Fibrilación auricular en amiloidosis por transtirretina / Atrial fibrillation in transthyretin amyloidosis

Resumen La amiloidosis cardiaca es una enfermedad que se caracteriza por el depósito de material amiloide en la matriz extracelular del miocardio. Las arritmias son parte del amplio espectro de la enfermedad, de las cuales la fibrilación auricular (FA) es la más frecuente de todas. Debido a la heterogeneidad de la amiloidosis cardiaca, su incidencia real es desconocida, con lo que se denota un subdiagnóstico y en muchos casos estando oculta bajo la presentación de una enfermedad cardiaca habitual, lo que conlleva a una progresión silente de la misma y peores desenlaces. Se describe el caso clínico de un paciente con FA refractaria a cardioversión eléctrica y terapia ablativa en el contexto de amiloidosis cardiaca por transtirretina (ATTR) inicialmente inadvertida y descubierta como hallazgo incidental. El propósito de este reporte es revisar la asociación entre FA y ATTR, su epidemiología, fisiopatología, manifestación clínica, diagnóstico y tratamiento con el fin de ofrecer al personal médico herramientas para un diagnóstico oportuno de una enfermedad poco reconocida.

Abstract Cardiac amyloidosis is a disease characterized by the deposition of amyloid material in the extracellular matrix of the myocardium. Arrhythmias are part of the broad spectrum of the disease, with atrial fibrillation (AF) as the most common. Due to the heterogeneity of cardiac amyloidosis, its real incidence is unknown, denoting an underdiagnosis and in many cases being hidden under the presentation of a common heart disease, which leads to silent progression and worse outcomes. We describe the clinical case of a patient with AF refractory to electrical cardioversion and ablation therapy in the context of cardiac transthyretin amyloidosis (ATTR), initially unnoticed and found as an incidental diagnosis. The purpose of this report is to review the association between AF and ATTR, its epidemiology, pathophysiology, signs and symptoms, diagnosis and treatment in order to provide medical staff with tools for a timely diagnosis of a poorly recognized disease.

Molecular Mechanism Study of β-amyloid Aggregation Inhibition by Transthyretin / 生物化学与生物物理进展

ObjectiveIt was reported that the transthyretin (TTR) has a neuroprotective effect on Alzheimer’s disease (AD), which is manifested by the ability of TTR to inhibit the pathological aggregation of amyloid beta protein (Aβ). In this work, we investigated the mechanism of the interactions between TTR and Aβ at the molecular level to reveal the neuroprotective effect of TTR on AD. MethodsProtein-protein docking was used to explore the models of interaction between different structural forms of TTR and Aβ, and molecular dynamics simulation was further applied to investigate the dynamic process of the interaction between the two. ResultsBoth TTR tetramer and monomer can interact with Aβ monomer, and the thyroxine-binding channel of TTR tetramer is the main binding site of Aβ monomer. In addition, the EF helix and EF loop of TTR tetramer were also able to bind Aβ monomer. When the TTR tetramer dissociates, the hydrophobic site of the internal TTR monomer is exposed, which has a strong affinity for Aβ monomer. For the interaction between Aβ aggregates and TTR, a higher degree of aggregation can be formed between TTR monomer and Aβ aggregates due to the β-sheet-rich property of TTR monomer and Aβ aggregates, which may therefore reduce the cytotoxicity of Aβ aggregates. ConclusionBoth TTR tetramer and monomer can inhibit Aβ aggregation by “sequestering” Aβ monomer, while TTR monomer can reduce the cytotoxicity of Aβ aggregates by forming large co-aggregation with Aβ aggregates. This work can provide an important theoretical basis for the design and discovery of anti-AD drugs based on the neuroprotective effects of TTR.

Real-life experience with inotersen at CEPARM, Hospital Universitário Clementino Fraga Filho, Universidade Federal do Rio de Janeiro / Experiência de vida-real com inotersena no CEPARM, Hospital Universitário Clementino Fraga Filho, Universidade Federal do Rio de Janeiro

