Early liver transplantation improves familial amyloidotic polyneuropathy patients' survival

Real life experience of tafamidis for the treatment of Spanish patients with Val30Met transthyretin amyloidosis with polyneuropathy

INTRODUCTION

Tafamidis is the only approved transthyretin stabiliser approved for the treatment of variant transthyretin amyloidosis (A-ATTRv) related polyneuropathy (PNP). The aim of this study is to analyse the effectiveness of tafamidis in a real-world setting in Spain.

METHODS

This is a national multicenter study in which patients with V30M A-ATTR related PN treated with tafamidis for at least 1 year were included. Clinical, demographic, analytical and neurophysiological variables were analysed.

RESULTS

100 patients were recruited. Overall, 47 patients (47%) were classified as complete responders, 32 (32%) as partial responders and 21 (21%) as non-responders. The median duration of treatment with tafamidis was 35 months. Better treatment response was shown in patients with in polyneuropathy disability score (PND) I, lower neuropathy impairment score (NIS), compound muscle action potential (CMAP) and Norfolk QoL questionnaire. Higher albumin levels and lower NTproBNP levels were also associated with better treatment response. A basal NIS≥15 predicts that the patient could be a non-responder with a 60% probability.

CONCLUSIONS

Our results reinforce the tafamidis efficacy to treat A-ATTRv-PNP if started early in the disease course. Patients with the V30M variant, NIS<15 and PND I are the most appropriate subjects for this treatment.

A narrative review and expert recommendations on the assessment of the clinical manifestations, follow-up, and management of post-OLT patients with ATTRv amyloidosis

Orthotopic liver transplantation (OLT) was the first treatment able to modify the natural course of hereditary transthyretin (ATTRv) amyloidosis, which is a rare and fatal disorder caused by the accumulation of misfolded transthyretin (TTR) variants in different organs and tissues and which leads to a progressive and multisystem dysfunction. Because the liver is the main source of TTR, OLT dramatically reduces the production of the pathogenic TTR variant, which should prevent amyloid formation and halt disease progression. However, amyloidosis progression may occur after OLT due to wild-type TTR deposition, especially in the nerves and heart. In this review, we discuss the disease features influencing OLT outcomes and the clinical manifestations of ATTRv amyloidosis progression post-OLT to improve our understanding of disease worsening after OLT and optimize the follow-up and clinical management of these patients. By conducting a literature review on the PubMed database, we identified patient characteristics that have been associated with worse post-OLT outcomes, including late-onset V50M and non-V50M variants, age >40 years, long disease duration, advanced neuropathy and autonomic dysfunction, and malnutrition. Regarding post-OLT mortality, deaths occurring within the first year after OLT were mainly associated with fatal graft complications and infectious diseases, whereas cardiovascular-related deaths usually occurred later. Considering the diverse clinical manifestations of ATTRv amyloidosis progression post-OLT, including worsening neuropathy and/or cardiomyopathy, autonomic dysfunction, and oculoleptomeningeal involvement, we present advice on the most relevant tests for assessing disease progression post-OLT. Finally, we discuss the use of new therapies based on TTR stabilizers and TTR mRNA silencers for the treatment of ATTRv amyloidosis patients post-OLT.

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).

Small gauge vitrectomy for vitreous amyloidosis and subsequent management of secondary glaucoma in patients with hereditary transthyretin amyloidosis

We conducted a retrospective observational study including 31 eyes of 20 patients in order to investigate the efficacy of 25-gauge vitrectomy for vitreous opacity with minimal conjunctival invasion and subsequent management of intraocular pressure (IOP) secondary to hereditary transthyretin amyloidosis. We followed up these patients for an average of 44.7 ± 32.6 months. The primary outcome was best corrected visual acuity (BCVA) at 1 month after surgery and at the final follow-up visit, with management of subsequent IOP elevation. Secondary outcomes included the post-vitrectomy IOP survival rate, to determine the frequency of IOP elevation requiring glaucoma surgery. Mean age at vitrectomy was 55.4 ± 9.1 years. Logarithm of the Minimum Angle of Resolution (LogMAR) BCVA showed immediate improvement from 0.73 ± 0.62 to 0.00 ± 0.22 at 1 month (p = 4.1 × 10⁻⁷), an improvement that was maintained up to the final follow-up visit, when IOP was maintained at 13.1 ± 5.2 mmHg. The survival rate of post-vitrectomy IOP control was 0.51, 0.38, and 0.23 at 12, 24, and 60 months, respectively. A poor post-vitrectomy IOP survival rate suggests that removing vitreous amyloid via 25-gauge vitrectomy is not sufficient to guarantee good visual function; subsequent careful follow-up and proper glaucoma management is also required in order to achieve this goal.

Recent Advances in Oligonucleotide-Based Therapy for Transthyretin Amyloidosis: Clinical Impact and Future Prospects

Transthyretin (TTR) amyloidosis, also known as transthyretin-related familial amyloidotic polyneuropathy (ATTR-FAP), is a fatal hereditary systemic amyloidosis caused by mutant forms of TTR. Although conventional treatments for ATTR-FAP, such as liver transplantation (LT) and TTR tetramer stabilizer, reportedly halt the progression of clinical manifestation, these therapies have several limitations. Oligonucleotide-based therapy, e.g. small interfering RNA (siRNA)- and antisense oligonucleotides (ASOs)-based therapy, hold enormous potential for the treatment of intractable diseases such as ATTR-FAP, by specifically regulating the gene responsible for the disease. Clinical evidence strongly suggests that LT inhibits mutant TTR production, thus improving the manifestation of ATTR-FAP. Therefore, an oligonucleotide-based therapy for ATTR-FAP, which reduces the production of TTR by the liver, has recently been developed in preclinical and clinical studies. This review focuses on recent advances in oligonucleotide-based therapy and future prospects of next-generation oligonucleotide-based drugs for therapeutic use against ATTR-FAP.

