David Adams

Domino liver transplants for metabolic disorders: experience with familial amyloidotic polyneuropathy

Abstract Background: Shortage of liver donors means that new methods of liver procurement must be explored. In domino transplantation, organs explanted during transplantation in one patient are transplanted into a second patient. Domino procedures can be performed with livers from patients having transplantion for hepatic metabolic disorders that cause systemic disease without affecting other liver functions. Familial amyloidotic polyneuropathy (FAP) type I is one of these. Study Design: We reviewed the Paul Brousse experience with a domino liver transplant program for FAP, hoping to extend the approach to other metabolic disorders. Results: Livers from 10 patients transplanted for FAP type 1 were used for domino transplants to patients with unresectable primary or metastatic liver cancers. There was no perioperative mortality. Neuropathy or cardiomyopathy did not increase the morbidity of the domino liver explant and transplant procedures. Morbidity for the domino recipients did not appear to be increased. Variant transthyretin was detected in the serum in FAP liver recipients, with no immediate clinical consequences. Conclusions: The domino approach is feasible and requires careful planning of the surgical procedures for liver explantation, particularly for the nature and site of vascular anastomoses. Domino transplantation of metabolically dysfunctional livers creates new categories of potential donors and potential recipients. It raises new ethical, technical, and societal issues. The domino approach could be used in several genetic or biochemical disorders now treated by liver transplantation. It has the potential to increase the number of liver grafts available for transplantation.

Hereditary systemic amyloidosis due to Asp76Asn variant β2-microglobulin.

We describe a kindred with slowly progressive gastrointestinal symptoms and autonomic neuropathy caused by autosomal dominant, hereditary systemic amyloidosis. The amyloid consists of Asp76Asn variant β(2)-microglobulin. Unlike patients with dialysis-related amyloidosis caused by sustained high plasma concentrations of wild-type β(2)-microglobulin, the affected members of this kindred had normal renal function and normal circulating β(2)-microglobulin values. The Asp76Asn β(2)-microglobulin variant was thermodynamically unstable and remarkably fibrillogenic in vitro under physiological conditions. Previous studies of β(2)-microglobulin aggregation have not shown such amyloidogenicity for single-residue substitutions. Comprehensive biophysical characterization of the β(2)-microglobulin variant, including its 1.40-Å, three-dimensional structure, should allow further elucidation of fibrillogenesis and protein misfolding.

Evolving landscape in the management of transthyretin amyloidosis.

Transthyretin (TTR) amyloidosis (ATTR amyloidosis) is a multisystemic, multigenotypic disease resulting from deposition of insoluble ATTR amyloid fibrils in various organs and tissues. Although considered rare, the prevalence of this serious disease is likely underestimated because symptoms can be non-specific and diagnosis largely relies on amyloid detection in tissue biopsies. Treatment is guided by which tissues/organs are involved, although therapeutic options are limited for patients with late-stage disease. Indeed, enthusiasm for liver transplantation for familial ATTR amyloidosis with polyneuropathy was dampened by poor outcomes among patients with significant neurological deficits or cardiac involvement. Hence, there remains an unmet medical need for new therapies. The TTR stabilizers tafamidis and diflunisal slow disease progression in some patients with ATTR amyloidosis with polyneuropathy, and the postulated synergistic effect of doxycycline and tauroursodeoxycholic acid on dissolution of amyloid is under investigation. Another therapeutic approach is to reduce production of the amyloidogenic protein, TTR. Plasma TTR concentration can be significantly reduced with ISIS-TTRRx, an investigational antisense oligonucleotide-based drug, or with patisiran and revusiran, which are investigational RNA interference-based therapeutics that target the liver. The evolving treatment landscape for ATTR amyloidosis brings hope for further improvements in clinical outcomes for patients with this debilitating disease.

First European consensus for diagnosis, management, and treatment of transthyretin familial amyloid polyneuropathy

Purpose of review Early and accurate diagnosis of transthyretin familial amyloid polyneuropathy (TTR-FAP) represents one of the major challenges faced by physicians when caring for patients with idiopathic progressive neuropathy. There is little consensus in diagnostic and management approaches across Europe. Recent findings The low prevalence of TTR-FAP across Europe and the high variation in both genotype and phenotypic expression of the disease means that recognizing symptoms can be difficult outside of a specialized diagnostic environment. The resulting delay in diagnosis and the possibility of misdiagnosis can misguide clinical decision-making and negatively impact subsequent treatment approaches and outcomes. Summary This review summarizes the findings from two meetings of the European Network for TTR-FAP (ATTReuNET). This is an emerging group comprising representatives from 10 European countries with expertise in the diagnosis and management of TTR-FAP, including nine National Reference Centres. The current review presents management strategies and a consensus on the gold standard for diagnosis of TTR-FAP as well as a structured approach to ongoing multidisciplinary care for the patient. Greater communication, not just between members of an individual patients treatment team, but also between regional and national centres of expertise, is the key to the effective management of TTR-FAP.

Rapid progression of familial amyloidotic polyneuropathy: a multinational natural history study.