Abstract Background Hereditary transthyretin amyloidosis (ATTRv) is an inherited, progressive, and fatal disease still largely underdiagnosed. Mutations in the transthyretin (TTR) gene cause the TTR protein to destabilize, misfold, aggregate, and deposit in body tissues, which makes ATTRv a disease with heterogeneous clinical phenotype. Objective To describe the long-term efficacy and safety of inotersen therapy in patients with ATTRv peripheral neuropathy (ATTRv-PN). Methods Patients who completed the NEURO-TTR pivotal study and the NEURO-TTR OLE open-label extension study migrated to the present study and were followed-up for at least 18 more months to an average of 67 months and up to 76 months since day 1 of the inotersen therapy (D1-first dose of inotersen). Disease progression was evaluated by standard measures. Results Ten ATTRv-PN patients with Val30Met mutation were included. The mean disease duration on D1 was of 3 years, and the mean age of the patients was of 46.8 years. During an additional 18-month follow up, neurological function, based on the Neuropathy Impairment Score and the Polyneuropathy Disability Score, functionality aspects (Karnofsky Performance Status), and nutritional and cardiac aspects were maintained. No new safety signs have been noted. Conclusion The treatment with inotersen was effective and well tolerated for the average of 67 months and up to 76 months. Our results are consistent with those of larger phase-III trials.

Resumo Antecedentes Amiloidose hereditária por transtirretina (ATTRv) é uma doença hereditária, progressiva e fatal ainda largamente subdiagnosticada. Mutações no gene transtirretina (TTR) promovem desestabilização, desdobramento, agregação e depósito da proteína TTR em tecidos do corpo, o que faz da ATTRv uma doença de fenótipo clínico heterogêneo. Objetivo Descrever a eficácia e segurança da terapia com inotersena no longo prazo em pacientes com neuropatia periférica ATTRv (ATTRv-PN). Métodos Pacientes que completaram o estudo pivotal NEURO-TTR e o estudo de extensão aberta NEURO-TTR OLE migraram para este estudo e foram acompanhados por no mínimo 18 meses adicionais, em média por 67 meses, e por até 76 meses, desde o dia 1 da terapia com inotersena (D1-primeira dose de inotersena). A progressão da doença foi avaliada por medidas padronizadas. Resultados Dez pacientes com ATTRv-PN com mutação Val30Met foram incluídos. A duração média da doença no D1 era de 3 anos, e a média de idade dos pacientes era de 46,8 anos. Durante o período de acompanhamento adicional de 18 meses, a função neurológica, baseada no Neuropathy Impairment Score e no Polyneuropathy Disability Score, os aspectos de funcionalidade (Karnofsky Performance Status), nutricional e cardíacos estavam mantidos. Não se observou nenhum novo sinal de segurança. Conclusão O tratamento com inotersena foi eficaz e bem tolerado por 67 meses em média, e por até 76 meses. Nossos resultados são consistentes com os de estudos maiores de fase III.

Recomendaciones de tratamiento y seguimiento en pacientes con amiloidosis hereditaria mediada por transtirretina / Recommendations for treatment and follow-up in patients with transthyretin-mediated hereditary amyloidosis

Resumen Introducción: La amiloidosis hereditaria mediada por transtirretina es una enfermedad autosómica dominante, con compromiso sistémico y progresivo, que altera la función de múltiples órganos, y se asocia con una alta morbilidad y mortalidad. Se presenta compromiso neurológico, cardiaco, autonómico, oftalmológico y nefrológico, entre otros, que se relacionan con el genotipo del paciente. Estas alteraciones afectan la calidad de vida y tienen una relación directa con la mortalidad temprana en estos pacientes. La neuropatía periférica es un marcador temprano de la enfermedad. Su identificación permite un tratamiento temprano con terapias modificadoras de la enfermedad, en busca de la estabilización de la progresión de la enfermedad, lo cual, acompañado de un seguimiento adecuado, tiene un impacto positivo en la calidad de vida de los pacientes y una prolongación de la expectativa de vida. Objetivo: Estructurar una serie de recomendaciones adecuadas al entorno local sobre el tratamiento y seguimiento en pacientes con amiloidosis hereditaria mediada por transtirretina. Materiales y método: Se utilizó la metodología Delphi y se estableció como punto de corte un 75% de favorabilidad. Resultados y conclusiones: Se plantearon una serie de recomendaciones basadas en la evidencia disponible y las recomendaciones internacionales, aplicables al entorno local, sobre métodos diagnósticos que faciliten la detección temprana del paciente afectado y los parámetros de inicio del tratamiento y el seguimiento que mejoren la calidad de vida, disminuyan las complicaciones y aumenten la expectativa de vida de estos pacientes.

