THAOS: gastrointestinal manifestations of transthyretin amyloidosis - common complications of a rare disease

Impact of Baseline Neuropathy Severity on Vutrisiran Treatment Response in the Phase 3 HELIOS-A Study

INTRODUCTION

Hereditary transthyretin (ATTRv, v for variant) amyloidosis is a rare, progressive, fatal disease with multisystem manifestations, caused by pathogenic variants in the transthyretin (TTR) gene. Vutrisiran, an RNA interference therapeutic that results in rapid TTR knockdown, improved neuropathy and quality of life (QOL) versus external placebo in patients with ATTRv amyloidosis with polyneuropathy in the phase 3 HELIOS-A study (NCT03759379). This post hoc analysis evaluates the impact of baseline neuropathy severity on response to vutrisiran treatment.

METHODS

Patients were randomized (3:1) to vutrisiran (n = 122; 25 mg subcutaneous injection once every 3 months) or patisiran (n = 42; 0.3 mg/kg intravenous infusion once every 3 weeks), which served as a reference group. In this post hoc analysis, patients were grouped into quartiles of increasing baseline Neuropathy Impairment Score (NIS): Quartile (Q)1 ≥ 5.0 to ≤ 20.5; Q2 > 20.5 to ≤ 44.1; Q3 > 44.1 to ≤ 73.1; Q4 > 73.1 to ≤ 127.0. Mean change from baseline to Month 18 was summarized by quartile for a range of efficacy endpoints.

RESULTS

Across all baseline NIS quartiles, vutrisiran demonstrated benefit versus external placebo in measures of neuropathy severity (modified NIS + 7), QOL (Norfolk Quality of Life-Diabetic Neuropathy), disability (Rasch-built Overall Disability Scale), gait speed (10-m walk test), and nutritional status (modified body mass index). Overall, patients in lower versus higher NIS quartiles (less severe neuropathy) at baseline maintained better scores at Month 18. The external placebo group progressively worsened in all measures at Month 18.

CONCLUSIONS

Vutrisiran demonstrated benefit in neurologic function and other key efficacy measures versus external placebo across all four baseline neuropathy severity quartiles. Patients initiating vutrisiran earlier in their disease course retained the highest neurologic function level after 18 months, highlighting the importance of early diagnosis and treatment.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov: NCT03759379.

Identification and management of gastrointestinal manifestations of hereditary transthyretin amyloidosis: Recommendations from an Italian group of experts

Gastrointestinal manifestations are common across all hereditary transthyretin amyloidosis (ATTRv) genotypes. However, they are poorly specific, and their recognition as part of ATTRv is difficult, resulting in misdiagnosis with more common conditions. Moreover, delays in diagnosis occur because of fragmented knowledge, a shortage of centers of excellence and specialists dedicated to ATTRv management, and the scarce involvement of gastroenterologists in multidisciplinary teams. A group of Italian gastroenterologists with experience in the management of ATTRv took part in a project aimed at assessing the awareness of ATTRv among the community of Italian gastroenterologists through an online survey and providing education about practical aspects of ATTRv management. Survey results reported low participation, and very few patients with ATTRv were cared for by gastroenterologists. This highlights the need for greater attention to rare diseases in gastroenterology and emphasizes increasing awareness of ATTRv and diagnostic suspicion. Based on the experts' recommendations, a diagnosis of ATTRv should be suspected when at least one of the 'red flags' is detected. Subsequently, it is suggested to promptly ask for genetic testing and exclude a serum and urinary monoclonal protein, even before the detection of amyloid in biopsy samples, particularly in non-endemic areas.

Altered gut microbiota in Taiwanese A97S predominant transthyretin amyloidosis with polyneuropathy

Increasing evidence suggests that gut microbiota alterations are related to development and phenotypes of many neuropsychiatric diseases. Here, we evaluated the fecal microbiota and its clinical correlates in patients with hereditary transthyretin amyloidosis (ATTRv) and polyneuropathy. Fecal microbiota from 38 ATTRv patients and 39 age-matched controls was analyzed by sequencing 16S V3-V4 ribosomal RNA, and its relationships with clinical characteristics of polyneuropathy and cardiomyopathy were explored. The familial amyloidotic polyneuropathy stage was stage I, II, and III in 13, 18, and 7 patients. 99mTc-PYP SPECT showed a visual score of 2 in 15 and 3 in 21 patients. The gut microbiota of ATTRv patients showed higher alpha diversity (ASV richness and Shannon effective numbers) and dissimilar beta diversity compared to controls. Relative abundance of microbiota was dominated by Firmicutes and decreased in Bacteroidetes in ATTRv patients than in controls. Patients with more myocardial amyloid deposition were associated with increased alpha diversity, and the abundance of Clostridia was significantly correlated with pathophysiology of polyneuropathy in ATTRv patients. These findings demonstrated alterations in the gut microbiota, especially Firmicutes, in ATTRv. The association between altered microbiota and phenotypes of cardiomyopathy and polyneuropathy might suggest potential contributions of gut microbiota to ATTRv pathogenesis.

Genetic screening for hereditary transthyretin amyloidosis with polyneuropathy in western Sicily: Two years of experience in a neurological clinic

BACKGROUND AND PURPOSE

Hereditary transthyretin amyloidosis with polyneuropathy (ATTRv-PN) is caused by mutations in the TTR gene, leading to misfolded monomers that aggregate generating amyloid fibrils.

METHODS

A prospective systematic genetic screening for ATTRv-PN was proposed in patients presenting with a sensory-motor idiopathic polyneuropathy and two or more "red flags" among the following: family history of polyneuropathy or cardiopathy, bilateral carpal tunnel syndrome, cardiac insufficiency, renal amyloidosis, lumbar tract stenosis, autonomic dysfunction, idiopathic gastrointestinal disease, amyloid deposits on biopsy, and vitreous opacities. The detection rate was calculated, and nonparametric analyses were carried out to underline differences among screened positive versus negative patients.

RESULTS

In the first step, 145 suspected patients underwent genetic testing, revealing a diagnosis of ATTRv-PN in 14 patients (10%). Then, cascade screening allowed early recognition of 33 additional individuals (seven symptomatic ATTRv-PN patients and 26 presymptomatic carriers) among 84 first-degree relatives. Patients with a positive genetic test presented a higher frequency of unexplained weight loss, gastrointestinal symptoms, and family history of cardiopathy.

CONCLUSIONS

A systematic screening for ATTRv-PN yielded an increased recognition of the disease in our neurological clinic. Unexplained weight loss associated with axonal polyneuropathy had the highest predictive value in the guidance of clinical suspicion. A focused approach for the screening of ATTRv-PN could lead to an earlier diagnosis and identification of asymptomatic carriers, who will be promptly treated after a strict follow-up at the clinical onset.