Method-of-limits; Cold and warm perception thresholds at proximal and distal body regions

•

High correlation between thermal thresholds and age at the dorsal foot.

•

Reference values at eight different test sites.

•

Reference values at various proximal and distal sites in the upper and lower extremities.

Objective

Thermal quantitative sensory testing with the ‘Method-of-Limits’ is an established rationale for detection of small nerve fiber dysfunction, but adequate reference values are crucial for such evaluations, regardless of the underlying cause. This study assessed reference data for cold- (CPT) and warm- (WPT) perception thresholds at both proximal and distal sites in eight body regions of the lower and upper extremities, all determined within the same test session for each subject.

Methods

Seventy-five healthy subjects (aged 16–72 years) were tested according to the method-of-limit for CPT and WPT at the dorsum of the foot, the medial and lateral lower leg, the ventral thigh, the thenar eminence, the radial and ulnar part of the lower arm, and the anterior deltoid part of the upper arm.

Results

Overall, thermal perception thresholds (TPT) varied with test location, but were higher in the lower than in the upper part of the body, also WPT were generally higher than CPT. TPT at the dorsum foot highly correlated with age, while inconsistent correlations were noted between TPT and age or height at other tested locations.

Conclusion

This study describes for the first time reference values at eight defined body regions, at both proximal and distal sites.

Significance

The report enables refined evaluations of general small nerve fiber function, as assessed by quantitative thermal sensory testing with the Method-of-Limits.

Outcomes of Patients With Familial Transthyretin Amyloidosis After Liver Transplantation

BACKGROUND

Familial transthyretin amyloidosis is a disease caused by misfolded transthyretin aggregates that can impair multiple organ systems. Liver transplantation is the first-line treatment for familial transthyretin amyloidosis.

RESEARCH QUESTION

Our objective is to study outcomes and survival among patients with familial transthyretin amyloidosis after transplantation.

DESIGN

All patients undergoing orthotopic liver transplant for familial transthyretin amyloidosis at Mayo Clinic between 1997 and 2012 were reviewed. Baseline clinical characteristics, organs transplanted, and posttransplant clinical course were assessed.

RESULTS

Of the 40 patients, 7 patients had the V30M mutation and 33 had other mutations. Nineteen patients received liver only, 19 liver and heart, and 2 combined liver, heart, and kidney transplants. The 5-year overall survival was 85% for those receiving multiple organ transplant and 52% for those receiving liver transplant only ( P = .057). There was no difference in overall survival based on mutation (V30M vs other mutations), but survival was confounded by varied disease involvement and organs transplanted. Those who had early death (≤24 months from liver transplant) had a higher incidence of baseline peripheral neuropathy, autonomic neuropathy, lower modified BMI, and higher alkaline phosphatase.

DISCUSSION

Outcomes of orthotopic liver transplant in familial transthyretin amyloidosis are variable due to heterogeneity in mutations and patient status at the time of transplant. Familial transthyretin amyloidosis can progress, despite liver transplantation. Patients receiving combined liver, heart/kidney transplant demonstrated improved survival compared to liver transplant alone.

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.

Progression of myocardial sympathetic denervation assessed by 123I-MIBG imaging in familial amyloid polyneuropathy and the effect of liver transplantation

INTRODUCTION

Familial amyloid polyneuropathy (FAP) is a rare disease caused by systemic deposition of amyloidogenic variants of the transthyretin (TTR) protein. The TTR-V30M mutation is caused by the substitution of valine by methionine at position 30 and mainly affects the peripheral and autonomic nervous systems. Cardiovascular manifestations are common and are due to autonomic denervation and to amyloid deposition in the heart. Cardiac sympathetic denervation detected by iodine-123 labeled metaiodobenzylguanidine (MIBG) is an important prognostic marker in TTR-V30M FAP. Liver transplantation, widely used to halt neurological involvement, appears to have a varying effect on the progression of amyloid cardiomyopathy. Its effect on the progression of cardiac denervation remains unknown.

METHODS

In this observational study, patients with the TTR-V30M mutation underwent annual cardiac assessment and serial MIBG imaging with quantification of the late heart-to-mediastinum (H/M) ratio.

RESULTS

We studied 232 patients (median age 40 years, 54.7% female, 37.9% asymptomatic at the time of inclusion) who were followed for a median of 4.5 years and underwent a total of 558 MIBG scans. During follow-up, 47 patients (20.3%) died. MIBG scintigraphy at inclusion was a strong predictor of prognosis, with the risk of death increasing by 27.8% for each one-tenth reduction in the late H/M ratio. The late H/M ratio decreased with age (0.082/year, p<0.001), but progression of cardiac denervation was so slow that annual repetition of MIBG imaging did not increase its prognostic accuracy. During follow-up, 70 symptomatic patients underwent liver transplantation. The late H/M ratio decreased by 0.19/year until transplantation but no statistically significant differences were detected after the procedure.

CONCLUSIONS

Cardiac denervation is common during the progression of TTR-V30M FAP and quantification of the late H/M ratio on MIBG scintigraphy is valuable for prognostic stratification of these patients. Liver transplantation stabilizes cardiac denervation, without recovery or further deterioration in cardiac MIBG uptake after the procedure.

Perioperative Predictors of Survival After Liver Transplantation for Familial Amyloid Polyneuropathy in a Portuguese Center

BACKGROUND

Liver transplantation (LT) has been the treatment of choice to halt the progression of familial amyloid polyneuropathy (FAP). Few studies have identified prognostic factors for post-LT survival in FAP. Our aim was to assess survival rate and to identify independent factors for survival after LT.

METHODS

This retrospective cohort study of FAP patients transplanted for the first time analyzed 116 transplantations from 2006 to 2014. The median follow-up period was 45.5 months.