Objectives: To assess the association between severity of neuropathy and disease stage, and estimate the rate of neuropathy progression in a retrospective cross-sectional analysis of a multinational population of patients with familial amyloidotic polyneuropathy (FAP). Methods: We characterize neuropathy severity and rate of progression in available patients with FAP in France, the United States, Portugal, and Italy. Neuropathy Impairment Scores (NIS), time from symptom onset to NIS measurement, polyneuropathy disability (PND) scores, FAP disease stage, and manual grip strength data were collected. We estimated neuropathy progression using Loess Fit and Gompertz Fit models. Results: For the 283 patients studied (mean age, 56.4 years), intercountry genotypic variation in the transthyretin (TTR) mutation was observed, with the majority of patients in Portugal (92%) having early-onset Val30Met-FAP. There was also marked intercountry variation in PND score, FAP stage, and TTR stabilizer use. NIS was associated with PND score (NIS 10 and 99 for scores I and IV, respectively; p < 0.0001) and FAP stage (NIS 14 and 99 for stages 1 and 3, respectively; p < 0.0001). In addition, there was an association between NIS and TTR genotype. The estimated rate of NIS progression for a population with a median NIS of 32 was 14.3 points/year; the corresponding estimated rate for the modified NIS+7 is 17.8 points/year. Conclusions: In a multinational population of patients with FAP, rapid neuropathic progression is observed and the severity of neuropathy is associated with functional scales of locomotion.

Immunological Hallmarks of JC Virus Replication in Multiple Sclerosis Patients on Long-Term Natalizumab Therapy

ABSTRACT Progressive multifocal leukoencephalopathy (PML) is the main adverse effect of natalizumab. Detectable JC virus-specific effector memory T-cell (TEM) responses may indicate ongoing JCV replication. We detected JCV-specific TEM responses in blood of patients with multiple sclerosis (MS) treated with natalizumab, including 2 patients with PML. The frequency of detection of these responses increased with the time on natalizumab. Thus, a subset of MS patients exhibit immunological hallmarks of JCV replication during prolonged natalizumab therapy.

Hereditary and inflammatory neuropathies: a review of reported associations, mimics and misdiagnoses

Distinguishing between hereditary and inflammatory neuropathy is usually straightforward on clinical grounds with the help of a family history. There are nevertheless cases where the distinction is less clear. The advent of molecular genetics has in the past several years aided confirmatory diagnosis for an increasing proportion of patients with genetic neuropathy. Various reports have described associations of Charcot-Marie-Tooth disease with a suspected or confirmed inflammatory neuropathy occasionally responding to immunotherapy. Possible predisposition to an inflammatory component was suggested in a subset of patients. Such reports have, however, been relatively few in number, suggesting the rarity of such associations and of such a predisposition if it exists. There have been a number of publications detailing clinical presentations suggestive of inflammatory neuropathy in patients with a known or later proven genetic aetiology, and subsequently felt to be part of the phenotype rather than representing an association. A number of genetically mediated multisystemic diseases with neuropathy have otherwise been reported as mimicking chronic inflammatory demyelinating polyneuropathy (CIDP). The most common example is that of familial amyloid polyneuropathy, of particular concern for the clinician when misdiagnosed as CIDP, in view of the therapeutic implications. We review the literature on reported associations, mimics and misdiagnoses of hereditary and inflammatory neuropathy and attempt to determine a practical approach to the problem in clinical practice using clinical features, electrophysiology, histopathology and targeted early genetic testing. The issue of attempting immunomodulatory therapy is discussed in view of the published literature.

Assessing mNIS+7Ionis and International Neurologists' Proficiency in an FAP Trial.

Polyneuropathy signs (Neuropathy Impairment Score, NIS), neurophysiologic tests (m+7Ionis), disability, and health scores were assessed in baseline evaluations of 100 patients entered into an oligonucleotide familial amyloidotic polyneuropathy (FAP) trial.

Assessing mNIS+7Ionis and international neurologists' proficiency in a familial amyloidotic polyneuropathy trial

Polyneuropathy signs (Neuropathy Impairment Score, NIS), neurophysiologic tests (m+7Ionis), disability, and health scores were assessed in baseline evaluations of 100 patients entered into an oligonucleotide familial amyloidotic polyneuropathy (FAP) trial.

Circadian rhythm of blood pressure reflects the severity of cardiac impairment in familial amyloid polyneuropathy

BACKGROUND Cardiac amyloidosis due to familial amyloid polyneuropathy (FAP) includes restrictive cardiomyopathy, thickened cardiac walls, conduction disorders and cardiac denervation. Impaired blood pressure variability has been documented in FAP related to the Val30Met mutation. AIMS To document blood pressure variability in FAP patients with various mutation types and its relationship to the severity of cardiac involvement. METHODS Blood pressure variability was analysed in 49 consecutive FAP patients and was compared with a matched control population. Cardiac evaluation included echocardiography, right heart catheterization, electrophysiological study, Holter electrocardiogram and metaiodobenzylguanidine (MIBG) scintigraphy. RESULTS A non-dipping pattern was found in 80% of FAP patients and in 35% of control patients (P<0.0001); this was due to a significantly lower diurnal blood pressure in FAP patients (FAP group, 113 ± 21 mmHg; control group, 124 ± 8 mmHg; P<0.0001), whereas nocturnal blood pressures were similar. Among FAP patients, a non-dipping pattern was significantly associated with haemodynamic involvement, cardiac thickening or conduction disorders. These associations did not depend on the average blood pressure levels. Impaired blood pressure variability was more frequent and more pronounced in patients with multiple criteria for severe cardiac amyloidosis. CONCLUSION Low blood pressure variability is common in cardiac amyloidosis due to FAP. A non-dipping pattern was more frequently observed in FAP patients with haemodynamic impairment, cardiac thickening or conduction disorders. It is suggested that impairment of circadian rhythm of blood pressure reflects the severity of cardiac amyloidosis due to FAP.