Peripheral Nervous, Hepatic, and Gastrointestinal Endpoints for AL Amyloidosis Clinical Trials: Report from the Amyloidosis Forum Multi-organ System Working Group

Systemic immunoglobulin light chain (AL) amyloidosis is a heterogeneous rare disease driven by a destructive monoclonal gammopathy and typified by misfolded immunoglobulin light and/or heavy chains which aggregate and deposit in organs as insoluble amyloid fibrils. Disease heterogeneity is driven by the degree of multi-systemic involvement; cardiac, renal, neurological, and gastrointestinal (GI) systems are affected to varying degrees in different patients. While prognosis is primarily driven by hematologic response to treatment and outcomes associated with cardiac events and overall survival, the involvement of the peripheral nervous, hepatic, and GI systems can also have a significant impact on patients. The Amyloidosis Forum ( https://amyloidosisforum.org ) is a public-private partnership between the nonprofit Amyloidosis Research Consortium ( www.arci.org ) and the US Food and Drug Administration (FDA) Center for Drug Evaluation and Research formed to advance drug development for the treatment of systemic amyloid disorders. A series of virtual workshops focused on the development of novel, patient-relevant endpoint components and analytical strategies for clinical trials in AL amyloidosis. This review summarizes the proceedings and recommendations of the Multi-Systemic Working Group which identified, reviewed, and prioritized endpoints relevant to the impacts of AL amyloidosis on the peripheral nervous, hepatic, and GI systems. The Working Group comprised amyloidosis experts, patient representatives, statisticians, and representatives from the FDA, Medicines and Healthcare products Regulatory Agency (MHRA), and pharmaceutical companies. Prioritized neuropathy/autonomic endpoints included a modified form of the Neuropathy Impairment Score (NIS + 7) and the Composite Autonomic Symptom Score (COMPASS-31), respectively. Alkaline phosphatase was identified as the most relevant indicator of liver involvement and disease progression. Following extensive review of potential GI endpoints, the Working Group identified multiple exploratory endpoints. These recommended components will be further explored through evaluation of clinical trial datasets and possible integration into composite endpoint analysis.

Severe chronic diarrhoea caused by hereditary transthyretin amyloidosis

Amyloidosis includes a heterogeneous group of diseases caused by the extracellular deposition of insoluble fibrillar proteins, leading to multiple organ dysfunction and a poor life expectancy. In the early stages of amyloidosis, gastrointestinal (GI) symptoms are uncommon. We describe a rare case of hereditary transthyretin amyloidosis (ATTRv) with involvement of the heart, nervous system and GI tract. A man in his 60s was hospitalised due to chronic diarrhoea, orthostatic hypotension, malabsorption and weight loss. An organic origin for the diarrhoea was suspected, but the most common causes were ruled out. The review of GI biopsies and an abdominal fat aspirate confirmed the diagnosis of amyloidosis. The diagnosis of ATTRv amyloidosis with GI presentation is challenging, especially in the early stages, and misdiagnosis is common. The recent approval of therapies emphasises the importance of early diagnosis to prevent irreversible organ damage.

Optimal practices for the management of hereditary transthyretin amyloidosis: real-world experience from Japan, Brazil, and Portugal

Hereditary transthyretin (ATTRv) amyloidosis is a rare and autosomal dominant disorder associated with mutations in the transthyretin gene. Patients present with diverse symptoms related to sensory, motor, and autonomic neuropathy, as well as gastrointestinal, ocular, cardiac, renal and orthopedic symptoms, resulting from the deposition of transthyretin amyloid fibrils in multiple organs. The progressive nature of ATTRv amyloidosis necessitates pre- and post-onset monitoring of the disease. This review article is primarily based on a collation of discussions from a medical advisory board meeting in August 2021. In this article, we summarize the best practices in amyloidosis centers in three major endemic countries for ATTRv amyloidosis (Japan, Brazil, and Portugal), where most patients carry the Val30Met mutation in the transthyretin gene and the patients' genetic background was proven to be the same. The discussions highlighted the similarities and differences in the management of asymptomatic gene mutation carriers among the three countries in terms of the use of noninvasive tests and tissue biopsies and timing of starting the investigations. In addition, this article discusses a set of practical tests and examinations for monitoring disease progression applicable to neurologists working in diverse medical settings and generalizable in non-endemic countries and areas. This set of assessments consists of periodic (every 6 to 12 months) evaluations of patients' nutritional status and autonomic, renal, cardiac, ophthalmologic, and neurological functions. Physical examinations and patient-reported outcome assessments should be also scheduled every 6 to 12 months. Programs for monitoring gene mutation carriers and robust referral networks can aid in appropriate patient management in pre- to post-onset stages. For pre- and post-symptom onset testing for ATTRv amyloidosis, various noninvasive techniques are available; however, their applicability differs depending on the medical setting in each country and region, and the optimal option should be selected in view of the clinical settings, medical environment, and available healthcare resources in each region.

Hereditary transthyretin amyloidosis: a comprehensive review with a focus on peripheral neuropathy

Amyloidoses represent a group of diseases characterized by the pathological accumulation in the extracellular area of insoluble misfolded protein material called "amyloid". The damage to the tissue organization and the direct toxicity of the amyloidogenic substrates induce progressive dysfunctions in the organs involved. They are usually multisystem diseases involving several vital organs, such as the peripheral nerves, heart, kidneys, gastrointestinal tract, liver, skin, and eyes. Transthyretin amyloidosis (ATTR) is related to abnormalities of transthyretin (TTR), a protein that acts as a transporter of thyroxine and retinol and is produced predominantly in the liver. ATTR is classified as hereditary (ATTRv) and wild type (ATTRwt). ATTRv is a severe systemic disease of adults caused by mutations in the TTR gene and transmitted in an autosomal dominant manner with incomplete penetrance. Some pathogenic variants in TTR are preferentially associated with a neurological phenotype (progressive peripheral sensorimotor polyneuropathy); others are more frequently associated with restrictive heart failure. However, many mutations express a mixed phenotype with neurological and cardiological involvement. ATTRv is now a treatable disease. A timely and definite diagnosis is essential in view of the availability of effective therapies that have revolutionized the management of affected patients. The purpose of this review is to familiarize the clinician with the disease and with the correct diagnostic pathways in order to obtain an early diagnosis and, consequently, the possibility of an adequate treatment.

Impact of Vutrisiran on Quality of Life and Physical Function in Patients with Hereditary Transthyretin-Mediated Amyloidosis with Polyneuropathy

INTRODUCTION

Hereditary transthyretin (ATTRv; v for variant) amyloidosis, also known as hATTR amyloidosis, is a progressive and fatal disease associated with rapid deterioration of physical function and patients' quality of life (QOL). Vutrisiran, a subcutaneously administered RNA interference (RNAi) therapeutic that reduces hepatic production of transthyretin, was assessed in patients with ATTRv amyloidosis with polyneuropathy in the pivotal HELIOS-A study.