RESULTS

The overall survival rates at 1 month, 1 year, and 5 years were 89%, 82% and 79%, respectively. On multivariate analysis, only number of red blood cell (RBC) units transfused during surgery, operation time, and body mass index were independent prognostic factors for patient survival. Only 30% of patients were transfused during surgery, and, in these, each RBC unit transfused increased mortality by 53%. The operation time increased mortality by 20% for every 15 minutes of surgery.

CONCLUSIONS

This study suggests that operation time and RBC transfused are predominant factors affecting post-LT survival in our FAP patients.

Clinical measures in transthyretin familial amyloid polyneuropathy

INTRODUCTION

This observational, cross-sectional, single-center study aimed to identify instruments capable of measuring disease progression in transthyretin familial amyloid polyneuropathy (TTR-FAP).

METHODS

The relationship between disease stage and Neuropathy Impairment Score-Lower Limbs (NIS-LL) and Norfolk Quality of Life-Diabetic Neuropathy (Norfolk QOL-DN) total score was assessed in 61 (stages 1-3) patients with TTR-FAP (V30M variant) and 16 healthy controls. Composite measures of large- and small-nerve fiber function, and modified body mass index (mBMI) were also assessed.

RESULTS

Ordinal-based NIS-LL and Norfolk QOL-DN scores discriminated between disease stages (P < 0.0001 for NIS-LL and Norfolk QOL-DN). Longer disease duration correlated with worse NIS-LL and Norfolk QOL-DN. Karnofsky performance score declined progressively by disease stage. Composite measures of nerve fiber function differentiated stage 1 from stage 2 disease. The mBMI declined with advancing disease.

CONCLUSIONS

NIS-LL, Norfolk QOL-DN score, composite endpoints of nerve fiber function, and mBMI are valid, reliable measures of TTR-FAP severity. Muscle Nerve 55: 323-332, 2017.

Survival After Transplantation in Patients With Mutations Other Than Val30Met: Extracts From the FAP World Transplant Registry

Background

Liver transplantation (LTx) has been performed for hereditary transthyretin amyloidosis (ATTR) since 1990. Outcomes for a relatively large series of LTx ATTR patients with the Val30Met (mutation are available, but for non-Val30Met patients, only a few reports with a small number of patients exist. Here, we present outcomes for non-Val30Met ATTR patients after LTx, as reported to the Familial Amyloid Polyneuropathy World Transplant Registry (FAPWTR).

Methods

Data regarding outcome were extracted for all non-Val30Met patients reported to the registry. Survival rates were analyzed by the Kaplan-Meier method and log-rank test.

Results

The total number of patients with a non-Val30Met mutation in the registry was 264 (174 men and 90 women), representing 57 mutations. The 10-year survival varied markedly for the 9 most common mutations, ranging from 21% for Ser50Arg to 85% for Val71Ala. Poor survival was noted for all mutations with leptomeningeal complications except for those with the Tyr114Cys mutation.

Conclusions

Large differences in survival were observed relative to different mutations and between mutations with similar phenotypes. Excellent survival was noted for mutations, such as Leu111Met, Val71Ala, and Leu58His. Patients with mutations other than Val30Met are not a homogeneous group, and the term non-Val30Met should be used with caution or avoided. Moreover, for several mutations, data are too limited to allow evaluation of the efficacy of LTx, and continuous international collaboration is important for obtaining treatment guidance.

Long-term outcome of patients with hereditary transthyretin V30M amyloidosis with polyneuropathy after liver transplantation

BACKGROUND

Liver transplantation halts production of mutated transthyretin (TTR), and thus it is an accepted treatment, with improved survival, in patients with hereditary (familial) amyloidosis with polyneuropathy (FAP). However, the effects of transplantation on the clinical manifestations of FAP have not yet been adequately clarified. This study aimed to investigate whether liver transplantation would improve the long-term clinical manifestations in FAP patients who had undergone transplantations.

PATIENTS AND METHODS

We assessed 29 non-transplant and 36 transplant FAP V30M patients using an FAP clinical scoring system.

RESULTS

The total clinical score of the non-transplant group increased and was significantly correlated with FAP duration; that of the transplant group increased slowly after transplantation. In patients 5 years or more after FAP onset, the total clinical scores of the transplant group were significantly lower than those of the non-transplant group. In the same patients, scores for sensory, motor, autonomic and organ impairments of the transplant group were significantly lower than those of the non-transplant group.

CONCLUSIONS

Liver transplantation had beneficial effects on FAP clinical manifestations in patients with FAP TTR V30M. Liver transplantation should therefore be considered as an effective treatment in the clinical management of patients with FAP TTR V30M.

Representation of illness in Familial Amyloidotic Polyneuropathy Portuguese Association newspaper: A documental study

This study explores illness representations within Familial Amyloidotic Polyneuropathy Portuguese Association newspaper . A content analysis was performed of the issue data using provisional coding related to the conceptual framework of the study. All dimensions of illness representation in Leventhal's Common Sense Model of illness cognitions and behaviors are present in the data and reflect the experience of living with this disease. Understanding how a person living with an hereditary, rare, neurodegenerative illness is important for developing community nursing interventions. In conclusion, we suggest an integration of common sense knowledge with other approaches for designing an intervention program centered on people living with an hereditary neurodegenerative illness, such as familial amyloidotic polyneuropathy.

Therapeutic Oligonucleotides Targeting Liver Disease: TTR Amyloidosis

The liver has become an increasingly interesting target for oligonucleotide therapy. Mutations of the gene encoding transthyretin (TTR), expressed in vast amounts by the liver, result in a complex degenerative disease, termed familial amyloid polyneuropathy (FAP). Misfolded variants of TTR are linked to the establishment of extracellular protein deposition in various tissues, including the heart and the peripheral nervous system. Recent progress in the chemistry and formulation of antisense (ASO) and small interfering RNA (siRNA) designed for a knockdown of TTR mRNA in the liver has allowed to address the issue of gene-specific molecular therapy in a clinical setting of FAP. The two therapeutic oligonucleotides bind to RNA in a sequence specific manner but exploit different mechanisms. Here we describe major developments that have led to the advent of therapeutic oligonucleotides for treatment of TTR-related disease.

