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JAMA Jul 2020Many patients with systemic amyloidosis are underdiagnosed. Overall, 25% of patients with immunoglobulin light chain (AL) amyloidosis die within 6 months of diagnosis...
IMPORTANCE
Many patients with systemic amyloidosis are underdiagnosed. Overall, 25% of patients with immunoglobulin light chain (AL) amyloidosis die within 6 months of diagnosis and 25% of patients with amyloid transthyretin (ATTR) amyloidosis die within 24 months of diagnosis. Effective therapy exists but is ineffective if end-organ damage is severe.
OBJECTIVE
To provide evidence-based recommendations that could allow clinicians to diagnose this rare set of diseases earlier and enable accurate staging and counseling about prognosis.
EVIDENCE REVIEW
A comprehensive literature search was conducted by a reference librarian with publication dates from January 1, 2000, to December 31, 2019. Key search terms included amyloid, amyloidosis, nephrotic syndrome, heart failure preserved ejection fraction, and peripheral neuropathy. Exclusion criteria included case reports, non-English-language text, and case series of fewer than 10 patients. The authors independently selected and appraised relevant literature.
FINDINGS
There was a total of 1769 studies in the final data set. Eighty-one articles were included in this review, of which 12 were randomized clinical trials of therapy that included 3074 patients, 9 were case series, and 3 were cohort studies. The incidence of AL amyloidosis is approximately 12 cases per million persons per year and there is an estimated prevalence of 30 000 to 45 000 cases in the US and European Union. The incidence of variant ATTR amyloidosis is estimated to be 0.3 cases per year per million persons with a prevalence estimate of 5.2 cases per million persons. Wild-type ATTR is estimated to have a prevalence of 155 to 191 cases per million persons. Amyloidosis should be considered in the differential diagnosis of adult nondiabetic nephrotic syndrome; heart failure with preserved ejection fraction, particularly if restrictive features are present; unexplained hepatomegaly without imaging abnormalities; peripheral neuropathy with distal sensory symptoms, such as numbness, paresthesia, and dysesthesias (although the autonomic manifestations occasionally may be the presenting feature); and monoclonal gammopathy of undetermined significance with atypical clinical features. Staging can be performed using blood testing only. Therapeutic decision-making for AL amyloidosis involves choosing between high-dose chemotherapy and stem cell transplant or bortezomib-based chemotherapy. There are 3 therapies approved by the US Food and Drug Administration for managing ATTR amyloidosis, depending on clinical phenotype.
CONCLUSIONS AND RELEVANCE
All forms of amyloidosis are underdiagnosed. All forms now have approved therapies that have been demonstrated to improve either survival or disability and quality of life. The diagnosis should be considered in patients that have a multisystem disorder involving the heart, kidney, liver, or nervous system.
Topics: Algorithms; Benzoxazoles; Dexamethasone; Diagnosis, Differential; Gene Silencing; Heart Failure; Humans; Immunoglobulin Light-chain Amyloidosis; Liver Transplantation; Melphalan; Prognosis; Proteinuria; Stem Cell Transplantation
PubMed: 32633805
DOI: 10.1001/jama.2020.5493 -
European Journal of Heart Failure Sep 2022Systematic evidence on the prevalence and clinical outcome of transthyretin amyloidosis (ATTR) is missing. We explored: (i) the prevalence of cardiac amyloidosis in... (Meta-Analysis)
Meta-Analysis
AIM
Systematic evidence on the prevalence and clinical outcome of transthyretin amyloidosis (ATTR) is missing. We explored: (i) the prevalence of cardiac amyloidosis in various patient subgroups, (ii) survival estimates for ATTR subtypes, and (iii) the effects of novel therapeutics on the natural course of disease.