METHODS

The phase 3 open-label HELIOS-A study investigated the efficacy and safety of vutrisiran in patients with ATTRv amyloidosis with polyneuropathy, compared with an external placebo group from the APOLLO study of the RNAi therapeutic patisiran. Measures of QOL and physical function were assessed.

RESULTS

At month 18, vutrisiran improved Norfolk Quality of Life-Diabetic Neuropathy (Norfolk QOL-DN) total score (least squares mean difference [LSMD] in change from baseline [CFB]: -21.0; p = 1.84 × 10-10) and Norfolk QOL-DN domain scores, compared with external placebo. This benefit relative to external placebo was evident across all baseline polyneuropathy disability (PND) scores and most pronounced in patients with baseline PND scores I-II. Compared with external placebo, vutrisiran also demonstrated benefit in EuroQoL-Visual Analog Scale (EQ-VAS) score (LSMD in CFB: 13.7; nominal p = 2.21 × 10-7), 10-m walk test (LSMD in CFB: 0.239 m/s; p = 1.21 × 10-7), Rasch-built Overall Disability Score (LSMD in CFB: 8.4; p = 3.54 × 10-15), and modified body mass index (mBMI) (LSMD in CFB: 140.7; p = 4.16 × 10-15) at month 18. Overall, Norfolk QOL-DN, EQ-VAS, and mBMI improved from pretreatment baseline with vutrisiran, whereas all measures worsened from baseline in the external placebo group. At month 18, Karnofsky Performance Status was stable/improved from baseline in 58.2/13.1% with vutrisiran versus 34.7/8.1% with external placebo.

CONCLUSION

Vutrisiran treatment provided significant clinical benefits in multiple measures of QOL and physical function in patients with ATTRv amyloidosis with polyneuropathy. Benefits were most pronounced in patients with earlier-stage disease, highlighting the importance of early diagnosis and treatment.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov: NCT03759379.

The estimation of health state utility values in rare diseases: do the approaches in submissions for NICE technology appraisals reflect the existing literature? A scoping review

BACKGROUND

Rare diseases negatively impact patients' quality of life, but the estimation of health state utility values (HSUVs) in research studies and cost-utility models for health technology assessment is challenging.

OBJECTIVES

This study compared the methods for estimating the HSUVs included in manufacturers' submissions of orphan drugs to the National Institute for Health and Care Excellence (NICE) with those of published studies addressing the same rare diseases to understand whether manufacturers fully exploited the existing literature in developing their economic models.

METHODS

All NICE Technology Appraisal (TA) and Highly Specialized Technologies (HST) guidance documents of non-cancer European Medicines Agency (EMA) orphan medicinal products were reviewed and compared with any published primary studies, retrieved via PubMed until November 2020, and estimating HSUVs for the same conditions addressed in manufacturers' submissions.

RESULTS

We identified 22 NICE TA/HST appraisal reports addressing 19 different rare diseases. Sixteen reports presented original HSUVs estimated using EQ-5D or Health Utility Index (n = 12), direct methods (n = 2) or mapping (n = 2), while the other six included values obtained from the literature only. In parallel, we identified 111 published studies: 86.6% used preference-based measures (mainly EQ-5D, 60.7%), 12.5% direct techniques, and 2.7% mapping. The collection of values from non-patient populations (using 'vignettes') was more frequent in manufacturers' submissions than in the literature (22.7% vs. 8.0%).

CONCLUSIONS

The agreement on methodological choices between manufacturers' submissions and published literature was only partial. More efforts should be made by manufacturers to accurately reflect the academic literature and its methodological recommendations in orphan drugs submissions.

The Transthyretin Amyloidosis - Quality of Life (ATTR-QOL) Questionnaire: Development of a Conceptual Model and Disease-Specific Patient-Reported Outcome Measure

Purpose

Patients with transthyretin amyloidosis (ATTR) experience a wide variety of symptoms and impacts on health-related quality of life (HRQoL). However, the lack of an ATTR-specific patient-reported outcome (PRO) measure has made consistent measurement of HRQoL in ATTR challenging. This paper describes the development of a conceptual model and subsequent content for the Transthyretin Amyloidosis - Quality of Life Questionnaire (ATTR-QOL), an ATTR-specific PRO measure.

Methods

This was a cross-sectional, non-interventional, US-based study. The study design included three stages: 1) a targeted literature review followed by qualitative data collection with patients and experts; 2) development of a conceptual model and PRO measure; and 3) review of the PRO measure using a modified Delphi method, translatability assessment, and interviews with patients and experts. Revisions were made to the measure after each round of review.

Results

Forty-four patients and 29 experts participated in this study. The conceptual model included two primary concepts of interest: symptoms (cardiac, neuropathic-peripheral, neuropathic-autonomic, and other) and impacts (eg, physical, role, and mental/emotional functioning). Seventy-two items were created (32 symptoms; 40 impacts) to align with the model. A recall period of one month was selected based on participant input.

Conclusion

The ATTR-QOL was created with significant patient involvement and guidance from a multidisciplinary group of experts. The mix of patient and clinical perspectives helped to ensure a balanced representation of all relevant disease experiences and clinical specialties. With further refinement from psychometric testing, the ATTR-QOL will provide a standard, comprehensive measure for all ATTR-specific research including both clinical trials and clinical practice.

Machine Learning for Early Diagnosis of ATTRv Amyloidosis in Non-Endemic Areas: A Multicenter Study from Italy

BACKGROUND

Hereditary transthyretin amyloidosis with polyneuropathy (ATTRv) is an adult-onset multisystemic disease, affecting the peripheral nerves, heart, gastrointestinal tract, eyes, and kidneys. Nowadays, several treatment options are available; thus, avoiding misdiagnosis is crucial to starting therapy in early disease stages. However, clinical diagnosis may be difficult, as the disease may present with unspecific symptoms and signs. We hypothesize that the diagnostic process may benefit from the use of machine learning (ML).

METHODS

397 patients referring to neuromuscular clinics in 4 centers from the south of Italy with neuropathy and at least 1 more red flag, as well as undergoing genetic testing for ATTRv, were considered. Then, only probands were considered for analysis. Hence, a cohort of 184 patients, 93 with positive and 91 (age- and sex-matched) with negative genetics, was considered for the classification task. The XGBoost (XGB) algorithm was trained to classify positive and negative TTR mutation patients. The SHAP method was used as an explainable artificial intelligence algorithm to interpret the model findings.

RESULTS

diabetes, gender, unexplained weight loss, cardiomyopathy, bilateral carpal tunnel syndrome (CTS), ocular symptoms, autonomic symptoms, ataxia, renal dysfunction, lumbar canal stenosis, and history of autoimmunity were used for the model training. The XGB model showed an accuracy of 0.707 ± 0.101, a sensitivity of 0.712 ± 0.147, a specificity of 0.704 ± 0.150, and an AUC-ROC of 0.752 ± 0.107. Using the SHAP explanation, it was confirmed that unexplained weight loss, gastrointestinal symptoms, and cardiomyopathy showed a significant association with the genetic diagnosis of ATTRv, while bilateral CTS, diabetes, autoimmunity, and ocular and renal involvement were associated with a negative genetic test.