Abstract Introducción: Transthyretin-mediated hereditary amyloidosis is an autosomal dominant disease with progressive systemic involvement that affects the function of multiple organs and is associated with high morbidity and mortality. Patients present neurological, cardiac, autonomic, ophthalmological and renal involvement, among others, related to the patient's genotype. These alterations affect quality of life and are directly related to early mortality. Peripheral neuropathy is an early marker of the disease. Its identification allows early treatment with disease-modifying therapies aimed at stabilizing disease progression, which, along with adequate follow-up, has a positive impact on patients' quality of life and prolongs life expectancy. Objective: To structure a series of recommendations appropriate to the local setting on treatment and follow-up in patients with hereditary transthyretin-mediated amyloidosis. Materials and methods: Delphi methodology was used, and a cut-off point of 75% favorability was established. Results and conclusions: A series of recommendations were presented based on the available evidence and international recommendations, applicable to the local setting, on diagnostic methods that facilitate early detection of the affected patient and the parameters for initiation of treatment and follow-up that improve the quality of life, decrease complications, and increase the life expectancy of these patients.

Progress in New Therapies Targeting the Pathogenesis of Cardiomyopathywith Hypertrophic Phenotype / 罕见病研究

Hypertrophic cardiomyopathy (HCM) is cardiomyopathy with a clinical phenotype of cardiac hypertrophy. The etiology includes genetically defective encoding sarcomeres, congenital metabolic diseases such as lysosomal storage diseases, systemic amyloidosis such as transthyretin amyloidosis(ATTR), and Fabry disease. Previous therapies did not target the etiology and pathogenesis and therefore were less effective. In recent years, treatments targeting different mechanisms of myocardial hypertrophy have achieved good results. Mavacamten can reduce myocardial contractility by inhibiting ATP activity, thereby significantly improving left ventricular outflow tract(LVOT) obstruction, cardiac contractility, ventricular tension, and limitting myocardial damage. By inhibiting the dissociation of transthyretin(TTR) and subsequent formation and deposition of the amyloid fibril, tafamidis can reduce the mortality and morbidity of patients with transthyretin cardiac amyloidosis(ATTR-CA). Gene silencing and gene editing technology can reduce abnormal TTR levels. Synthesis of α-galactosidase A by gene recombination technology in vitro can effectively reduce left ventricular mass index(LVMi), improve cardiac function, reduce angina attacks and decrease mortality of Fabry disease.

The Interpretation and Update of the Diagnosis Pathway of Chinese Expert Consensus on the Diagnosis and Treatment of Transthyretin Cardiac Amyoidosis / 罕见病研究

Transthyretin cardiac amyloidosis (ATTR-CA) is caused by the deposition of transthyretin(TTR) in the myocardial interstitium. Its clinical manifestations are mainly heart failure and arrhythmia, leading to poor life quality and low survival rate. Diagnosis is often delayed or missed due to the lack of disease awareness, the non-specific clinical symptom presentation of the disease, and inadequacy of non-invasive diagnostic methods and medications in the past. The recent availability of effective treatments makes the early recognition and diagnosis especially critical, because treatment is likely more effective earlier in the disease course. Therefore, it is crucial to establish a diagnosis and treatment strategy to facilitate the rapid and accurate identification of the disease. Based on the advances in research and experiences gained ATTR-CA, our team has developed a consensus on diagnosis and treatment for the disease. In this article, we interpret the key points and present the update of diagnostic process, providing clinicians with an overview of key aspects of ATTR-CA in China.

Characteristics of ocular involvement in Chinese patients with hereditary transthyretin amyloidosis / 中华眼底病杂志

Hereditary thyroxine protein amyloidosis (ATTRv) is one of the most common forms of systemic and ocular amyloidosis, characterized by autosomal dominant inheritance, incomplete penetrance, and diverse manifestations. ATTRv deposition leads to visual impairment and even irreversible visual loss, which has a negative impact on the quality of life of patients. The diagnostic rate of pathological examination and genetic testing in ATTRv patients is low, and the detection rate of systemic amyloid lesions is low. We need to increase our awareness of this disease and gain a deeper understanding of its systemic manifestations and corresponding examination methods; genetic testing is conducted on the proband's family to investigate the relationship between different gene mutations and eye manifestations. In the future, multidisciplinary consultations can be conducted to jointly diagnose and treat patients with ATTRv eye involvement, conducting large-scale and long-term follow-up studies on the early clinical characteristics, treatment plans, efficacy, possible complications, and early prevention, in order to improve clinical diagnosis rate, reduce misdiagnosis rate, and improve patient prognosis.

