATTR is liver transplantation, which replaces the mutant TTR gene with the wild-type gene. However, the procedure is often followed by cardiac deposition of wild-type TTR secreted by the new liver. Here we find that amyloid fibrils extracted from autopsied and explanted hearts of ATTR patients robustly seed wild-type TTR into amyloid fibrils in vitro. Cardiac-derived ATTR seeds can accelerate fibril formation of wild-type and monomeric TTR at acidic pH and under physiological conditions, respectively. We show that this seeding is inhibited by peptides designed to complement structures of TTR fibrils. These inhibitors cap fibril growth, suggesting an approach for halting progression of ATTR.

Amyloid Polyneuropathy and Myocardial Amyloidosis 10 Years after Domino Liver Transplantation from a Patient with a Transthyretin Ser50Arg Mutation

A 54-year-old man with polycystic liver disease received a domino liver transplantation (DLT) from a patient of hereditary ATTR amyloidosis with the transthyretin Ser50Arg mutation. Ten years after transplantation, he felt a slight numbness in his toes, and cardiac amyloidosis was simultaneously suspected upon a heart function evaluation. Biopsy specimens from the myocardium revealed transthyretin amyloidosis with the Ser50Arg mutation. Oral tafamidis therapy has inhibited the progression of neurological and cardiovascular symptoms this far. We herein report this first case of amyloid polyneuropathy and myocardial amyloidosis after DLT from hereditary ATTR amyloidosis with a transthyretin Ser50Arg mutation and discuss similar cases of other mutations.

Early skin denervation in hereditary and iatrogenic transthyretin amyloid neuropathy

Objective:

To elucidate early skin denervation in hereditary transthyretin (TTR) amyloidosis and iatrogenic TTR amyloidosis.

Methods:

We investigated intraepidermal nerve fiber density (IENFD) and clinical findings in 32 patients with hereditary TTR amyloidosis, 11 asymptomatic mutation carriers, 6 patients with iatrogenic TTR amyloidosis, and 23 healthy volunteers.

Results:

IENFD values were reduced in patients with the V30M mutation (1.9 ± 2.1 per 1 mm), patients with non-V30M mutations (5.8 ± 3.2 per 1 mm), and patients with iatrogenic TTR amyloidosis (3.5 ± 1.8 per 1 mm) compared with healthy volunteers (11.8 ± 3.2 per 1 mm) (p < 0.01). Skin denervation also occurred, even in presymptomatic V30M mutation carriers (5.0 ± 2.2 per 1 mm). The IENFD was correlated with disease duration (ρ = −0.533, p = 0.002) and various peripheral neuropathy parameters such as sensory impairment in the Kumamoto clinical score (ρ = −0.575, p = 0.001), heat-pain detection threshold (ρ = −0.704, p < 0.001), and sural sensory nerve action potential (ρ = 0.481, p = 0.005). TTR amyloid deposits frequently occurred in connective tissues and vessels of the dermal reticular layer in patients with hereditary TTR amyloidosis and those with iatrogenic TTR amyloidosis.

Conclusions:

Patients with hereditary TTR amyloidosis and those with iatrogenic TTR amyloidosis may show early skin denervation even in the presymptomatic stage. IENFD may thus be useful for early diagnosis and may serve as a biomarker in clinical trials for hereditary and iatrogenic TTR amyloidosis.

Genetic, hematological, and immunological disorders transmissible with liver transplantation

It is well recognized that solid organ transplantation can transmit bacterial infection and chronic viral hepatitis as well as certain cancers. As indications for liver transplantation (LT) have expanded, it has been used to treat and even cure certain genetic cholestatic disorders, urea cycle defects, and coagulation abnormalities; many of these conditions are potentially transmissible with LT as well. It is important for clinicians and transplant patients to be aware of these potentially transmissible conditions as unexplained post-LT complications can sometimes be related to donor transmission of disease and thus should prompt a thorough exploration of the donor allograft history. Herein, we will review the reported genetic, metabolic, hematologic, and immunological disorders that are transmissible with LT and describe clinical scenarios in which these cases have occurred, such as in inadvertent or recognized transplantation of a diseased organ, domino transplantation, and with living related liver donation. Liver Transplantation 23 663-678 2017 AASLD.