Liver transplantation in transthyretin amyloidosis: issues and challenges

Hereditary transthyretin amyloidosis (ATTR) is a rare worldwide autosomal dominant disease caused by the systemic deposition of an amyloidogenic variant of transthyretin (TTR), which is usually derived from a single amino acid substitution in the TTR gene. More than 100 mutations have been described, with V30M being the most prevalent. Each variant has a different involvement, although peripheral neuropathy and cardiomyopathy are the most common. Orthotopic liver transplantation (OLT) was implemented as the inaugural disease-modifying therapy because the liver produces the circulating unstable TTR. In this review, we focus on the results and long-term outcomes of OLT for ATTR after more than 2063 procedures and 23 years of experience. After successful OLT, neuropathy and organ impairment are not usually reversed, and in some cases, the disease progresses. The overall 5-year survival rate is approximately 100% for V30M patients and 59% for non-ATTR V30M patients. Cardiac-related death and septicemia are the main causes of mortality. Lower survival is related to malnutrition, a longer duration of disease, cardiomyopathy, and a later onset (particularly for males). Deposits, which are composed of a mixture of truncated and full-length TTR (type A) fibrils, have been associated with posttransplant myocardial dysfunction. A higher incidence of early hepatic artery thrombosis of the graft has also been documented for these patients. Liver-kidney/heart transplantation is an alternative for patients with advanced renal disease or heart failure. The sequential procedure, in which ATTR livers are reused in patients with liver disease, reveals that neuropathy in the recipient may appear as soon as 6 years after OLT, and ATTR deposits may appear even earlier. Long-term results of trials with amyloid protein stabilizers or disrupters, silencing RNA, and antisense oligonucleotides will highlight the value and limitations of liver transplantation.

Recent advances in transthyretin amyloidosis therapy

Mutant (MT) forms of transthyretin (TTR) cause the most common type of autosomal-dominant hereditary systemic amyloidosis-familial amyloidotic polyneuropathy (FAP). Until 20 years ago, FAP was thought to be an endemic disease, but FAP is known to occur worldwide. To date, more than 130 mutations in the TTR gene have been reported. Genotype-phenotype correlations are seen in FAP, and some variation in clinical presentation is often observed in individual kindreds with the same mutation and even among family members. Of the pathogenic TTR mutations, Val30Met was the first to be identified and is the most frequent known mutation found throughout the world. Studies of patients with FAP amyloidogenic TTR (ATTR) Val30Met documented sensorimotor polyneuropathy, autonomic dysfunction, heart and kidney failure, gastrointestinal tract (GI) disorders, and other symptoms leading to death, usually within 10 years of the onset of disease. Diagnosis is sometimes delayed, especially in patients without a clear family history and typical clinical manifestations, since diagnosis requires various studies and techniques such as histopathology, genetic testing, and mass spectrometry. For treatment of FAP, liver transplantation (LT) reportedly halts the progression of clinical manifestations. Exchange of an FAP patient's diseased liver with a healthy liver causes MT TTR in the body to be replaced by wild-type (WT) TTR. Although clinical evaluations indicated that progression of other clinical symptoms such as peripheral neuropathy, GI symptoms, and renal involvement usually halted after LT in FAP ATTR Val30Met patients, recent studies suggested that LT failed to prevent progression of cardiac amyloidosis in FAP ATTR Val30Met patients after LT, with this failure reportedly being due to continued formation of amyloid that derived mainly from WT TTR secreted from the transplanted non-mutant liver graft. In recent years, many therapeutic strategies have been proposed, and several ongoing therapeutic trials involve, for example, stabilizers of TTR tetramers (tafamidis and diflunisal) and gene therapies to suppress TTR expression (antisense methods and use of small interfering RNAs). These novel therapies may prove to prevent progression of FAP.

Changes in pathological and biochemical findings of systemic tissue sites in familial amyloid polyneuropathy more than 10 years after liver transplantation

OBJECTIVE

To elucidate the long-term effects of liver transplantation (LT) on familial amyloid polyneuropathy (FAP).

METHODS

We investigated clinicopathological and biochemical characteristics of systemic tissues in four autopsied cases of FAP patients surviving more than 10 years after LT and seven autopsied cases without LT. For analysing the truncated form of transthyretin (TTR) in amyloid, we also employed specimens from additional 18 FAP patients.

RESULTS

Several tissue sites such as the heart, tongue and spinal cord had moderate-to-severe amyloid deposits but other tissues showed no or mild amyloid deposition. Those findings seemed similar to those observed in senile systemic amyloidosis (SSA), a sporadic amyloidosis caused by wild-type (WT) TTR. Also, amyloid deposits in systemic tissue sites except for the spinal cord in patients after LT derived mostly from WT TTR secreted from the normal liver grafts. In addition, in non-transplantation patients, proportions of WT TTR seemed to be relatively high in those tissue sites in which patients after LT had severe amyloid deposition, which suggests that WT TTR tends to form amyloid in those tissue sites. Finally, although the truncation of TTR in amyloid deposits did not depend on undergoing LT, we elucidated the truncation of TTR occurred predominantly in patients from non-endemic areas of Japan, where FAP amyloidogenic TTR V30M patients are late onset and low penetrance, compared with patients from an endemic area of Japan.

CONCLUSIONS

FAP may shift to systemic WT TTR amyloid formation after LT, which seems to be similar to the process in SSA. The truncation of TTR in amyloid deposits may depend on some genetic or environmental factors other than undergoing LT.