Clinical, genetic characteristics and follow-up in 14 patients with transthyretin familial amyloid polyneuropathy / 中华神经科杂志

Objective:To summarize the clinical and genetic characteristics in patients with transthyretin familial amyloid polyneuropathy (TTR-FAP).Methods:Fourteen unrelated TTR-FAP patients diagnosed at Xuanwu Hospital, Capital Medical University from September 2014 to February 2022 were retrospectively reviewed. The clinical manifestation, electrophysiology, cardiac function, biopsy and gene mutation were analyzed.Results:In the 14 patients (13 males, 1 female) diagnosed as TTR-FAP, the mean age at onset was 53.9 years (range: 33.0-71.0 years), with a mean course from symptom-onset to diagnosis of 4.1 years. The late-onset type occurred in 9 cases. Seven patients had a family history of TTR-FAP. Distal paresthesia of lower limbs was the commonest initial symptom (8 cases), with sensorimotor neuropathy and autonomic dysfunction seen initially in 4 and 2 cases, respectively. Cardiac involvement occurred in 6/8 of the patients. Nerve conduction studies indicated extremely axonal impairment with demyelinating features. Sural nerve biopsies showed moderate to severe axonal loss of myelinated fibers and the positive rate of Congo red staining was 8/14. Of 8 different TTR mutations detected, V50M was the most common (appearing in 5 cases). No obvious neuropathy progression was seen in the 5 patients who received tafamidis and 2 patients died of dyscrasia. Conclusions:TTR-FAP is more common in males, with sensorimotor axonal polyneuropathy, autonomic dysfunction and cardiac subclinical damage as the predominant symptoms. V50M is the commonest mutation. Tafamidis can delay the progression of disability.

Clinical features of transthyretin amyloid polyneuropathy caused by Ser77Tyr mutation / 中华神经医学杂志

Objective:To study the clinical features of transthyretin amyloid polyneuropathy (ATTR-PN) caused by Ser77Tyr mutation.Methods:The clinical data of a patient with ATTR-PN caused by Ser77Tyr mutation, admitted to our hospital from Department of Neurology, Mindong Hospital Affiliated to Fujian Medical University, were retrospectively analyzed. Literature on patients with ATTR-PN caused by Ser77Tyr mutation in Pubmed, Web of Science, CNKI and Wanfang databases and those with ATTR-PN caused by Val30Met mutation in Pubmed and Web of Science were searched and screened, and clinical characteristics of these patients were extracted. The differences of clinical characteristics among patients with ATTR-PN caused by Ser77Tyr or Val30Met mutations were compared.Results:(1) Transthyroxin ( TTR) gene Sanger sequencing results showed Ser77Tyr heterozygous pathogenic mutation; Congo red staining of biopsy sample in the patient 2.5 years after onset showed amyloid deposition. (2) Seventy-eight patients with ATTR-PN caused by Ser77Tyr mutation were summarized, they mostly had onset at 50-60 years old; male patients had higher incidence (74.4%); most patients (78.0%) had positive family history; most patients had sensory symptoms as initial symptom (72.0%), which gradually progressed to extensive peripheral nerve involvement and combined with widespread heart damage (96.4%) over several years; electrophysiological examination mainly showed axonal damage and carpal tunnel syndrome; the tissue biopsy had high positive rate(84.8%). (3) There were 192 and 96 patients with ATTR-PN caused by early-onset and late-onset Val30Met mutations, respectively; compared with patients with ATTR-PN caused by early-onset Val30Met mutation, patients with ATTR-PN caused by Ser77Tyr mutation had significantly higher incidence of deep sensory disturbance (28.6% vs. 58.5%, P<0.05). Compared with patients with ATTR-PN caused by late-onset Val30Met mutation, patients with ATTR-PN caused by Ser77Tyr mutation had increased incidence of mild sensory disturbance (56.3% vs. 75.0%) and decreased incidence of limb weakness (65.6% vs. 48.3%), with significant differences ( P<0.05). ATTR-PN patients caused by Ser77Tyr mutation had significantly higher incidence of carpal tunnel syndrome than ATTR-PN patients caused by early-onset and late-onset Val30Met mutations (75.4% vs. 10.8% and 25.0%) and significantly higher incidence of cardiac damage than ATTR-PN patients caused by early-onset Val30Met mutation (96.4% vs. 80.5%, P<0.05). Conclusion:Ser77Tyr mutation has some distinctive clinical features: relatively balanced damage of large and small fibers, prominent carpal tunnel syndrome, and obvious heart disease; early identification of these features and administration of tissue biopsy and gene detection are helpful for early diagnosis.