Addressing Common Questions Encountered in the Diagnosis and Management of Cardiac Amyloidosis

Advances in cardiac imaging have resulted in greater recognition of cardiac amyloidosis in everyday clinical practice, but the diagnosis continues to be made in patients with late-stage disease, suggesting that more needs to be done to improve awareness of its clinical manifestations and the potential of therapeutic intervention to improve prognosis. Light chain cardiac amyloidosis, in particular, if recognized early and treated with targeted plasma cell therapy, can be managed very effectively. For patients with transthyretin amyloidosis, there are numerous therapies that are currently in late-phase clinical trials. In this review, we address common questions encountered in clinical practice regarding etiology, clinical presentation, diagnosis, and management of cardiac amyloidosis, focusing on recent important developments in cardiac imaging and biochemical diagnosis. The aim is to show how a systematic approach to the evaluation of suspected cardiac amyloidosis can impact the prognosis of patients in the modern era.

Iatrogenic amyloid polyneuropathy after domino liver transplantation

Liver transplantation has been used in treatment of transthyretin amyloidosis, and some patients undergo domino liver transplantation (DLT) with explanted liver being transplanted to another patient with liver failure as the liver is otherwise usually functionally normal. Until end of 2015, there were 1154 DLT performed worldwide. DLT for transthyretin amyloidosis is associated with the risk of developing de novo systemic amyloidosis and amyloid neuropathy, and the risk may be greater with some non-Val30Met mutations. De novo amyloid neuropathy has been described in up to 23% of transplant recipients. Neuropathy may be preceded by asymptomatic amyloid deposition in various tissues and symptoms of neuropathy started after a median of 7 years following DLT (5.7 ± 3.2 years; range 2 mo to 10 years). Typical initial symptoms include neuropathic pain and sensory loss, while dysautonomia usually starts later. Progression of neuropathy may necessitate liver re-transplantation, and subsequent improvement of neuropathy has been reported in some patients. Explant allograft recipients need close monitoring for signs of systemic amyloidosis, neuropathy and dysautonomia as progressive symptoms may require re-transplantation.

Rapidly Progressive Transthyretin-Mediated Amyloidosis in a Domino Liver Transplant Recipient of a Ser23Asn Donor

Domino liver transplantation, in which the liver of a patient with transthyretin-mediated amyloidosis is transplanted into another patient, has been an established procedure performed at several centers across the world. The risk of developing systemic amyloidosis in transthyretin-mediated amyloidosis liver transplant recipients is a topic of ongoing investigation. We report a case of rapidly progressive transthyretin amyloidosis in a patient who received a liver from a donor with a rare Ser23Asn mutation. We advise exercising caution when considering domino liver transplantation in patients with this particular mutation.

Amyloid fibril proteins and amyloidosis: chemical identification and clinical classification International Society of Amyloidosis 2016 Nomenclature Guidelines

The Nomenclature Committee of the International Society of Amyloidosis (ISA) met during the XVth Symposium of the Society, 3 July-7 July 2016, Uppsala, Sweden, to assess and formulate recommendations for nomenclature for amyloid fibril proteins and the clinical classification of the amyloidoses. An amyloid fibril must exhibit affinity for Congo red and with green, yellow or orange birefringence when the Congo red-stained deposits are viewed with polarized light. While congophilia and birefringence remain the gold standard for demonstration of amyloid deposits, new staining and imaging techniques are proving useful. To be included in the nomenclature list, in addition to congophilia and birefringence, the chemical identity of the protein must be unambiguously characterized by protein sequence analysis when possible. In general, it is insufficient to identify a mutation in the gene of a candidate amyloid protein without confirming the variant changes in the amyloid fibril protein. Each distinct form of amyloidosis is uniquely characterized by the chemical identity of the amyloid fibril protein that deposits in the extracellular spaces of tissues and organs and gives rise to the disease syndrome. The fibril proteins are designated as protein A followed by a suffix that is an abbreviation of the parent or precursor protein name. To date, there are 36 known extracellular fibril proteins in humans, 2 of which are iatrogenic in nature and 9 of which have also been identified in animals. Two newly recognized fibril proteins, AApoCII derived from apolipoprotein CII and AApoCIII derived from apolipoprotein CIII, have been added. AApoCII amyloidosis and AApoCIII amyloidosis are hereditary systemic amyloidoses. Intracellular protein inclusions displaying some of the properties of amyloid, "intracellular amyloid" have been reported. Two proteins which were previously characterized as intracellular inclusions, tau and α-synuclein, are now recognized to form extracellular deposits upon cell death and thus have been included in Table 1 as ATau and AαSyn.