Familial amyloid polyneuropathy

Familial amyloid polyneuropathy (FAP; also known as familiar amyloidosis and hereditary amyloidosis) is an autosomal dominant inherited disease due to mutations of the transthyretin (TTR) gene coding for the corresponding protein, consisting of 127 amino acids. The gene is located on chromosome 18q. More than 100 different mutations are known. Other mutant precursor proteins produced in the liver, such as apolipoprotein I and II, lysozyme and fibrinogen Aα, may be of etiological importance as well. Amyloidogenic mutations of the TTR gene lead to decreased stability of the corresponding protein and subsequently to extracellular deposition of amyloid in several tissues (peripheral and autonomic nerves, walls of the gastrointestinal tract, heart, etc.). The Val30Met mutation is the most prevalent cause of FAP worldwide. There are endemic regions in Portugal, Sweden and Japan. The onset of symptoms is usually between 25 and 35 years of age, but late-onset families are also known. The most common clinical symptoms are polyneuropathy of the lower limbs, rhythmological disturbances and diarrhea/obstipation. TTR amyloid is predominantly produced in the liver; only as few as 5% are synthesized in the retina and choroid plexus. Therefore, liver transplantation has become widely accepted as the ultimate curative treatment of this disease in order to prevent the ultimately fatal outcome and ameliorate disabling symptoms. Because of shortage of donor grafts, livers of FAP patients are used for domino liver transplantation. Last year, a new therapeutic option was approved by the European Medical Authority (EMA) for therapy of early-stage FAP. The first results of a multicenter-controlled trial have been published and show a benefit in patients with an early stage of disease regarding neurological symptoms as well as modified BMI. There are several other pharmacologic approaches that have been reported in the last years which may lead to stabilization of the TTR tetramer. Therefore, this might be the beginning of new therapeutic options with pharmacological therapies in patients with FAP.

Liver transplantation and transthyretin amyloidosis

Liver transplantation as a specific treatment of transthyretin amyloidosis was first performed in 1990. The rationale for this treatment was that removal of the source (liver) of the amyloid precursor protein (mutated transthyretin) would stop progression of the disease. Indeed, after orthotopic liver transplantation (OLT), mutant transthyretin (TTR) is rapidly cleared from circulation. In the last 20 years, >2000 familial amyloidotic polyneuropathy (FAP) patients have received liver transplants. For these patients, prospective monitoring has shown prolongation of life compared with FAP patients who have not undergone liver transplantation. The most favorable results have been for FAP patients with the Val30Met TTR mutation. Less favorable results have been seen for patients with other TTR mutations where progression of amyloid tissue deposition has been documented as the result of amyloid fibril formation from normal (wild-type) TTR. Although it is obvious that OLT has benefited many FAP patients, there remains a need for further therapies.

Vitreous surgery impact in glaucoma development in liver transplanted familial amyloidosis ATTR V30M Portuguese patients

PURPOSE

Familial amyloidosis with polyneuropathy (FAP) sometimes courses with vitreous amyloid. The aim of this study was to evaluate the incidence of glaucoma after vitrectomy in FAP patients.

METHODS

A total of 79 eyes of 42 liver transplanted FAP patients and 16 eyes of 16 non-FAP patients with rhegmatogenous retina detachment were collected. The patients were divided in to three groups: Group I - FAP patients with vitreous opacities submitted to vitrectomy, Group II - FAP patients without vitreous opacities and not submitted to vitrectomy and, Group III - non-FAP patients with rhegmatogenous retinal detachment submitted to vitrectomy. The Group I was subdivided into: Ia - "complete" vitrectomy; Ib - "incomplete" vitrectomy. The onset of glaucoma was considered when the intraocular pressure level was higher than 21 mmHg, with concomitant visual field abnormalities and optic nerve cupping.

RESULTS

Post vitrectomy glaucoma was more frequent in Group I (56.1%) than in Group III (12.5%) and in Group II (10.5%). We observed a higher incidence of glaucoma in the Ia than in the Ib subgroup (86.4 vs. 21.1%) and earlier appearance in subgroup Ia (7.9 ± 3.6 vs. 39.5 ± 6.6 months).

CONCLUSION

Vitrectomy induced the development of glaucoma in FAP patients.

Pathological changes long after liver transplantation in a familial amyloidotic polyneuropathy patient

Liver transplantation (LT) reportedly prolongs the survival of patients with familial amyloidotic polyneuropathy (FAP), a fatal hereditary systemic amyloidosis caused by mutant transthyretin (TTR). However, what happens in systemic tissue sites long after LT is poorly understood. In the present study, we report pathological and biochemical findings for an FAP patient who underwent LT and died from refractory ventricular fibrillation more than 16&emsp14;years after FAP onset. Our autopsy study revealed that the distributions of amyloid deposits after LT were quite different from those in FAP amyloidogenic TTR V30M patients not having had LT and seemed to be similar to those observed in senile systemic amyloidosis (SSA), a sporadic systemic amyloidosis derived from wild-type (WT) TTR. Our biochemical examination also revealed that this patient's cardiac and tongue amyloid deposits derived mostly from WT TTR. We propose that FAP patients after LT may suffer from SSA-like WT TTR amyloidosis in systemic organs.

Electrophysiological features of familial amyloid polyneuropathy in endemic area

The process of deterioration of peripheral nerve function in familial amyloid polyneuropathy (FAP) with amyloidogenic transthyretin (ATTR) Val30Met has not been systematically evaluated hitherto. We performed nerve conduction studies in 69 patients with FAP with ATTR Val30Met from one of the endemic areas in Japan. Sensory conduction velocity (SCV), motor conduction velocity (MCV), the size of the compound muscle action potential (CMAP) and distal latency (DL) were measured in the ulnar and tibial nerves. SCV was evaluated using the orthodromic method with needle recording electrodes. These electrophysiological parameters were compared with clinical stage of FAP and duration of neuropathy. When subjects noted minimal neuropathic symptoms only in the feet, motor and sensory nerve function in both the hands and feet had already been disturbed. Sensory nerve action potential on the foot disappeared more rapidly than CMAP. CMAP on foot muscle rapidly decreased during the initial 2 years and completely disappeared within 10 years. The duration of illness and deterioration parameters (CMAP of the abductor digiti minimi muscle, MCV and SCV of the ulnar nerve and DL of both ulnar and tibial nerves) were linearly correlated. CMAP was the most sensitive and reliable parameter to evaluate motor nerve degeneration in FAP.