Advancements in pharmacological therapy for transthyretin cardiac amyloidosis and its comorbidities / 中国药房

Transthyretin cardiac amyloidosis myocardiopathy （ATTR-CM） is an infiltrative cardiomyopathy characterized by the deposition of amyloidogenic material in the myocardial interstitium due to the misfolding of monomers following the dissociation of unstable transthyretin （TTR） tetramers. Previous treatments for ATTR-CM lacked specificity，primarily targeting symptomatic management of heart failure and arrhythmias. In recent years，researchers have developed two major classes of drugs addressing the pathogenesis of ATTR-CM. The first class stabilizes TTR tetramer structure （such as tafamidis and acoramidis）， while the second class interferes with TTR synthesis （such as patisiran）. Among these，tafamidis has been confirmed as the only currently effective treatment for ATTR-CM，while other drugs are still in clinical trial stages with limited clinical evidence. Concerning the management of comorbidities in ATTR-CM，treatment mainly focuses on common cardiac comorbidities （such as heart failure and arrhythmias）. Traditional drugs used to improve heart failure prognosis （such as β-blockers and renin-angiotensin- receptor blocker），have not demonstrated prognosis improvement in ATTR-CM patients and may even lead to adverse reactions. For ATTR-CM patients with concurrent atrial fibrillation，anticoagulation therapy is recommended to prevent thrombus formation，and amiodarone can be used for rhythm control. Despite significant advancements in pharmaceutical treatments for ATTR-CM，the overall prognosis remains poor，necessitating further research into the pathogenesis and target development to enhance the prognosis of ATTR-CM patients.

Correlation analysis of serum TTR, RBP4 expressions and gestational metabolic syndrome / 中华内分泌外科杂志

Objective:To investigate the relationship between the expressions of serum trans thyroxine protein (TTR) , retinol binding protein 4 (RBP4) and metabolic syndrome of pregnancy (GMS) .Methods:A total of 103 patients with GMS from May. 2017 to Dec. 2019 were selected as the observation group, in addition, 100 healthy pregnant women with single pregnancy and no complications were selected as control group. Before pregnancy, the height and weight were detected. After the diagnosis of GMS, serum markers and blood pressure were detected. The levels of total cholesterol (TC) , triglyceride (TG) , low density lipoprotein cholesterol (LDL-C) , high density lipoprotein cholesterol (HDL-C) and fasting blood glucose (FBG) were detected by Hitachi 7600 automatic biochemical analyzer, and the expression levels of TTR and RBP4 in serum were detected by enzyme-linked immunosorbent assay (ELISA) . Receiver operating characteristic (ROC) curve was drawn to evaluate the diagnostic value of TTR and RBP4 in GMS. Multivariate Logistic regression model was used to analyze the influencing factors of GMS in pregnant women.Results:There was no significant difference in age or gestational weeks between the two groups ( P>0.05) . Compared with those in the control group, the levels of BMI, TC, TG, LDL-C, FBG, systolic blood pressure, diastolic blood pressure, serum TTR and RBP4 expression levels were higher in the observation group before pregnancy ( P<0.05) , while HDL-C was lower ( P<0.05) . The area under the curve (AUC) of TTR and RBP4 alone or combination in the diagnosis of GMS was 0.797, 0.816 and 0.898, respectively. The cut-off value of TTR was 284.91 mg/L, and the sensitivity and specificity were 63.10% and 89.00%, respectively. The cut-off value of RBP4 was 17.89 mg/L, and the sensitivity and specificity were 69.90% and 87.00%, respectively. The sensitivity and specificity of the combined diagnosis were 83.50% and 84.00% respectively. Multivariate Logistic regression analysis showed that high level of TTR and high level of RBP4 were independent risk factors of GMS in pregnant women ( P<0.05) . Conclusions:The expression levels of serum TTR and RBP4 in GMS patients are high, and they have certain diagnostic value for GMS. They are independent risk factors of GMS in pregnant women, which may provide new ideas for the early diagnosis and prevention of GMS.