Current and Future Treatment Approaches in Transthyretin Familial Amyloid Polyneuropathy

OPINION STATEMENT

Treatment of transthyretin familial amyloid polyneuropathy (TTR FAP) must be tailored to disease stage. Patients with early stage disease (i.e., without major impairment in walking ability), especially younger patients, should be referred as soon as possible for liver transplantation (LT) in the absence of major comorbid conditions. LT remains the most effective treatment option to date and should be offered to these patients as early as possible. Bridging therapy with an oral TTR stabilizer (tafamidis or diflunisal, according to local access to these treatments) should be started as soon as the diagnosis of TTR FAP is established. Early stage patients who do not wish to or have contraindications to LT should be treated with an oral TTR stabilizer or get access to the newly developed therapeutic options (IONIS TTR-Rx, patisiran, doxycycline/TUDCA). Late stage patients (presenting with significant walking impairment) are usually older and notoriously difficult to treat. They should be offered an oral TTR stabilizer but are not candidates for LT due to a significant rate of perioperative complications and increased risk of progressive neurological and especially cardiac disease despite LT. Access to the different therapies in development should also be considered depending on respective inclusion and exclusion criteria. The abovementioned treatment options were mostly validated in Val30Met mutation patients, but should also be offered to non-Val30Met patients, although mortality rates after LT are higher in these patients. Treatment decisions should be made on an individual basis. Screening for heart, eye, and renal involvement is mandatory for every patient at disease diagnosis and regularly thereafter, even in transplanted patients. Symptomatic treatment should be offered as needed, as well as genetic counseling to at-risk family members. Asymptomatic mutation carriers should benefit from regular screening for early symptoms of disease. Current therapeutic management of TTR FAP will hopefully be changed in the near future with data from the ongoing phase 2/3 studies testing the TTR gene silencing agents. In the longer term, it is likely that combined therapeutic approaches will be necessary to reverse the disease process.

Endoplasmic Reticulum Proteostasis Influences the Oligomeric State of an Amyloidogenic Protein Secreted from Mammalian Cells

Transthyretin (TTR) is a tetrameric serum protein associated with multiple systemic amyloid diseases. In these disorders, TTR aggregates in extracellular environments through a mechanism involving rate-limiting dissociation of the tetramer to monomers, which then misfold and aggregate into soluble oligomers and amyloid fibrils that induce toxicity in distal tissues. Using an assay established herein, we show that highly destabilized, aggregation-prone TTR variants are secreted as both native tetramers and non-native conformations that accumulate as high-molecular-weight oligomers. Pharmacologic chaperones that promote endoplasmic reticulum (ER) proteostasis of destabilized TTR variants increase their fraction secreted as a tetramer and reduce extracellular aggregate populations. In contrast, disrupting ER proteostasis reduces the fraction of destabilized TTR secreted as a tetramer and increases extracellular aggregates. These results identify ER proteostasis as a factor that can affect conformational integrity and thus toxic aggregation of secreted amyloidogenic proteins associated with the pathology of protein aggregation diseases.

Current and future treatment of amyloid diseases

There are more than 30 human proteins whose aggregation appears to cause degenerative maladies referred to as amyloid diseases or amyloidoses. These disorders are named after the characteristic cross-β-sheet amyloid fibrils that accumulate systemically or are localized to specific organs. In most cases, current treatment is limited to symptomatic approaches and thus disease-modifying therapies are needed. Alzheimer's disease is a neurodegenerative disorder with extracellular amyloid β-peptide (Aβ) fibrils and intracellular tau neurofibrillary tangles as pathological hallmarks. Numerous clinical trials have been conducted with passive and active immunotherapy, and small molecules to inhibit Aβ formation and aggregation or to enhance Aβ clearance; so far such clinical trials have been unsuccessful. Novel strategies are therefore required and here we will discuss the possibility of utilizing the chaperone BRICHOS to prevent Aβ aggregation and toxicity. Type 2 diabetes mellitus is symptomatically treated with insulin. However, the underlying pathology is linked to the aggregation and progressive accumulation of islet amyloid polypeptide as fibrils and oligomers, which are cytotoxic. Several compounds have been shown to inhibit islet amyloid aggregation and cytotoxicity in vitro. Future animal studies and clinical trials have to be conducted to determine their efficacy in vivo. The transthyretin (TTR) amyloidoses are a group of systemic degenerative diseases compromising multiple organ systems, caused by TTR aggregation. Liver transplantation decreases the generation of misfolded TTR and improves the quality of life for a subgroup of this patient population. Compounds that stabilize the natively folded, nonamyloidogenic, tetrameric conformation of TTR have been developed and the drug tafamidis is available as a promising treatment.