Liver transplantation for inherited metabolic disorders of the liver

PURPOSE OF REVIEW

Liver transplantation is curative, life saving or both for a range of inherited diseases affecting the liver. Indications, timing and outcome of transplantation for these diseases are the focus of this review.

RECENT FINDINGS

Liver transplant represents a mode of gene replacement therapy for several disorders, including Wilson disease, hemochromatosis, tyrosinemia, urea cycle defects and hypercholesterolemia in which the primary defect residing in the liver results in hepatic complications or severe extrahepatic disease. Liver transplant is also an important therapeutic modality in multisystemic genetic disorders with major hepatic disease such as glycogen storage disease types I, III and IV and porphyria. For familial amyloidosis and primary hyperoxaluria, liver replacement eliminates the source of the injurious products that results in extrahepatic disease. Innovations in medical and surgical management of these patients have led to improved outcomes providing an important benchmark for future gene therapy of these disorders.

SUMMARY

Recent developments have refined the indications for liver transplant in the treatment of inherited metabolic diseases. The full potential of liver transplant in these disorders can be harnessed by careful patient selection, optimizing timing and perioperative metabolic management of these patients.

Liver transplantation and combined liver-heart transplantation in patients with familial amyloid polyneuropathy: a single-center experience

Liver transplantation (LT) is the only curative option for patients with familial amyloid polyneuropathy (FAP) at present. Twenty patients with FAP underwent LT between May 1998 and June 2007. Transthyretin mutations included predominantly the Val30Met mutation but also 10 other mutations. Seven patients received a pacemaker prior to LT, and because of impairment of mechanical cardiac function, 4 combined heart-liver transplants were performed, 1 simultaneously and 3 sequentially. The first patient, who underwent simultaneous transplantation, died. Seven patients died after LT, with 5 dying within the first year after transplantation. The causes of death were cardiac complications (4 patients), infections (2 patients), and malnutrition (1 patient). One-year survival was 75.0%, and 5-year survival was 64.2%. Gly47Glu and Leu12Pro mutations showed an aggressive clinical manifestation: 2 patients with the Gly47Glu mutation, the youngest patients of all the non-Val30Met patients, suffered from severe cardiac symptoms leading to death despite LT. Two siblings with the Leu12Pro mutation, who presented only with grand mal seizures, died after LT because of sepsis. In conclusion, the clinical course in patients with FAP is very variable. Cardiac symptoms occurred predominantly in patients with non-Val30Met mutations and prompted combined heart-liver transplantation in 4 patients. Although early LT in Val30Met is indicated in order to halt the typical symptoms of polyneuropathy, additional complications occurring predominantly with other mutations may prevail and lead to life-threatening complications or a fatal outcome. Combined heart-liver transplantation should be considered in patients with restrictive cardiomyopathy.

Liver transplantation for familial amyloidotic polyneuropathy: impact on Swedish patients' survival

Liver transplantation (LTx) for familial amyloidotic polyneuropathy (FAP) is an accepted treatment for this fatal disease. However, the long-term outcome with respect to that of nontransplanted patients has not been fully elucidated. The aim of this study was to compare the long-term survival of Swedish LTx FAP patients with that of historical controls, especially with respect to the age at onset of the disease and gender. In order to evaluate the outcome of LTx as a treatment for FAP, survival was calculated from the onset of disease. One hundred forty-one FAP patients, 108 transplanted and 33 not transplanted, were included in the study. Significantly increased survival was noted for LTx patients in comparison with controls. The outcome was especially favorable for those with an early onset of the disease (age at onset < 50 years) in comparison with early-onset controls (P < 0.001). In contrast, no significant difference for late-onset cases (> or = 50 years) was found. Transplanted late-onset females had significantly improved survival in comparison with transplanted late-onset males (P = 0.02). We were unable to find significant differences in survival between patients with long (> or = 7 years) or short (<7 years) disease duration at transplantation. The survival of male patients with late-onset disease appeared not to improve with LTx. LTx is an efficacious treatment for improving the survival of early-onset FAP patients. Further studies are needed to analyze the cause of the poorer outcome for late-onset male patients.

[Amyloid centers in Europe: the EURAMY project]

The systemic amyloidoses comprise a large group of serious protein deposition diseases. Although rather rare, the disorders are spread all over the world. Increasing understanding of pathogenic mechanisms and recent hope for treatment options demand further research and development of diagnostic procedures. The European Union Framework 6 program EURAMY (http://www.EURAMY.org) is devoted to all aspects of research on systemic amyloidoses, from molecular aspects to treatment of patients.

Prevalence of germline mutations in the TTR gene in a consecutive series of surgical pathology specimens with ATTR amyloid

Transthyretin-derived amyloidosis (ATTR) amyloidosis is the third most prevalent amyloid type in surgical pathology and may occur as a hereditary disease with germline mutations in the TTR gene or as senile systemic amyloidosis (SSA) without mutations. Distinction between hereditary ATTR amyloidosis and SSA is of central importance, as the former necessitates genetic counseling and can be treated by liver transplantation. However, little is known about the prevalence of hereditary ATTR amyloidosis in surgical pathology specimens. We have examined the distribution of hereditary ATTR amyloidosis and SSA in a consecutive series of surgical pathology specimens with histologically and immunohistochemically confirmed ATTR amyloid. Thirty-three consecutive patients were retrieved from the Amyloid Registry of the Charité University Hospital. Genomic DNA was extracted from formalin-fixed and paraffin-embedded tissue or patient blood and examined by DNA sequencing. ATTR amyloid was found in the gastrointestinal tract, endomyocardium, peripheral nerve, carpal tunnel ligament, synovia, breast, and testicle. Amyloid fibrils were present as interstitial and vascular deposits, as evidenced by Congo red staining. TTR gene mutations were detected in 12 of 30 patients, with p.Val30Met being the most prevalent (5 patients). Furthermore, 2 novel mutations (p.Asp39Val and p.Glu54Asp) were found. In patients carrying a mutation, ATTR amyloid was found in the gastrointestinal tract, myocardium, nerve, and testicles. To conclude, the hereditary form of ATTR amyloid seems to be more common in elderly patients than previously thought. It is, therefore, important to genetically test every patient when diagnosing ATTR amyloidosis.