Suspecting and diagnosing transthyretin amyloid cardiomyopathy (ATTR-CM) in India: An Indian expert consensus

Transthyretin cardiac amyloidosis (ATTR-CM) is a rare and under-recognized disorder characterized by the aggregation of transthyretin-derived insoluble amyloid fibrils in the myocardium. Heterogeneity of symptoms at presentation, makes its diagnosis often delayed. An expert panel gathered on a virtual platform across India to conduct a meeting for developing a guiding tool for ATTR-CM diagnosis. The panel recommended younger age (40 years) for suspecting ATTR-CM and thick-walled non-dilated hypokinetic ventricle was considered as one of the important red flags. Electrocardiogram (ECG) and echocardiography (ECHO) findings were recommended as primary tests to raise the suspicion while nuclear scintigraphy and hematological tests were recommended to confirm the diagnosis and rule out amyloid light-chain (AL) amyloidosis. Cardiac magnetic resonance (CMR) and biopsy were recommended in case of ambiguity in the presence of red flags. Considering the lack of expert guidelines in the Indian scenario, a standardized diagnostic algorithm was also proposed.

Homage to Paula Coutinho ­ a pioneer in portuguese and worldwide neurogenetics / Homenagem a Paula Coutinho ­ uma pioneira da neurogenética portuguesa e mundial

This is a tribute to an outstanding Portuguese neurologist and researcher, Paula Coutinho (1941-2022), who specialized in the care and study of people with familial amyloidotic polyneuropathy and Machado-Joseph disease which she helped define. As a result, she collaborated with the inauguration of the Centro de Estudos de Paramiloidose Antônio Rodrigues de Mello (CEPARM) founded in 1984 at the University Hospital of the Federal University of Rio de Janeiro. Since then, we admire her commitment to science and patients.

Esta é uma homenagem a uma notável neurologista e pesquisadora portuguesa, Paula Coutinho (1941-2022), que se especializou no cuidado e estudo de pessoas com polineuropatia amiloidótica familiar e doença Machado-Joseph, que ela ajudou a definir. Como resultado, colaborou com a inauguração do Centro de Estudos de Paramiloidose Antônio Rodrigues de Mello (CEPARM) fundado em 1984 no Hospital Universitário da Universidade Federal do Rio de Janeiro. Desde então, admiramos o seu compromisso com a ciência e os pacientes.

Ophthalmological manifestations of hereditary transthyretin amyloidosis / Manifestações oftalmológicas da amiloidose hereditária por transtirretina

ABSTRACT Transthyretin familial amyloidosis is the most common form of inherited systemic amyloidosis worldwide. The condition develops secondary to more than 100 different point mutations in the transthyretin gene (18q12.1). The mutations lead to abnormal amyloid deposits, mainly in the heart and peripheral nerves. Leptomeningeal and mainly ocular involvement is common. Although there are several different types of treatment available, ocular involvement, which occurs also in liver transplant recipients, remains a major challenge, progressing even in liver transplant recipients. Patients with ocular involvement require efficient ophthalmological follow-up to prevent vision loss. In this review, different forms of ocular involvement characterizing the subtypes of transthyretin mutations were described, and the effects of different treatments were summarized. Further research is necessary to fully elucidate these issues.

RESUMO A amiloidose familiar por transtirretina é a forma mais comum de amiloidose sistêmica hereditária mundialmente. A condição é secundária a mais de 100 mutações ponto diferentes no gene da transtirretina (18q12.1). Mutações levam a depósitos anormais de amilóide principalmente no coração e nos nervos periféricos. O envolvimento leptomeníngeo, e principalmente ocular também é comum. Apesar do advento de várias formas diferentes de tratamento, o envolvimento ocular ainda é um grande problema, progredindo mesmo em pacientes submetidos à transplante hepático. Nesta revisão, avaliamos as diferentes formas de envolvimento ocular presentes entre os subtipos de mutações da transtirretina e os efeitos dos diferentes tratamentos disponíveis. O envolvimento ocular é desafiador na amiloidose familiar por transtirretina, exigindo acompanhamento oftalmológico eficiente para mitigar a perda de visão. Mais pesquisas são necessárias para auxiliar na resolução dessas questões.

Polineuropatía por amiloidosis por transtiretina de inicio tardío. Caso clínico / Late-onset hereditary transthyretin amyloidosis with polyneuropathy. Report of one case