METHODS AND RESULTS
A systematic review of literature published in MEDLINE before 31 December 2021 was performed for the prevalence of cardiac amyloidosis and all-cause mortality of ATTR patients. Extracted data included sample size, age, sex, and all-cause mortality at 1, 2, and 5 years. Subgroup analyses were performed for ATTR subtype, that is, wild-type ATTR (wtATTR) versus hereditary ATTR (hATTR), hATTR genotypes, and treatment subgroups. We identified a total of 62 studies (n = 277 882 individuals) reporting the prevalence of cardiac amyloidosis, which was high among patients with a hypertrophic cardiomyopathy phenotype, heart failure with preserved ejection fraction, and the elderly with aortic stenosis. Data on ATTR mortality were extracted from 95 studies (n = 18 238 ATTR patients). Patients with wtATTR were older (p = 7 × 10 ) and more frequently male (p = 5 × 10 ) versus hATTR. The 2-year survival of ATTR was 73.3% (95% confidence interval [CI] 70.9-75.7); for non-subtyped ATTR 70.4% (95% CI 66.9-73.9), for wtATTR 76.0% (95% CI 73.0-78.9]) and for hATTR 77.2% (95% CI 74.0-80.4); in meta-regression analysis, wtATTR was associated with higher survival after adjusting for confounders. There was an interaction between survival and hATTR genotypes (p = 10 , Val30Met having the lowest and Val122Ile/Thr60Ala the highest mortality). ATTR 2-year survival was higher on tafamidis/patisiran compared to natural disease course (79.9%, 95% CI 74.4-85.3 vs. 72.4%, 95% CI 69.8-74.9, p < 0.05).
CONCLUSIONS
We report the prevalence of ATTR in various population subgroups and provide survival estimates for the natural course of disease and the effects of novel therapeutics. Important gaps in worldwide epidemiology research in ATTR were identified.
Topics: Amyloid Neuropathies, Familial; Cardiomyopathies; Heart Failure; Humans; Male; Prevalence
PubMed: 35730461
DOI: 10.1002/ejhf.2589 -
Acta Neurologica Scandinavica Feb 2019Hereditary transthyretin(TTR)-related amyloidosis (ATTRm amyloidosis) is an endemic/non-endemic, autosomal-dominant, early- and late-onset, rare, progressive disorder,...
Hereditary transthyretin(TTR)-related amyloidosis (ATTRm amyloidosis) is an endemic/non-endemic, autosomal-dominant, early- and late-onset, rare, progressive disorder, predominantly manifesting as length-dependent, small fiber dominant, axonal polyneuropathy and frequently associated with cardiac disorders and other multisystem diseases. ATTRm amyloidosis is due to variants in the TTR gene, with the substitution Val30Met as the most frequent mutation. TTR mutations lead to destabilization and dissociation of TTR tetramers into variant TTR monomers, and formation of amyloid fibrils, which are consecutively deposited extracellularly in various tissues, such as nerves, heart, brain, eyes, intestines, kidneys, or the skin. Neuropathy may not only include large nerve fibers but also small fibers, and not only sensory and motor fibers but also autonomic fibers. Types of TTR variants, age at onset, penetrance, and clinical presentation vary between geographical areas. Suggestive of a ATTRm amyloidosis are a sensorimotor polyneuropathy, positive family history, autonomic dysfunction, cardiomyopathy, carpal tunnel syndrome, unexplained weight loss, and resistance to immunotherapy. If only sensory A-delta or C fibers are affected, small fiber neuropathy ensues. Diagnostic tests for small fiber neuropathy include determination of intraepidermal nerve fiber density, laser-evoked potentials, heat- and cold-detection thresholds, and measurement of the electrochemical skin conductance. Therapy currently relies on liver transplantation and TTR-stabilizers (tafamidis, diflunisal).
Topics: Amyloid Neuropathies, Familial; Humans; Mutation; Prealbumin
PubMed: 30295933
DOI: 10.1111/ane.13035 -
European Journal of Neurology Jul 2021The coexistence of peripheral neuropathy (PN) and restless legs syndrome (RLS) or Willis-Ekbom disease is relatively frequent, but its prevalence has shown a high... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND AND PURPOSE
The coexistence of peripheral neuropathy (PN) and restless legs syndrome (RLS) or Willis-Ekbom disease is relatively frequent, but its prevalence has shown a high variability across studies. In addition, several reports have shown data suggesting the presence of PN in patients with idiopathic RLS.
METHODS
A search was undertaken using the PubMed, Embase and Web of Science Databases, from 1966 to 6 December 2020, crossing the search term 'restless legs syndrome' with 'neuropathy', 'polyneuropathy' (PNP) and 'peripheral neuropathy', and the references of interest for this topic were identified; a meta-analysis was performed, according to PRISMA guidelines, and a calculation of pooled prevalences, where appropriate, was made using standard methods.