Mechanism of Action and Clinical Application of Tafamidis in Hereditary Transthyretin Amyloidosis

Transthyretin (TTR) transports the retinol-binding protein-vitamin A complex and is a minor transporter of thyroxine in blood. Its tetrameric structure undergoes rate-limiting dissociation and monomer misfolding, enabling TTR to aggregate or to become amyloidogenic. Mutations in the TTR gene generally destabilize the tetramer and/or accelerate tetramer dissociation, promoting amyloidogenesis. TTR-related amyloidoses are rare, fatal, protein-misfolding disorders, characterized by formation of soluble aggregates of variable structure and tissue deposition of amyloid. The TTR amyloidoses present with a spectrum of manifestations, encompassing progressive neuropathy and/or cardiomyopathy. Until recently, the only accepted treatment to halt progression of hereditary TTR amyloidosis was liver transplantation, which replaces the hepatic source of mutant TTR with the less amyloidogenic wild-type TTR. Tafamidis meglumine is a rationally designed, non-NSAID benzoxazole derivative that binds with high affinity and selectivity to TTR and kinetically stabilizes the tetramer, slowing monomer formation, misfolding, and amyloidogenesis. Tafamidis is the first pharmacotherapy approved to slow the progression of peripheral neurologic impairment in TTR familial amyloid polyneuropathy. Here we describe the mechanism of action of tafamidis and review the clinical data, demonstrating that tafamidis treatment slows neurologic deterioration and preserves nutritional status, as well as quality of life in patients with early-stage Val30Met amyloidosis.

Recipient aging accelerates acquired transthyretin amyloidosis after domino liver transplantation

Domino liver transplantation (DLT) with liver grafts from patients with hereditary transthyretin (TTR) amyloidosis has been performed throughout the world because of a severe liver graft shortage. Reports of acquired systemic TTR amyloidosis in domino liver recipients have been increasing; however, the precise pathogenesis and clinical course of acquired TTR amyloidosis remains unclear. We analyzed the relationship between the occurrence of acquired amyloidosis and clinical features in 22 consecutive domino liver donors with hereditary TTR amyloidosis (10 males and 12 females; mean age at DLT: 37.2 years; TTR mutations: V30M [n = 19], Y114C [n = 1], L55P [n = 1], and S50I [n = 1]) and 22 liver recipients (16 males and 6 females; mean age at DLT, 46.2 years). The mean times from DLT to amyloid first appearance and transplant recipient symptom onset were 8.2 years and 9.9 years, respectively. Kaplan-Meier analysis and quantification of the amyloid deposition revealed aging of recipients correlated with early de novo amyloid deposition. The sex of donors and recipients and the age, disease duration, and disease severity of donors had no significant effect on the latency of de novo amyloid deposition. In conclusion, our results demonstrate that recipient aging is associated with the early onset de novo amyloidosis. Because acquired amyloidosis will likely increase, careful follow-up for early amyloidosis detection and new treatments, including TTR stabilizers and gene-silencing therapies, are required. Liver Transplantation 22 656-664 2016 AASLD.

Long-term Results of Domino Liver Transplantation for Hepatocellular Carcinoma Using the "Double Piggy-back" Technique: A 13-Year Experience

OBJECTIVES

The aim of this study was to evaluate the long-term outcome of liver transplantation (LT) for hepatocellular carcinoma (HCC) with Domino LT (DLT) using the "Double Piggy-back" technique.

BACKGROUND DATA

DLT using livers from familial amyloidotic polyneuropathy (FAP) patients is a well-described technique and useful for expanding the donor pool. However, data on long-term results for HCC are limited, particularly regarding the use of the "Double Piggy-back" technique.