Quality of life in patients with familial amyloidotic polyneuropathy long-term after liver transplantation

Liver transplantation aims to halt the progression of the disease in patients with familial amyloidotic polyneuropathy (FAP) caused by hereditary transthyretin-related (ATTR) amyloidosis. Insight in health-related quality of life of these transplanted FAP-patients can be of help to optimize health care delivery. The aim of this cross-sectional study was to assess the health-related quality of life of patients with FAP long-term after transplantation. Nine patients with a post-transplant follow-up of 4 years or more were included in the study. During the annual checks, health-related quality of life was measured with the Short Form-36 (SF-36). Data were compared with non-FAP transplanted patients with the same duration of follow-up and with the normal Dutch population. Pre-transplant, all patients had signs of mild to moderate peripheral polyneuropathy. The results showed that in patients with FAP health-related quality of life was stable in the first 4 years after transplantation. The domain of physical well-being at 4 years after transplantation was significantly lower compared to non-FAP transplanted patients and control Dutch population. The domain of emotional well-being was comparable with non-FAP controls. However, on most health areas patients with FAP scored lower than the non-FAP transplanted patients and the Dutch controls. After four years, the three patients with FAP with longest follow-up (9-12 years) deteriorated in all health domains, except in self-perceived mental health. This study, including only a small number of patients with FAP, shows a relatively low health-related quality of life after liver transplantation, which may deteriorate further with longer follow-up.

Amyloid fibril composition is related to the phenotype of hereditary transthyretin V30M amyloidosis

Swedish familial systemic amyloidosis with polyneuropathy (FAP) depends on a mutation leading to a methionine-for-valine substitution in transthyretin. The disease appears with different clinical manifestations, including age of onset and involvement of the heart. Liver transplantation is currently the only curative treatment, but progressive cardiomyopathy may occur post-transplant. Two amyloid deposition patterns have previously been described in the heart. In one, the amyloid consists partially of transthyretin fragments and is weakly stainable by Congo red, while in the other, only full-length molecules are found and the fibrils have a strong affinity for Congo red. The present study aimed to see whether these morphological and biochemical variations have clinical implications. Subcutaneous adipose tissue biopsies were taken from 33 patients with Val30Met FAP and examined by microscopy, electrophoresis and western blot. Clinical data included age, sex, duration of disease and echocardiographic determination of the interventricular septum (IVS) thickness. It was found that fibrils composed of only full-length transthyretin were associated with early age of onset (44.8 +/- 12.9 years), no clinical cardiac involvement and a strong affinity for Congo red. In contrast, presence of transthyretin fragments in the amyloid was associated with late age of onset (67.3 +/- 7.0 years), signs of cardiac involvement and weak Congo red staining. For each individual, the same molecular type of amyloid was found in different organs. This is the first report showing that variations in clinical appearance of familial ATTR amyloidosis are associated with specific structural differences in the amyloid fibrils, and therefore may have a molecular cause. The molecular type of amyloid can be determined from a subcutaneous fat tissue biopsy.

Ten-year follow-up of peripheral nerve function in patients with familial amyloid polyneuropathy after liver transplantation

BACKGROUND

The electrophysiological long-term effects of liver transplantation on peripheral nerve function in patients with familial amyloid polyneuropathy (FAP) have not been evaluated.

METHODS

Eight FAP patients with a proven ATTRVal30Met gene were observed for 10 years after liver transplantation. We performed repeated measurement of maximal motor nerve conduction velocity (MCV), distal latency, size of compound muscle action potential (CMAP) and maximal sensory nerve conduction velocity (SCV) in both the ulnar and tibial nerves. We also recorded the coefficients of variance in the R-R interval on the electrocardiogram (CV(R-R)).

RESULTS

Some autonomic symptoms subsided but motor and sensory symptoms 10 years after transplantation were either slightly improved or almost the same as before surgery in 7 of 8 patients. These 7 have returned to their previous social lives including their jobs. The MCV of the tibial nerve slightly improved, and other parameters of motor and sensory nerve function and CV(R-R) did not show any deterioration during the 10-year observation period.

CONCLUSIONS

Liver transplantation can halt the progression of peripheral neuropathy in FAP patients.

Evaluation of myocardial changes in familial amyloid polyneuropathy after liver transplantation

OBJECTIVE

The progression of cardiac amyloidosis is a prognostic factor after liver transplantation (LT) in familial amyloid polyneuropathy (FAP). The aim of this study was to assess myocardial changes in FAP amyloidgenic transthyretin (ATTR) Val30Met after LT.

PATIENTS AND METHODS

Twelve Japanese FAP ATTR Val30Met patients who underwent LT and were followed for more than 2 years, were examined with serial echocardiography after LT. Serum BNP levels were measured in 9 patients.

RESULTS

A significant increase in mean left atrial diameter and interventricular septal thickness was observed after LT. The increase in left atrial diameter was correlated with the presence of granular sparkling echo (GSE) at preoperative examination. Serum brain natriuretic peptide (BNP) levels in patients with left atrial diameter dilation (152.0+/-157.6 pg/mL) were higher than in those without left atrial diameter dilation (32.0+/-30.0 pg/mL).