CONCLUSIONS

Our data show that ML might potentially be a useful instrument to identify patients with neuropathy that should undergo genetic testing for ATTRv. Unexplained weight loss and cardiomyopathy are relevant red flags in ATTRv in the south of Italy. Further studies are needed to confirm these findings.

Amylo-AFFECT-QOL, a self-reported questionnaire to assess health-related quality of life and to determine the prognosis in cardiac amyloidosis

Background and aims

Self-reported questionnaires are useful for estimating the health-related quality of life (HR-QoL), impact of interventions, and prognosis. To our knowledge, no HR-QoL questionnaire has been developed for cardiac amyloidosis (CA). This study aimed to validate Amylo-AFFECT-QOL questionnaire to assess HR-QoL and its prognostic value in CA.

Methods

A self-reported questionnaire, “Amylo-AFFECT” had been designed and validated for CA symptoms evaluation and screening by physicians. It was adapted here to assess HR-QoL (Amylo-AFFECT-QOL) and its prognostic value in CA. To validate the theoretical model, internal consistency and convergent validity were assessed, particularly correlations between Amylo-AFFECT-QOL and the HR-QoL Minnesota Living Heart Failure (MLHF) questionnaire.

Results

Amylo-AFFECT-QOL was completed by 515 patients, 425 of whom (82.5%) had CA. Wild-type and hereditary transthyretin amyloidosis (ATTRwt and ATTRv) and immunoglobulin light-chain amyloidosis (AL) were diagnosed in 47.8, 14.7, and 18.8% of cases, respectively. The best HR-QoL evaluation was obtained with five dimensions: “Heart failure,” “Vascular dysautonomia,” “Neuropathy,” “Ear, gastrointestinal, and urinary dysautonomia,” and “Skin or mucosal involvement.” The global Amylo-AFFECT-QOL and MLHF scores showed significant positive correlations (rs = 0.72, p < 0.05). Patients with a final diagnosis of CA had a global Amylo-AFFECT-QOL score significantly higher than the control group composed by patients with other diagnoses (22.2 ± 13.6 vs. 16.2 ± 13.8, respectively, p-value < 0.01). According to the Amylo-AFFECT-QOL global results, ATTRv patients’ QoL was more affected than AL patients’ QoL or ATTRwt patients’ QoL. Patients with a higher HR-QoL score had a greater risk of death or heart transplant after 1 year of follow-up (log-rank < 0.01).

Conclusion

Amylo-AFFECT-QOL demonstrates good psychometric properties and is useful for quantifying HR-QoL and estimating CA prognosis. Its use may help to improve overall management of patients with CA.

Implications of Extra-cardiac Disease in Patient Selection for Heart Transplantation: Considerations in Cardiac Amyloidosis

Disease-modifying therapies in both light chain and transthyretin amyloidosis have improved patient functional status and survival. Conceivably, as heart failure may progress despite amyloid therapies, more patients may be considered for heart transplantation. In earlier eras, extra-cardiac amyloid deposits significantly reduced post-heart transplant patient survival and functional status compared to the non-amyloid population. In the modern era, transplant centres have reported improved outcomes in amyloidosis as patient selection has grown more stringent. Importantly, systematic candidate evaluation should assess the degree of extra-cardiac involvement, the effectiveness of disease-modifying therapies and downstream effects on patients' nutrition and frailty. This review outlines such an overall approach while also considering that organ-specific selection criteria may vary between individual transplant centres. A methodical approach to patient evaluation will promote better understanding of the prevalence and severity of extra-cardiac disease in amyloidosis patients referred for heart transplantation and of any disparities in decision outcomes in this population.

Pathophysiology, Functional Assessment and Prognostic Implications of Nutritional Disorders in Systemic Amyloidosis

Gastrointestinal involvement is a common clinical feature of patients with systemic amyloidosis. This condition is responsible for invalidating gastrointestinal symptoms, a significant macro and micronutrient deficit, and is a marker of disease severity. Gastrointestinal involvement should be actively sought in patients with systemic amyloidosis, while its diagnosis is challenging in patients with isolated gastrointestinal symptoms. The nutritional status in systemic amyloidosis plays an essential role in the clinical course and is considered a significant prognostic factor. However, the definition of nutritional status is still challenging due to the lack of internationally accepted thresholds for anthropometric and biochemical variables, especially in specific populations such as those with systemic amyloidosis. This review aims to elucidate the fundamental steps for nutritional assessment by using clinical and instrumental tools for better prognostic stratification and patient management regarding quality of life and outcomes.

Care of Patients With Transthyretin Amyloidosis: the Roles of Nutrition, Supplements, Exercise, and Mental Health

Transthyretin (ATTR) amyloidosis is a debilitating disease that results in organ failure and eventual death. As the disease progresses, patients experience neurologic, gastrointestinal, and cardiovascular symptoms that increasingly compromise their nutritional status and exercise capacity. These symptoms cause considerable emotional stress and mental health challenges for patients and caregivers. This review summarizes common symptoms and mechanisms associated with malnutrition and exercise intolerance, and sources of emotional stress, and offers therapeutic strategies to address these issues. Although earlier diagnosis and disease-specific treatment are central to caring for patients with ATTR amyloidosis, additional attention to symptom-focused treatments to improve nutritional status, maintain exercise tolerance and capacity, and improve and maintain mental health are also important. In conclusion, a team-based approach involving multiple clinicians and providers can offer more comprehensive and coordinated care, support, and education for patients and caregivers.

Counseling Family Members and Monitoring for Evidence of Disease in Asymptomatic Carriers of Amyloid Transthyretin Cardiac Amyloidosis

Transthyretin (TTR), a plasma transport protein produced in the liver, is prone to misfolding, leading to the deposition of amyloid fibrils and progressive dysfunction of cardiac and nervous system tissues, a condition known as amyloid TTR (ATTR) amyloidosis. More than 140 different pathogenic variants in TTR have been documented, most of which cause hereditary forms of ATTR amyloidosis. The most common mutations, traditionally known as Val30Met, Val122Ile, and Thr60Ala, lead to predominantly sensory, motor, and autonomic neuropathies, cardiomyopathy, and mixed presentations, respectively, although each mutation may cause symptoms across the neurologic and cardiac spectrum. Val30Met is endemic to Brazil, Japan, Portugal, and Sweden. The Val122Ile variant is present in 3.4% of people with West African ancestry, whereas Thr60Ala originated in northwestern Ireland and spread to the rest of the United Kingdom, the United States, and elsewhere. Val30Met and Thr60Ala tend to have more aggressive clinical presentations at younger ages, whereas Val122Ile predominantly affects older Black men. Due to similarities with hypertrophic cardiomyopathy, heart failure with preserved ejection fraction, and other overlapping conditions, ATTR cardiomyopathy is often under recognized and underdiagnosed, especially in Val122Ile carriers. Understanding these carrier populations and differences in ATTR amyloidosis characteristics associated with each variant is essential for appropriate diagnosis and genetic counseling of affected patients and their relatives.