METHODS

Between 2001 and 2014, a total of 260 patients undergoing LT for HCC were analyzed from a prospective database. Of those, 114 were submitted to DLT. Comparisons between groups were performed using propensity score matching.

RESULTS

Median follow-up was 34 months (1-152). Overall and disease-free 5-year survival rates for the whole population were 58% and 56%, respectively. There were 177 (68%) patients within Milan Criteria and an additional 26 (10%) within University of California San Francisco (UCSF) criteria. Patients older than 50 years were more likely to receive an FAP liver [odds ratio (OR) 1.94, confidence interval (CI) 1.02-3.69]. DLT patients had more major complications (23.7% vs 13.0%, P = 0.025). Only patients undergoing DLT presented with piggy-back syndrome (7% vs 0%, P = 0.001). After adjusting for potential confounders, DLT and cadaveric LT had a similar 5-year survival rate (59% vs 44%, respectively, P = 0.117). Thirteen patients (11.4%) evidenced FAP disease but not before 6 years after DLT.

CONCLUSIONS

DLT for HCC is feasible and achieves equivalent results to cadaveric LT. The benefit of expanding the donor pool must be balanced against higher morbidity and a real risk of disease transmission.

The pathological and biochemical identification of possible seed-lesions of transmitted transthyretin amyloidosis after domino liver transplantation

The most serious issue in domino liver transplantation (DLT) using liver grafts from patients with transthyretin (TTR)‐related familial amyloid polyneuropathy (FAP) is the development of iatrogenic transmitted amyloidosis (de novo amyloidosis) in DLT‐recipients. However, little is known regarding the mechanisms of the initial stage of amyloid formation in these recipients. We detected initial lesions (possible seed‐lesions) of this iatrogenic amyloidosis in two recipients following liver grafting from FAP patients. Patient 1 underwent DLT at age 65 from an FAP patient with a Val30Met TTR variant and patient 2 received DLT from an FAP patient with a Val30Leu TTR variant at age 32. Patient 2 was started on diflunisal administration from 4 years after DLT. While neither patient had symptoms of FAP, small amyloid deposits were detected on the gastroduodenal mucosae 14 months and 12 years after DLT in patient 1 and patient 2, respectively. The amyloid was analyzed using a laser microdissection system and tandem mass spectrometry. Biochemical analysis indicated that the amyloid was composed mostly of variant TTR produced from the transplanted liver in both patients. In patient 1, wild‐type TTR amyloid was detectable in the duodenal mucosa obtained 2 years after DLT. This is the first study to successfully capture the pathological and biochemical features of initial‐stage amyloid lesions in DLT recipients. The findings clearly indicate that amyloid deposition can start by deposition of variant TTR followed by deposition of wild‐type TTR, and blocking of amyloid seed formation from variant TTR may be a key to prevent or delay the development of DLT‐associated amyloidosis.

Liver retransplantation in patients with acquired familial amyloid polyneuropathy: a Portuguese center experience

In 1995 Furtado et al performed the first domino transplantation using a donor liver with familial amyloid polyneuropathy (FAP), thereby increasing the pool of donors. Our experience showed that the onset of FAP symptoms occurs earlier in some patients. Patients with FAP acquired by transplantation are candidates for liver retransplantation to minimize the progression of symptoms. Liver retransplantation is considered to be a high-risk procedure and has lower survival compared with the first transplantation. We evaluated the risk of liver retransplantation in patients with acquired FAP. We did a retrospective analysis of these patients based on the records of perioperative data. From 1995 to 2004 we carried out 81 domino transplantations, of which 10 were submitted to liver retransplantation because of acquired FAP. The better outcomes in this group lead us to think that the liver retransplantation in patients with acquired FAP is not associated with the same risks of liver retransplantation in candidates with graft failure.

Liver Transplantation for Hereditary Transthyretin Amyloidosis: After 20 Years Still the Best Therapeutic Alternative?

BACKGROUND

Until recently, liver transplantation (Ltx) was the only available treatment for hereditary transthyretin (TTR) amyloidosis; today, however, several pharmacotherapies are tested. Herein, we present survival data from the largest available database on transplanted hereditary TTR patients to serve as a base for comparison.

METHODS

Liver transplantation was evaluated in a 20-year retrospective analysis of the Familial Amyloidosis Polyneuropathy World Transplant Registry.