CONCLUSION

LAD and IVS were significantly increased after LT compared with preoperative examinations in Japanese FAP ATTR Val30Met patients. BNP is an important biochemical indicator of myocardiac dysfunction in FAP patients. GSE is a useful echocardiographic marker to predict cardiac amyloidosis after LT.

Liver transplantation for familial amyloidotic polyneuropathy (FAP): a single-center experience over 16 years

Orthotopic liver transplantation (LTx) is currently the only available treatment that has been proven to halt the progress of familial amyloidotic polyneuropathy (FAP). The aim of this study was to assess mortality and symptomatic response to LTx for FAP. All 86 FAP patients transplanted at our hospital between April 1990 and November 2005 were included in the study. Five patients underwent retransplantation. The 1-, 3- and 5-year patient survival rates in patients transplanted during 1996-2005 were 94.6%, 92.3% and 92.3%, respectively, a significant difference from the rates of 76.7%, 66.7% and 66.7%, respectively, during 1990-1995 (p = 0.0003). Multivariate analysis revealed that the age at the time of LTx (>or=40 years), duration of the disease (>or=7 years) and modified body mass index (mBMI) (<600) were independent prognostic factors for patient survival. A halt in the progress of symptoms was noted in most patients, but only a minority experienced an improvement after LTx. To optimize the posttransplant prognosis, LTx should be performed in the early stages of the disease, and close post-LTx monitoring of heart function by echocardiography and of heart arrhythmia by Holter ECG is mandatory.

New insights into systemic amyloidosis: the importance of diagnosis of specific type

PURPOSE OF REVIEW

This review aims to summarize recent developments in the area of systemic amyloidoses with emphasis on pathologic diagnosis.

RECENT FINDINGS

In recent years, management of amyloidosis has shifted from a purely supportive approach to quite diverse, radical and aggressive treatments. The central issue is the understanding that treatment of systemic amyloidoses depends on the molecular type of the amyloid protein. In the United States and the Western world, AL-amyloidosis is the most prevalent type of systemic amyloidosis, but hereditary amyloidoses are being diagnosed with increasing frequency; genetics also plays a role in a subset of familial AA amyloidoses. The biggest challenge is in the diagnosis of AL-type with confidence and in differentiation of AL and hereditary amyloidoses. While careful clinico-pathologic correlation is recommended for all patients with amyloidosis, it is, in itself, not a substitute for amyloid typing.

SUMMARY

The diagnosis of the amyloid type ultimately depends on the examination of the amyloid protein within the deposits. The role of immunohistochemistry - the current standard of care in amyloid typing - is evolving with emergence of alternative biochemical methods. Amyloid, being essentially a protein disorder, presents an attractive venue for the application of proteomics methodologies, despite their inherent complexities.

Transthyretin-derived amyloid deposition on the gastric mucosa in domino recipients of familial amyloid polyneuropathy liver

Familial amyloid polyneuropathy (FAP) is a form of hereditary generalized amyloidosis. Liver tissue explanted from FAP patients has normal structure and function, except for the production of amyloidogenic variant transthyretin (TTR), and domino liver transplantation (DLT) using grafts from FAP patients was first performed in 1995. FAP symptoms usually develop in genetically determined individuals after the age of 20, but it is difficult to estimate when FAP symptoms will appear in domino recipients. Concerning this problem, histological findings showing amyloid deposition have recently been obtained in a few domino recipients of FAP livers. This study investigated the presence of de novo amyloid deposition in the gastroduodenal mucosa of domino recipients transplanted at our institution. Biopsy of gastroduodenal mucosa was carried out in 5 recipients of FAP livers and TTR-derived amyloid deposits were detected in 2 patients, both of whom had undergone DLT 47 months previously. In FAP liver recipients, de novo systemic amyloid deposition may begin much sooner than previously supposed. Therefore, careful follow-up of domino recipients of FAP livers is required.

Amyloidosis-associated kidney disease

The amyloidoses are a group of disorders in which soluble proteins aggregate and deposit extracellularly in tissues as insoluble fibrils, causing progressive organ dysfunction. The kidney is one of the most frequent sites of amyloid deposition in AL, AA, and several of the hereditary amyloidoses. Amyloid fibril formation begins with the misfolding of an amyloidogenic precursor protein. The misfolded variants self-aggregate in a highly ordered manner, generating protofilaments that interact to form fibrils. The fibrils have a characteristic appearance by electron microscopy and generate birefringence under polarized light when stained with Congo red dye. Advances in elucidating the mechanisms of amyloid fibril formation, tissue deposition, and tissue injury have led to new and more aggressive treatment approaches for these disorders. This article reviews the pathogenesis, diagnosis, clinical manifestations, and treatment of the amyloidoses, focusing heavily on the renal aspects of each of these areas.

Iatrogenic amyloid neuropathy in a Japanese patient after sequential liver transplantation

A 57-year-old woman in Japan, the first recipient of part of a liver from a 58-year-old man with familial amyloidotic polyneuropathy (FAP) amyloidogenic transthyretin Val30Met who had had sensorimotor polyneuropathy in the lower limbs for 3 years, started to develop sensory neuropathy 7 years after transplantation. Before the July 1998 sequential transplantation, she had been in a hepatic coma at the terminal stage of primary biliary cirrhosis and waiting for deceased donor liver transplantation. In September 2004, biopsy samples of her duodenum first showed amyloid deposition. Although biopsy materials in 2005 and 2006 showed no changes in amyloid deposition, decreased temperature sensation and pain in fingertips and toes were detected at a neurologic examination in March 2006. Thus, clinical symptoms of FAP appeared about 2 years after amyloid deposition started. Nerve conduction velocity studies revealed mild to moderate axonal sensory polyneuropathy without demyelination. Our findings confirmed iatrogenic sensory neuropathy induced by amyloid deposition 7 years after sequential liver transplantation.