RESULTS
Restless legs syndrome has been reported in 5.2%-53.7% of patients with PN (average 21.5%; 95% confidence interval 18.6%-24.5%), and PN has been reported in 0%-87.5% of patients with RLS (average 41.8%; 95% confidence interval 39.9%-43.6%), both being significantly more frequent than in controls. The heterogeneity across studies could be due to differences in the diagnostic criteria used for both RLS and PN. RLS is a frequent clinical complaint in patients with PN of different aetiologies, mainly diabetic PN, uraemic PNP, familial amyloid PNP, Charcot-Marie-Tooth disease and chronic dysimmune inflammatory PNP. Recent neurophysiological findings suggest the presence of small sensory fibre loss in patients diagnosed with idiopathic RLS, but it remains to be determined whether RLS associated with small sensory fibre loss and idiopathic RLS are different clinical entities.
CONCLUSIONS
Future studies including clinical and neurophysiological assessment and skin biopsy involving a large series of patients with PN and RLS are needed for a better understanding of the association between these two entities.
Topics: Amyloid Neuropathies, Familial; Charcot-Marie-Tooth Disease; Diabetic Neuropathies; Humans; Polyneuropathies; Restless Legs Syndrome
PubMed: 33772991
DOI: 10.1111/ene.14840 -
ESC Heart Failure Jun 2022Wild-type transthyretin amyloid cardiomyopathy (ATTRwt CM) is a more common disease than previously thought. Awareness of ATTRwt CM and its diagnosis has been challenged... (Review)
Review
Wild-type transthyretin amyloid cardiomyopathy (ATTRwt CM) is a more common disease than previously thought. Awareness of ATTRwt CM and its diagnosis has been challenged by its unspecific and widely distributed clinical manifestations and traditionally invasive diagnostic tools. Recent advances in echocardiography and cardiac magnetic resonance (CMR), non-invasive diagnosis by bone scintigraphy, and the development of disease-modifying treatments have resulted in an increased interest, reflected in multiple publications especially during the last decade. To get an overview of the scientific knowledge and gaps related to patient entry, suspicion, diagnosis, and systematic screening of ATTRwt CM, we developed a framework to systematically map the available evidence of (i) when to suspect ATTRwt CM in a patient, (ii) how to diagnose the disease, and (iii) which at-risk populations to screen for ATTRwt CM. Articles published between 2010 and August 2021 containing part of or a full diagnostic pathway for ATTRwt CM were included. From these articles, data for patient entry, suspicion, diagnosis, and screening were extracted, as were key study design and results from the original studies referred to. A total of 50 articles met the inclusion criteria. Of these, five were position statements from academic societies, while one was a clinical guideline. Three articles discussed the importance of primary care providers in terms of patient entry, while the remaining articles had the cardiovascular setting as point of departure. The most frequently mentioned suspicion criteria were ventricular wall thickening (44/50), carpal tunnel syndrome (42/50), and late gadolinium enhancement on CMR (43/50). Diagnostic pathways varied slightly, but most included bone scintigraphy, exclusion of light-chain amyloidosis, and the possibility of doing a biopsy. Systematic screening was mentioned in 16 articles, 10 of which suggested specific at-risk populations for screening. The European Society of Cardiology recommends to screen patients with a wall thickness ≥12 mm and heart failure, aortic stenosis, or red flag symptoms, especially if they are >65 years. The underlying evidence was generally good for diagnosis, while significant gaps were identified for the relevance and mutual ranking of the different suspicion criteria and for systematic screening. Conclusively, patient entry was neglected in the reviewed literature. While multiple red flags were described, high-quality prospective studies designed to evaluate their suitability as suspicion criteria were lacking. An upcoming task lies in defining and evaluating at-risk populations for screening. All are steps needed to promote early detection and diagnosis of ATTRwt CM, a prerequisite for timely treatment.
Topics: Amyloid Neuropathies, Familial; Cardiomyopathies; Contrast Media; Gadolinium; Humans; Prealbumin; Prospective Studies
PubMed: 35343098
DOI: 10.1002/ehf2.13884 -
Revista Da Associacao Medica Brasileira... Jan 2021To review the literature and to report a clinical case with initial suspicion of pure neural leprosy and final diagnosis of amyloid neuropathy.
OBJECTIVE
To review the literature and to report a clinical case with initial suspicion of pure neural leprosy and final diagnosis of amyloid neuropathy.