Hereditary transthyretin amyloidosis is a multisystemic autosomal dominant genetic disorder characterized by progressive distal sensory-motor polyneuropathy or restrictive cardiomyopathy, secondary to amyloid deposits. Its pathogenesis lies in the TTR gene mutation, and the Val50Met mutation is the most frequent. Patients have significant differences in the onset and severity of clinical presentation according to their country of origin. The diagnosis of this pathology is complex, even more in countries where it is not considered endemic. However, early suspicion and management are essential to improve survival and avoid unnecessary diagnostic and therapeutic strategies. We report a 69-year-old woman who presented a sensory-motor polyneuropathy, predominantly sensory, associated with distal neuropathic pain and bilateral vitritis. The history of her Italian father with polyneuropathy of unspecified etiology stood out. A vitreous biopsy identified amyloid substance deposits (congo red positive). These were also confirmed on a superficial peroneal nerve biopsy. During the etiological study of her polyneuropathy, an increased Kappa/Lambda index of 2.55 mg/L stood out. Therefore, light chain amyloidosis was suspected, and chemotherapy treatment was indicated without favorable response. After 10 years of progressive neurological and ophthalmological involvement, a genetic study confirmed the first case of late-onset hereditary transthyretin amyloidosis Val50Met with polyneuropathy in Chile.

Primer uso de tafamidis en amiloidosis cardíaca TTR en Uruguay / First use of tafamidis in cardiac amyloidosis TTR in Uruguay / Primeiro uso de tafamidis em amiloidose cardíaca TTR no Uruguai

La amiloidosis cardíaca es una entidad con creciente reconocimiento, la variedad por transtiretina es la que más se diagnostica en la tercera edad de la vida. Hay reciente disponibilidad de fármacos que mejoran el pronóstico y la calidad de vida de los pacientes. Presentamos un caso de amiloidosis por transtiretina donde se usó por primera vez en nuestro país el fármaco tafamidis aprobado para el tratamiento de esta enfermedad.

Cardiac amyloidosis is an entity on increasing recognition, transthyretin variety is the most diagnosed in the third age. There is a recent availability of drugs that can improve the prognosis and quality of life of these patients. We present a case of transthyretin amyloidosis and the first use of tafamidis in our country.

A amiloidose cardíaca é uma entidade em crescente reconhecimento, a variedade transtiretina é a mais diagnosticada em idosos. Há disponibilidade recente de medicamentos que melhoram o prognóstico e a qualidade de vida dos pacientes. Apresentamos um caso de amiloidosis transteretina onde o medicamento tafamidis aprovado para esta doença foi utilizado pela primeira vez em nosso país.

Diagnóstico de amiloidosis sistémica: bases hematológicas útiles para el cardiólogo clínico / Diagnosis in systemic amiloydosis: useful hematological bases for the clinical cardiologist / Diagnóstico de amiloidose sistémica: bases hematológicas úteis para o cardiologista clínico

Las amiloidosis son un grupo heterogéneo de patologías caracterizado por el depósito extracelular de proteínas fibrilares anormalmente plegadas que se depositan en los tejidos y ocasionan su disfunción. La calidad y expectativa de vida depende del órgano afectado y del grado de compromiso, la afectación cardíaca es la principal determinante de la sobrevida y calidad de vida. El diagnóstico requiere la biopsia tisular y tipificación de la proteína. Su detección tardía se asocia a inferior pronóstico y sobrevida. La forma más común de amiloidosis es la causada por depósito de cadenas livianas monoclonales (AL), para la cual nuevos agentes de inmuno y quimioterapia dirigidas a suprimir la clona de células plasmáticas han demostrado mejorar la sobrevida. Para la amiloidosis por transtiretina (ATTR), segunda en frecuencia, existen terapias estabilizadoras de la proteína y terapias dirigidas a detener su síntesis a través del silenciamiento genético. Esta revisión se dirige a describir las bases hematológicas útiles para el cardiólogo clínico.

The amyloidoses are a heterogeneous group of diseases caused by the extracellular deposition of abnormally folded fibrillar proteins in organs and tissues, causing their dysfunction. The quality and life expectancy depend on the affected organ, with cardiac involvement being the main determinant of survival and quality of life. Diagnosis requires tissue biopsy and protein typing. Its late detection is associated with a lower prognosis and survival. The most common form of amyloidosis is caused by monoclonal light chain (AL) deposition, for which new immunological agents and chemotherapy aimed at suppressing plasma cell cloning have been shown to improve survival. For transthyretin amyloidosis (ATTR), the second in frequency, there are protein-stabilizing therapies and therapies aimed at stopping its synthesis through genetic silencing. This review focuses on the hematological bases for the clinical cardiologist.