RESULTS

From April 1990 until December 2010, data were accumulated from 77 liver transplant centers. The Registry contains 1940 patients, and 1379 are alive. Eighty-eight Ltx were performed in combination with a heart and/or kidney transplantation. Overall, 20-year survival after Ltx was 55.3%. Multivariate analysis revealed modified body mass index, early onset of disease (<50 years of age), disease duration before Ltx, and TTR Val30Met versus non-TTR Val30Met mutations as independent significant survival factors. Early-onset patients had an expected mortality rate of 38% that of the late-onset group (P < 0.001). Furthermore, Val30Met patients had an expected mortality rate of 61% that of non-TTR Val30Met patients (P < 0.001). With each year of duration of disease before Ltx, expected mortality increased by 11% (P < 0.001). With each 100-unit increase in modified body mass index at Ltx, the expected mortality decreased to 89% of the expected mortality (P < 0.001). Cardiovascular death was markedly more common than that observed in patients undergoing Ltx for end-stage liver disease.

CONCLUSIONS

Long-term survival after Ltx, especially for early-onset TTR Val30Met patients, is excellent. The risk of delaying Ltx by testing alternative treatments, especially in early-onset TTR Val30Met patients, requires consideration.

[Amyloidosis and neurological disorders: Treatable amyloidosis]

In neurological disorder related amyloidosis, several therapies have been developed in the recent decade. In AL and AA amyloidosis, novel chemotherapy and IL6 receptor antibody have been found to be effective, respectively. In addition to these amyloidosis, in transthyretin (TTR) related familial amyloidotic polyneuropathy (FAP), liver transplantation, tertial structure stabilizing drugs, and gene silencing drugs have been developing now. As neurological disorder related amyloidosis, systemic amyloidosis, such as AL amyloidosis, AA amyloidosis, dialysis related amyloidosis, FAP, senile systemic amyloidosis, and brain localized amyloidosis, such as Alzheimer's disease, and prion disease are listed. In this review, we mentioned diagnosis, pathogenesis and therapies of systemic amyloidosis.

Transthyretin Amyloidosis: Chaperone Concentration Changes and Increased Proteolysis in the Pathway to Disease

Transthyretin amyloidosis is a conformational pathology characterized by the extracellular formation of amyloid deposits and the progressive impairment of the peripheral nervous system. Point mutations in this tetrameric plasma protein decrease its stability and are linked to disease onset and progression. Since non-mutated transthyretin also forms amyloid in systemic senile amyloidosis and some mutation bearers are asymptomatic throughout their lives, non-genetic factors must also be involved in transthyretin amyloidosis. We discovered, using a differential proteomics approach, that extracellular chaperones such as fibrinogen, clusterin, haptoglobin, alpha-1-anti-trypsin and 2-macroglobulin are overrepresented in transthyretin amyloidosis. Our data shows that a complex network of extracellular chaperones are over represented in human plasma and we speculate that they act synergistically to cope with amyloid prone proteins. Proteostasis may thus be as important as point mutations in transthyretin amyloidosis.

The transthyretin amyloidoses: advances in therapy

There are two forms of transthyretin (TTR) amyloidosis: non-hereditary and hereditary. The non-hereditary form (ATTRwt) is caused by native or wild-type TTR and was previously referred to as senile systemic amyloidosis. The hereditary form (ATTRm) is caused by variant TTR which results from a genetic mutation of TTR. The predominant effect of ATTRwt amyloidosis is on the heart, with patients having a greater left ventricular wall thickness at presentation than the devastating form which is light chain (AL) amyloidosis. ATTRm amyloidosis is broadly split into two categories: a type that predominantly affects the nervous system (often called familial amyloid polyneuropathy (FAP)) and one with a predilection for the heart (often called familial amyloid cardiomyopathy (FAC)). Approximately half of all TTR mutations known to express a clinical phenotype cause a cardiomyopathy. Since the introduction of orthotopic liver transplantation for ATTRm amyloidosis in 1991, several additional therapies have been developed. These therapies aim to provide a reduction or elimination of TTR from the plasma (through genetic approaches), stabilisation of the TTR molecule (to prevent deposition) and dissolution of the amyloid matrix. We describe the latest developments in these approaches to management, many of which are also applicable to wild-type amyloidosis.