Characteristics of patients with autonomic dysfunction in the Transthyretin Amyloidosis Outcomes Survey (THAOS)

BACKGROUND

Autonomic dysfunction is common in transthyretin amyloidosis (ATTR amyloidosis), but its frequency, characteristics, and quality-of-life (QoL) impact are not well understood.

METHODS

The Transthyretin Amyloidosis Outcomes Survey (THAOS) is an ongoing, global, longitudinal survey of patients with ATTR amyloidosis, including patients with inherited (ATTRv) and wild-type (ATTRwt) disease and asymptomatic patients with TTR mutations (ClinicalTrials.gov: NCT00628745). In a descriptive analysis, characteristics and Norfolk QoL-DN total (TQoL) scores at enrolment were compared in patients with vs without autonomic dysfunction (analysis cut-off: 1 August 2020).

RESULTS

Autonomic dysfunction occurred in 1181/2922 (40.4%) symptomatic patients, and more commonly in ATTRv (1107/1181 [93.7%]) than ATTRwt (74/1181 [6.3%]) amyloidosis. Time (mean [SD]) from ATTR amyloidosis symptom onset to first autonomic dysfunction symptom was shorter in ATTRv (3.4 [5.7] years) than ATTRwt disease (9.7 [10.4]). In ATTRv disease, patients with vs without autonomic dysfunction had worse QoL (TQoL, 47.3 [33.2] vs 16.1 [18.1]); in ATTRwt disease, those with vs without autonomic dysfunction had similar QoL (23.0 [18.2] vs 19.9 [20.5]).

CONCLUSIONS

Autonomic dysfunction was more common and presented earlier in symptomatic ATTRv than ATTRwt amyloidosis and adversely affected QoL in ATTRv disease. These THAOS findings may aid clinicians in diagnosing and treating patients with ATTR amyloidosis. Trial registration: ClinicalTrials.gov: NCT00628745.

Long-term efficacy and safety of inotersen for hereditary transthyretin amyloidosis: NEURO-TTR open-label extension 3-year update

Background

Hereditary transthyretin amyloidosis (hATTR/ATTRv) results from the deposition of misfolded transthyretin (TTR) throughout the body, including peripheral nerves. Inotersen, an antisense oligonucleotide inhibitor of hepatic TTR production, demonstrated a favorable efficacy and safety profile in patients with the polyneuropathy associated with hATTR in the NEURO-TTR (NCT01737398) study. We report longer-term efficacy and safety data for inotersen, with a median treatment exposure of 3 years.

Methods

Patients who satisfactorily completed NEURO-TTR were enrolled in its open-label extension (OLE) study. Efficacy assessments included the modified Neuropathy Impairment Score + 7 (mNIS + 7), Norfolk Quality of Life–Diabetic Neuropathy (Norfolk QoL-DN) questionnaire total score, and the Short Form 36 (SF-36v2) Health Survey Physical Component Summary score. Safety and tolerability were also assessed. Efficacy is reported for patients living in Europe and North America (this cohort completed the study approximately 9 months before the remaining group of patients outside these regions); safety is reported for the full safety dataset, comprising patients living in Europe, North America, and Latin America/Australasia. This study is registered with ClinicalTrials.gov, identifier NCT02175004.

Results

In the Europe and North America cohort of the NEURO-TTR study, 113/141 patients (80.1%) completed the study, and 109 patients participated in the OLE study. A total of 70 patients continued to receive inotersen (inotersen–inotersen) and 39 switched from placebo to inotersen (placebo–inotersen). The placebo–inotersen group demonstrated sustained improvement in neurological disease progression as measured by mNIS + 7, compared with predicted worsening based on projection of the NEURO-TTR placebo data (estimated natural history). The inotersen–inotersen group demonstrated sustained benefit, as measured by mNIS + 7, Norfolk QoL-DN, and SF-36v2, compared with estimated natural history as well as compared with the placebo–inotersen group. With a maximum exposure of 6.2 years, inotersen was not associated with any additional safety concerns or increased toxicity in the OLE study. Platelet and renal monitoring were effective in reducing the risk of severe adverse events in the OLE study.

Conclusion

Inotersen treatment for > 3 years slowed progression of the polyneuropathy associated with hATTR, and no new safety signals were observed.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-022-11276-8.

Patisiran treatment in patients with hereditary transthyretin-mediated amyloidosis with polyneuropathy after liver transplantation

Hereditary transthyretin-mediated (hATTR) amyloidosis, or ATTRv amyloidosis, is a progressive disease, for which liver transplantation (LT) has been a long-standing treatment. However, disease progression continues post-LT. This Phase 3b, open-label trial evaluated efficacy and safety of patisiran in patients with ATTRv amyloidosis with polyneuropathy progression post-LT. Primary endpoint was median transthyretin (TTR) reduction from baseline. Twenty-three patients received patisiran for 12 months alongside immunosuppression regimens. Patisiran elicited a rapid, sustained TTR reduction (median reduction [Months 6 and 12 average], 91.0%; 95% CI: 86.1%-92.3%); improved neuropathy, quality of life, and autonomic symptoms from baseline to Month 12 (mean change [SEM], Neuropathy Impairment Score, -3.7 [2.7]; Norfolk Quality of Life-Diabetic Neuropathy questionnaire, -6.5 [4.9]; least-squares mean [SEM], Composite Autonomic Symptom Score-31, -5.0 [2.6]); and stabilized disability (Rasch-built Overall Disability Scale) and nutritional status (modified body mass index). Adverse events were mild or moderate; five patients experienced ≥1 serious adverse event. Most patients had normal liver function tests. One patient experienced transplant rejection consistent with inadequate immunosuppression, remained on patisiran, and completed the study. In conclusion, patisiran reduced serum TTR, was well tolerated, and improved or stabilized key disease impairment measures in patients with ATTRv amyloidosis with polyneuropathy progression post-LT (www.clinicaltrials.gov NCT03862807).