METHODS
The study was conducted in two stages. In stage one, a systematic literature review was carried out, with searches performed in the PubMed, Medline, and Lilacs databases, as well as in the leprosy sectoral library of the Virtual Health Library, using the following descriptors: neuritic leprosy, pure neural leprosy, primary neural leprosy, pure neuritic leprosy, amyloid polyneuropathy, amyloid neuropathies, and amyloid polyneuropathy. The search was carried out on May 28, 2020. Clinical trials, cohort studies, cross-sectional studies, clinical cases, and case studies published in Portuguese, English or Spanish between 2010 and 2020 were included. Stage two reports a case with initial suspicion of pure neural leprosy. Laboratory tests, electroneuromyography, ultrasound, and biopsy of the sural nerve were requested.
RESULTS
Twenty-three scientific texts were included. No publications were found that contained both topics together. The challenging diagnosis of pure neural leprosy and the possibility of using auxiliary resources in diagnosis were the most emphasized themes in the studies. In the clinical case, the patient's electroneuromyography showed sensitive and motor polyneuropathy of the lower limbs, which was predominantly sensory and axonal, symmetrical, of moderate intensity, and the mixed type (axonal-demyelinating). Ultrasonography of the sural nerve revealed changes in the contour of the deep fibular nerves; biopsy of the sural nerve showed an accumulation of amorphous eosinophilic material in the nerve path, and Congo red stain showed apple-green birefringence of the deposit under polarized light. The final diagnosis was amyloid neuropathy.
CONCLUSIONS
The final clinical diagnosis was amyloid neuropathy. The diagnosis of pure neural leprosy in endemic areas in Brasil is still a challenge for the health system.
Topics: Amyloid Neuropathies; Brazil; Cross-Sectional Studies; Humans; Leprosy; Leprosy, Tuberculoid
PubMed: 34161469
DOI: 10.1590/1806-9282.67.01.20200422 -
International Journal of Molecular... Mar 2024Peripheral and autonomic neuropathy are common disease manifestations in systemic amyloidosis. The neurofilament light chain (NfL), a neuron-specific biomarker, is... (Review)
Review
Peripheral and autonomic neuropathy are common disease manifestations in systemic amyloidosis. The neurofilament light chain (NfL), a neuron-specific biomarker, is released into the blood and cerebrospinal fluid after neuronal damage. There is a need for an early and sensitive blood biomarker for polyneuropathy, and this systematic review provides an overview on the value of NfL in the early detection of neuropathy, central nervous system involvement, the monitoring of neuropathy progression, and treatment effects in systemic amyloidosis. A literature search in PubMed, Embase, and Web of Science was performed on 14 February 2024 for studies investigating NfL levels in patients with systemic amyloidosis and transthyretin gene-variant (v) carriers. Only studies containing original data were included. Included were thirteen full-text articles and five abstracts describing 1604 participants: 298 controls and 1306 v carriers or patients with or without polyneuropathy. Patients with polyneuropathy demonstrated higher NfL levels compared to healthy controls and asymptomatic carriers. Disease onset was marked by rising NfL levels. Following the initiation of transthyretin gene-silencer treatment, NfL levels decreased and remained stable over an extended period. NfL is not an outcome biomarker, but an early and sensitive disease-process biomarker for neuropathy in systemic amyloidosis. Therefore, NfL has the potential to be used for the early detection of neuropathy, monitoring treatment effects, and monitoring disease progression in patients with systemic amyloidosis.
Topics: Humans; Prealbumin; Intermediate Filaments; Immunoglobulin Light-chain Amyloidosis; Amyloidosis; Polyneuropathies; Biomarkers
PubMed: 38612579
DOI: 10.3390/ijms25073770 -
Heart Failure Reviews Jan 2021Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive, life-threatening disease characterized by deposition of insoluble amyloid fibrils in the myocardium,...
Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive, life-threatening disease characterized by deposition of insoluble amyloid fibrils in the myocardium, resulting in cardiac structural and functional abnormalities and ultimately heart failure. Disease frequency is reportedly lower in women than men, but sex-related differences have not been well established. We conducted a systematic literature review (SLR), based on PRISMA-P guidelines and registered with PROSPERO, to assess whether the epidemiology and clinical presentation of ATTR-CM differ between women and men. MEDLINE, Embase, and Cochrane databases and selected conference proceedings were searched (August 16, 2019) to identify observational and clinical studies reporting sex-specific data for patients with wild-type or hereditary ATTR-CM. Of 193 publications satisfying final eligibility criteria, 69 studies were included in our pooled analysis. Among the 4669 patients with ATTR-CM analyzed, 791 (17%) were women, including 174 (9%), 366 (29%), and 251 (18%) in studies of wild-type, hereditary, and undefined ATTR-CM, respectively. Data available on disease characteristics were limited and very heterogeneous, but trends suggested some cardiac structural/functional differences, i.e., lower interventricular septal and posterior wall thickness and left ventricular (LV) end diastolic diameter, and higher LV ejection fractions, in women versus men across ATTR-CM subtypes. Because LV wall thickness > 12 mm is generally the suggested threshold for ATTR-CM diagnosis in both sexes, smaller cardiac anatomy in women with the disease may lead to underdiagnosis. Additional research and studies are needed to elucidate potential disparities between sexes in ATTR-CM frequency, clinical characteristics, and underlying biological mechanisms. This study was registered within the International Prospective Register of Systematic Reviews (PROSPERO) database of the University of York (CRD42019146995).
Topics: Amyloid Neuropathies, Familial; Cardiomyopathies; Female; Humans; Male; Prealbumin
PubMed: 32794090
DOI: 10.1007/s10741-020-10010-8 -
BioMed Research International 2015This paper aims to review the morphological and functional characteristics of patients affected by familial amyloid polyneuropathy (FAP), with greater focus on type I... (Review)
Review
PURPOSE
This paper aims to review the morphological and functional characteristics of patients affected by familial amyloid polyneuropathy (FAP), with greater focus on type I and its progression after liver transplantation. We also analyse therapeutic options for the ophthalmic manifestations.
METHODS
The literature from 2002 through 2015 was reviewed, with a total of 45 articles studied, using the key terms related to amyloidosis and its therapeutic approaches. Information was collated, evaluated, critically assessed, and then summarised in its present form. PATHOPHYSIOLOGY AND TREATMENT: FAP results from mutation of the transthyretin gene, with Val30Met being the most frequent substitution. The symptoms are those typical of a sensorimotor autonomic neuropathy and can be halted with liver transplantation. Nowadays there are new medical therapies that delay the progression of the systemic neuropathy. However, there are still no options to avoid ocular disease.
CONCLUSION
The main ocular manifestations in patients with FAP type I are amyloid deposition in the vitreous, dry eye, and secondary glaucoma. Despite liver transplantation, eye synthesis of amyloid persists and is associated with progressive ocular manifestations, which require continued ophthalmologic follow-up. New therapeutic strategies are therefore needed, particularly to target the ocular synthesis of the abnormal protein.
Topics: Adult; Amyloid Neuropathies, Familial; Female; Humans; Iris; Male; Middle Aged
PubMed: 26558262
DOI: 10.1155/2015/282405 -
Journal of Nuclear Cardiology :... Feb 2020Recent progress in amyloid positron emission tomography (PET) has enabled the targeted imaging of cardiac amyloidosis with accuracy. We performed a systematic review and... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Recent progress in amyloid positron emission tomography (PET) has enabled the targeted imaging of cardiac amyloidosis with accuracy. We performed a systematic review and meta-analysis on the diagnostic performance of cardiac amyloidosis using amyloid PET.
METHODS
A systematic search was performed using key words: cardiac amyloidosis, amyloid, and PET. We estimated the pooled sensitivity, specificity, positive and negative likelihood ratio (LR), and diagnostic odds ratio (DOR). Furthermore, the semiquantitative parameters of PET were evaluated to diagnose cardiac amyloidosis and discern its type [systemic light chain amyloidosis (AL) vs transthyretin amyloidosis (ATTR)] using the pooled standardized mean difference (SMD).
RESULTS
In total, six eligible studies with a total of 98 subjects were included in this meta-analysis. The pooled sensitivity was 0.95, the specificity was 0.98, positive LR was 10.130, negative LR was 0.1, and DOR was 148.83. The semiquantitative parameters of amyloid PET showed significantly higher values for cardiac amyloidosis patients than those for controls (pooled SMD = 1.42; P < .001), and in AL than ATTR (pooled SMD = 0.96; P < .001).
CONCLUSION
Amyloid PET imaging can be a useful method for diagnosing cardiac amyloidosis. The semiquantitative parameters of amyloid PET can help diagnose cardiac amyloidosis and discern its type.
Topics: Amyloid; Amyloid Neuropathies, Familial; Heart Diseases; Humans; Positron-Emission Tomography; Sensitivity and Specificity
PubMed: 30022405
DOI: 10.1007/s12350-018-1365-x