As amiloidoses são um grupo heterogêneo de patologias caracterizadas pela deposição extracelular de proteínas fibrilares anormalmente dobradas, que se depositam nos tecidos, causando sua disfunção. A qualidade e expectativa de vida dependem do órgão afetado e do grau de comprometimento, sendo o acometimento cardíaco o principal determinante da sobrevida e qualidade de vida. O diagnóstico requer biópsia tecidual e tipagem de proteínas. Sua detecção tardia está associada a um menor prognóstico e sobrevida. A forma mais comum de amiloidose é causada pela deposição monoclonal de cadeia leve (AL), para a qual novos agentes imuno e quimioterápicos destinados a suprimir a clonagem de plasmócitos demonstraram melhorar a sobrevida. Para a amiloidose por transtirretina (ATTR), segunda em frequência, existem terapias estabilizadoras de proteínas e terapias destinadas a interromper sua síntese por meio do silenciamento genético. Esta revisão enfoca a amiloidose sistêmica, com foco em bases hematológicas úteis para o cardiologista clínico.

An Autopsy Case of Transthyretin-Related Cardiac Amyloidosis (TTR-CA), Which Fell into Low-Output Syndrome after Cardiac Surgery / 日本心臓血管外科学会雑誌

We present the case of 83-year-old male patient. He was under observation as an outpatient with mild to moderate aortic stenosis and regurgitation since 75 years old. He underwent surgery because of repeated hospitalization by heart failure due to progressive aortic valve stenosis and regurgitation, mitral valve stenosis and regurgitation, and tricuspid regurgitation. Elective aortic valve replacement, mitral valve replacement and tricuspid valve repair was performed. Even though his condition after surgery was stable, suddenly feature like low output syndrome appeared on day 6, and led to a mortality on day 8 after operation. Ejection fraction was kept above 50 percent before and after surgery, which indicated to Heart Failure with preserved Ejection Fraction (HFpEF). After autopsy examination, by immunohistochemical staining identified transthyretin, we demonstrated previously undiagnosed transthyretin-related cardiac amyloidosis (TTR-CA).

Neurosonographic characteristics of peripheral nerve in transthyretin familial amyloid polyneuropathy / 中华神经科杂志

Objective:To study peripheral nerve morphology in patients with transthyretin familial amyloid polyneuropathy (TTR-FAP) using high-frequency ultrasonography (HFUS), and to evaluate the value of HFUS in diagnosis of TTR-FAP.Methods:Thirty-eight patients with TTR-FAP diagnosed by gene detection and 23 normal controls from June 2015 to June 2021 in Peking University First Hospital were enrolled in this study. Consecutive ultrasonography scanning was performed in 6 pairs of nerves of bilateral limbs with 30 sites. The cross sectional area (CSA), CSA variability and inter-nerve CSA variability data of the two groups were retrospectively calculated and compared.Results:Compared with the normal controls, TTR-FAP patients showed larger CSA values at most nerve sites of both upper and lower limbs, and there were statistically significant differences at M1(median nerve) [8.55 (6.90, 9.40) mm 2vs 10.05 (9.10, 14.10) mm 2, Z=5.58, P<0.001], M3 (median nerve) [(6.98±1.66) mm 2vs (9.29±2.30) mm 2, t=6.28, P<0.001], M5 (median nerve) [(8.91±1.81) mm 2vs (14.33±4.20) mm 2, t=9.84, P<0.001], U5 (ulnar nerve) [(6.20±1.93) mm 2vs (9.34±2.85) mm 2, t=7.31, P<0.001], Sci1 (sciatic nerve) [(53.50±17.24) mm 2vs (79.74±20.75) mm 2, t=7.57, P<0.001], Sci2 (sciatic nerve) [(53.66±14.21) mm 2vs (73.98±19.21) mm 2, t=6.82, P<0.001] and Tib (tibial nerve) [(31.05±8.43) mm 2vs (46.29±13.14) mm 2, t=7.84, P<0.001] sites. There was no statistically significant difference in CSA at each site among the different subtypes and disease severity of TTR-FAP patients ( P>0.05). There was no statistically significant difference in CSA-variability of the median and ulnar nerves between the patients with TTR-FAP and the normal controls ( P>0.05). The side-to-side difference ratio of intra-nerve CSA variability of the ulnar nerve in the patients with TTR-FAP was smaller than that of the normal controls (1.15±0.10 vs 1.46±0.43, t=3.43, P=0.002), whereas no statistically significant difference of that in the median nerve was found between the two groups ( P>0.05). Conclusions:The most pronounced peripheral nerve thickening in the proximal limb segments with no signs of asymmetric distribution or lateralization is confirmed by HFUS in TTR-FAP patients and should be regarded as a marker of TTR-FAP. HFUS has clinical value in diagnosis of peripheral neuropathy in TTR-FAP patients.