The integration of genetically-regulated transcriptomics and electronic health records highlights a pattern of medical outcomes related to increased hepatic transthyretin expression

Transthyretin (TTR) is the precursor of the fibrils that compromise organ function in hereditary and sporadic systemic amyloidoses (ATTR). RNA-interference and anti-sense therapeutics targeting TTR hepatic transcription have been shown to reduce TTR amyloid formation. In the present study, we leveraged genetic and phenotypic information from the UK Biobank and transcriptomic profiles from the Genotype-Tissue Expression project to test the association of genetically regulated TTR gene expression with 7149 traits assessed in 420,531 individuals. We conducted a multi-tissue analysis of TTR transcription and identified an association with a operational procedure related to bone fracture (p = 5.46×10^-6). Using tissue-specific TTR expression information, we demonstrated that the association is driven by the genetic regulation of TTR hepatic expression (odds ratio [OR] = 3.46, p = 9.51×10^-5). Using the UK Biobank electronic health records (EHRs), we investigated the comorbidities affecting individuals undergoing this surgical procedure. Excluding bone fracture EHRs, we identified a pattern of health outcomes previously associated with ATTR manifestations. These included osteoarthritis (OR = 3.18, p = 9.18×10^-8), carpal tunnel syndrome (OR = 2.15, p = .002), and a history of gastrointestinal diseases (OR = 2.01, p = 8.07×10^-4). In conclusion, our study supports that TTR hepatic expression can affect health outcomes linked to physiological and pathological processes presumably related to the encoded protein.

Modified Body Mass Index as a Novel Nutritional and Prognostic Marker in Patients with Cardiac Amyloidosis

The nutritional assessment is gaining clinical relevance since cardiac cachexia and malnutrition are emerging as novel markers of functional status and prognosis in many cardiovascular disorders, including cardiac amyloidosis (CA). This study aimed to evaluate the prognostic role of different nutritional indices for cardiovascular mortality in patients with CA and subgroups. Fifty CA patients (26 AL and 24 ATTR wild-type) were retrospectively analyzed. All patients underwent a comprehensive clinical and laboratory evaluation. Conventional body mass index (cBMI), modified BMI (mBMI), new BMI (nBMI) and prognostic nutritional index (PNI) were analyzed. Multivariate regression analysis was performed to identify the association between nutritional and other clinical-laboratory parameters with cardiovascular death. Compared to ATTRwt patients, those with AL showed lower mBMI values. No significant difference was observed for the other nutritional indices. During a median follow-up of 11.2 months, a lower mBMI quartile was associated with worse survival, in both groups. In multivariate analysis, mBMI emerged as an independent predictor for cardiovascular death. This study showed that mBMI is a novel index of malnutrition and an independent risk factor for cardiovascular mortality in patients with CA in both AL and ATTRwt form.

Evaluation and Management Strategies for GI Involvement with Amyloidosis

Amyloidosis is a heterogeneous disease that can cause a wide array of nonspecific symptoms when the gastrointestinal (GI) tract is involved, including weight loss, early satiety, change in bowel habits with diarrhea, constipation, or alternating bowel pattern. Endoscopy with biopsy for Congo red staining establishes the diagnosis and fibril subtyping helps to guide targeted treatment options. Light chain amyloidosis is the most frequent subtype found throughout the GI tract. Transthyretin amyloidosis is most likely to be found on rectal biopsy. Management of the symptoms of GI tract involvement with amyloidosis relate to addressing the underlying symptom complex that is produced and generally abstracted from the management of severe forms of functional GI disorders. Attention to improving symptom management and nutrition status can improve quality of life in these patients.

Isolated amyloidosis of the gastro-intestinal tract

Amyloidosis is a very rare condition, which, due to its rarity, is often missed or diagnosed in an advanced stage of the disease, causing significant morbidity and mortality. In this review we describe the existing types of amyloidosis focusing on the gastro-intestinal tract. Amyloidosis occurs when abnormal protein fibrils (amyloid) deposit in the muscularis mucosae. This can cause an array of symptoms ranging from (in order of occurrence): gastro-intestinal bleeding, heartburn, unintentional weight loss, early satiety, constipation, diarrhea, nausea, vomiting and fecal incontinence (1). Treatment is focused on the underlying condition (if any) causing the production and deposition of the abnormal fibrils, in combination of symptomatic treatment.

Intra-abdominal bleeding caused by amyloid transthyretin amyloidosis in the gastrointestinal tract: a case report

Diagnosis of gastrointestinal (GI) amyloidosis is often very difficult because of its nonspecific symptoms. However, a few reports have indicated that serious symptoms such as fatal GI bleeding and obstruction or perforation sometimes lead to a diagnosis of GI amyloidosis. A 79-year-old man was transported to our emergency department with a 1-week history of worsening abdominal pain. Abdominal contrast-enhanced computed tomography showed extravasation from part of the transverse colon wall and moderate ascites. Because intra-abdominal bleeding was suspected, the patient urgently underwent partial resection of the transverse colon, which was the source of the bleeding. Postoperative pathological examination of the tissue specimens led to a diagnosis of amyloid transthyretin amyloidosis. This is the first reported case in which intra-abdominal bleeding led to a diagnosis of GI amyloidosis. We should consider the possibility of GI amyloidosis when intraperitoneal bleeding is observed in elderly patients.

Hereditary transthyretin-mediated amyloidosis with polyneuropathy: baseline anthropometric, demographic and disease characteristics of patients from a reference center

BACKGROUND

Hereditary transthyretin-mediated (hATTR) amyloidosis with polyneuropathy is a rare, inherited, multisystem, and often fatal disease caused by a variant in transthyretin (TTR) gene. Baseline characteristics of patients, especially anthropometric data, are scarce in the literature, and they are relevant to define effective treatment strategies.

OBJECTIVE

This study aimed to describe baseline demographic, anthropometric, and disease characteristics in a cohort of patients from a reference center in Brazil.

METHODS

Symptomatic patients not previously included in clinical trials and eligible for treatment were enrolled. Ethnicity, state of residence, age, sex, weight, height, body mass index (BMI), TTR variant, and Polyneuropathy Disability Score (PND) at diagnosis were analyzed.

RESULTS

Among the 108 patients enrolled, 58.33% were male, 60.19% were Caucasian, and 83.33% lived in the Southeast region. Mean age was 51.61 (±16.37) years, mean weight was 65.76 (±15.16) kg, mean height was 168.33 (±10.26) cm, and mean BMI was 23.11 (±4.45) kg/m2. The most prevalent variant was V30M (86.11%). Patients with PND score 0 presenting autonomic neuropathy were 14.81%. Patients with PND score I-II and III-IV were 52.78 and 32.41%, respectively. Mean weight and BMI were significantly lower in patients with sensory-motor manifestations.

CONCLUSIONS

This is the largest cohort of patients in Brazil for whom anthropometric characteristics have been described. Baseline demographic, anthropometric, and disease data indicate that delay in diagnosis of hATTR amyloidosis with polyneuropathy is still a problem and that efforts must be made to expedite diagnosis and maximize opportunities for new disease-modifying treatments.

Current and Emerging Therapies for Hereditary Transthyretin Amyloidosis: Strides Towards a Brighter Future

The past few years have witnessed an unprecedented acceleration in the clinical development of novel therapeutic options for hereditary transthyretin amyloidosis. Recently approved agents and drugs currently under investigation not only represent a major breakthrough in this field but also provide validation of the therapeutic potential of innovative approaches, like RNA interference and CRISPR-Cas9-mediated gene editing, in rare inherited disorders. In this review, we describe the evolving therapeutic landscape for hereditary transthyretin amyloidosis and discuss how this highly disabling and fatal condition is turning into a treatable disease. We also provide an overview of the molecular mechanisms involved in transthyretin (TTR) amyloid formation and regression, to highlight how a deeper understanding of these processes has contributed to the identification of novel treatment targets. Finally, we focus on major areas of uncertainty and unmet needs that deserve further efforts to improve long-term patients' outcomes and allow for a brighter future.

Temporal Trends of Wild-Type Transthyretin Amyloid Cardiomyopathy in the Transthyretin Amyloidosis Outcomes Survey

BACKGROUND

Transthyretin amyloid cardiomyopathy results from the accumulation of wild-type (ATTRwt) or variant (ATTRv) transthyretin amyloid fibrils in the myocardium. THAOS (Transthyretin Amyloidosis Outcomes Survey) is a global, longitudinal, observational survey of patients with ATTRv and ATTRwt amyloidosis and asymptomatic patients with transthyretin mutations.

OBJECTIVES

This study explored temporal trends in ATTRwt amyloidosis diagnoses using data from THAOS.

METHODS

Using THAOS data from December 2007 to January 2020, the following comparisons were made according to year: ATTRwt amyloidosis diagnoses in the United States versus rest of the world, ATTRwt versus ATTRv amyloidosis with cardiac-associated mutations diagnoses, and ATTRwt amyloidosis diagnoses by tissue biopsy versus bone scintigraphy.

RESULTS

There were 1,069 patients with ATTRwt amyloidosis and 525 with ATTRv amyloidosis with cardiac mutations enrolled in THAOS. The median time from symptom onset to ATTRwt amyloidosis diagnosis did not change over the past 5 years (>60 months from 2015-2019). ATTRwt amyloidosis diagnoses increased from 2 in 2005 to >100 per year from 2016, with a more pronounced increase in the United States compared with the rest of the world. Diagnoses of ATTRwt amyloidosis by tissue biopsy increased yearly and peaked in 2014 before declining, whereas diagnoses by bone scintigraphy increased markedly since 2011. ATTRv amyloidosis with cardiac mutation diagnoses increased from 3 in 2005 to 37 in 2011, then plateaued. The proportion of patients with ATTRwt amyloidosis diagnosed with New York Heart Association functional class III/IV heart failure decreased from 2012 (46.4%) to 2019 (16.0%).

CONCLUSIONS

In the past decade, ATTRwt amyloidosis diagnoses increased worldwide. Despite the growing utilization of bone scintigraphy, patients are diagnosed several years after symptom onset. (Transthyretin Amyloidosis Outcomes Survey [THAOS]; NCT00628745).

Screening for hereditary transthyretin amyloidosis in Bulgaria

Transthyretin amyloid (ATTR) amyloidosis is a rare disorder with an adult-onset defined by the accumulation of misfolded fibrils predominantly in peripheral nerves, the heart, and the digestive tract. The disease is characterized by two forms - hereditary (ATTRv) or acquired (ATTRwt). Various point mutations in the transthyretin gene induce the hereditary form of the disease. For finding new cases of ATTR amyloidosis and proper screening, the establishment of a multidisciplinary team and a Centre of Excellence (CoE) is essential. CoE provides regular education and training for better diagnosis and treatment. In the current review, we focus on the importance of having a multidisciplinary team and CoE, the screening strategy for ATTR amyloidosis in Bulgaria, and assessments performed when a patient is first suspected of having this rare disease.

ATTR amyloidosis during the COVID-19 pandemic: insights from a global medical roundtable

BACKGROUND

The global spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causing the ongoing coronavirus disease 2019 (COVID-19) pandemic has raised serious concern for patients with chronic disease. A correlation has been identified between the severity of COVID-19 and a patient's preexisting comorbidities. Although COVID-19 primarily involves the respiratory system, dysfunction in multiple organ systems is common, particularly in the cardiovascular, gastrointestinal, immune, renal, and nervous systems. Patients with amyloid transthyretin (ATTR) amyloidosis represent a population particularly vulnerable to COVID-19 morbidity due to the multisystem nature of ATTR amyloidosis.

MAIN BODY

ATTR amyloidosis is a clinically heterogeneous progressive disease, resulting from the accumulation of amyloid fibrils in various organs and tissues. Amyloid deposition causes multisystem clinical manifestations, including cardiomyopathy and polyneuropathy, along with gastrointestinal symptoms and renal dysfunction. Given the potential for exacerbation of organ dysfunction, physicians note possible unique challenges in the management of patients with ATTR amyloidosis who develop multiorgan complications from COVID-19. While the interplay between COVID-19 and ATTR amyloidosis is still being evaluated, physicians should consider that the heightened susceptibility of patients with ATTR amyloidosis to multiorgan complications might increase their risk for poor outcomes with COVID-19.

CONCLUSION

Patients with ATTR amyloidosis are suspected to have a higher risk of morbidity and mortality due to age and underlying ATTR amyloidosis-related organ dysfunction. While further research is needed to characterize this risk and management implications, ATTR amyloidosis patients might require specialized management if they develop COVID-19. The risks of delaying diagnosis or interrupting treatment for patients with ATTR amyloidosis should be balanced with the risk of exposure in the health care setting. Both physicians and patients must adapt to a new construct for care during and possibly after the pandemic to ensure optimal health for patients with ATTR amyloidosis, minimizing treatment interruptions.

Recommendations for the diagnosis and management of transthyretin amyloidosis with gastrointestinal manifestations

Transthyretin amyloid (ATTR) amyloidosis is an adult-onset, rare systemic disorder characterized by the accumulation of misfolded fibrils in the body, including the peripheral nerves, the heart and the gastrointestinal tract. Gastrointestinal manifestations are common in hereditary (ATTRv) amyloidosis and are present even before the onset of the polyneuropathy in some cases. Delays in diagnosis of ATTRv amyloidosis with gastrointestinal manifestations commonly occur because of fragmented knowledge among gastroenterologists and general practitioners, as well as a shortage of centers of excellence and specialists dedicated to disease management. Although the disease is becoming well-recognized in the societies of Neurology and Cardiology, it is still unknown for most gastroenterologists. This review presents the recommendations for ATTRv amyloidosis with gastrointestinal manifestations elaborated by a working group of European gastroenterologists and neurologists, and aims to provide digestive health specialists with an overview of crucial aspects of ATTRv amyloidosis diagnosis to help facilitate rapid and accurate identification of the disease by focusing on disease presentation, misdiagnosis and management of gastrointestinal symptoms.

Screening for ATTR amyloidosis in the clinic: overlapping disorders, misdiagnosis, and multiorgan awareness

Amyloid transthyretin (ATTR) amyloidosis is a clinically heterogeneous and fatal disease that results from deposition of insoluble amyloid fibrils in various organs and tissues, causing progressive loss of function. The objective of this review is to increase awareness and diagnosis of ATTR amyloidosis by improving recognition of its overlapping conditions, misdiagnosis, and multiorgan presentation. Cardiac manifestations include heart failure, atrial fibrillation, intolerance to previously prescribed antihypertensives, sinus node dysfunction, and atrioventricular block, resulting in the need for permanent pacing. Neurologic manifestations include progressive sensorimotor neuropathy (e.g., pain, weakness) and autonomic dysfunction (e.g., erectile dysfunction, chronic diarrhea, orthostatic hypotension). Non-cardiac red flags often precede the diagnosis of ATTR amyloidosis and include musculoskeletal manifestations (e.g., carpal tunnel syndrome, lumbar spinal stenosis, spontaneous rupture of the distal tendon biceps, shoulder and knee surgery). Awareness and recognition of the constellation of symptoms, including cardiac, neurologic, and musculoskeletal manifestations, will help with early diagnosis of ATTR amyloidosis and faster access to therapies, thereby slowing the progression of this debilitating disease.

Diagnosis and treatment of transthyretin-related amyloidosis cardiomyopathy

Transthyretin-related amyloidosis (ATTR) is a subgroup of amyloidosis that results from extracellular misassembled and toxic amyloid deposits affecting multiple organ systems, and cardiac tissues in particular. Because ATTR often presents as heart failure with preserved ejection fraction (HFpEF), it has been largely underdiagnosed. Once considered incurable with a grave prognosis, ATTR cardiomyopathy has seen the development of promising alternatives for diagnosis and treatment, with early diagnosis and treatment of ATTR cardiomyopathy highly beneficial due to its high mortality rate. For instance, diagnosing ATTR cardiomyopathy previously required a cardiac biopsy, but new modalities, such as cardiac magnetic resonance imaging and radionuclide bone scans, show promise in accurately diagnosing ATTR cardiomyopathy. Ongoing research and clinical trials have focused on identifying new treatments which primarily target amyloid fiber formation by inhibiting TTR gene expression, stabilizing the TTR tetramer, preventing oligomer aggregation, or affecting degradation of amyloid fibers. In this review, we describe the advances made in the diagnosis and treatment of ATTR in order to increase awareness of the disease and encourage a lower threshold for ATTR workup. Our review also highlights the need for improving the screening, diagnosis, and treatment guidelines for ATTR cardiomyopathy.

Avoiding misdiagnosis: expert consensus recommendations for the suspicion and diagnosis of transthyretin amyloidosis for the general practitioner

BACKGROUND

Transthyretin amyloidosis (also known as ATTR amyloidosis) is a systemic, life-threatening disease characterized by transthyretin (TTR) fibril deposition in organs and tissue. A definitive diagnosis of ATTR amyloidosis is often a challenge, in large part because of its heterogeneous presentation. Although ATTR amyloidosis was previously considered untreatable, disease-modifying therapies for the treatment of this disease have recently become available. This article aims to raise awareness of the initial symptoms of ATTR amyloidosis among general practitioners to facilitate identification of a patient with suspicious signs and symptoms.

METHODS

These consensus recommendations for the suspicion and diagnosis of ATTR amyloidosis were developed through a series of development and review cycles by an international working group comprising key amyloidosis specialists. This working group met to discuss the barriers to early and accurate diagnosis of ATTR amyloidosis and develop a consensus recommendation through a thorough search of the literature performed using PubMed Central.

RESULTS

The cardiac and peripheral nervous systems are most frequently involved in ATTR amyloidosis; however, many patients often also experience gastrointestinal and other systemic manifestations. Given the multisystemic nature of symptoms, ATTR amyloidosis is often misdiagnosed as a more common disorder, leading to significant delays in the initiation of treatment. Although histologic evaluation has been the gold standard to confirm ATTR amyloidosis, a range of tools are available that can facilitate early and accurate diagnosis. Of importance, genetic testing should be considered early in the evaluation of a patient with unexplained peripheral neuropathy.

CONCLUSIONS

A diagnostic algorithm based on initial red flag symptoms and manifestations of cardiac or neurologic involvement will facilitate identification by the general practitioner of a patient with clinically suspicious symptoms, enabling subsequent referral of the patient to a multidisciplinary specialized medical center.

Quality of life outcomes in APOLLO, the phase 3 trial of the RNAi therapeutic patisiran in patients with hereditary transthyretin-mediated amyloidosis

Introduction: Hereditary transthyretin-mediated (hATTR) amyloidosis is a rare, fatal, multisystem disease leading to deteriorating quality of life (QOL). The impact of patisiran on QOL in patients with hATTR amyloidosis with polyneuropathy from the phase 3 APOLLO study (NCT01960348) is evaluated.Methods: Patients received either patisiran 0.3 mg/kg (n = 148) or placebo (n = 77) intravenously once every three weeks for 18 months. Multiple measures were used to assess varying aspects of QOL.Results: At 18 months, compared with placebo, patisiran improved Norfolk Quality of Life-Diabetic Neuropathy (Norfolk QOL-DN) score; (least squares [LS] mean difference: -21.1; p = 1.10 × 10^-10; improved across all domains), EuroQoL 5-dimensions 5-levels (LS mean difference: 0.2; p = 1.4 × 10^-12), EuroQoL-visual analog scale (LS mean difference: 9.5; p=.0004), Rasch-built Overall Disability Scale (LS mean difference: 9.0; p = 4.07 × 10^-16) and Composite Autonomic Symptom Score-31(COMPASS-31; LS mean difference: -7.5; p=.0008). Placebo-treated patients experienced rapid QOL deterioration; treatment effects for patisiran were observed as early as 9 months. At 18 months, patisiran improved Norfolk QOL-DN total score and three individual domains as well as COMPASS-31 total scores relative to baseline. Consistent benefits were also observed in the cardiac subpopulation.Conclusion: The benefits of patisiran across all QOL measures and the rapid deterioration observed with placebo, highlight the urgency in early treatment for patients with hATTR amyloidosis with polyneuropathy.

Amyloidosis in Heart Failure

PURPOSE

Amyloidosis represents an increasingly recognized but still frequently missed cause of heart failure. In the light of many effective therapies for light chain (AL) amyloidosis and promising new treatment options for transthyretin (ATTR) amyloidosis, awareness among caregivers needs to be raised to screen for amyloidosis as an important and potentially treatable differential diagnosis. This review outlines the diversity of cardiac amyloidosis, its relation to heart failure, the diagnostic algorithm, and therapeutic considerations that should be applied depending on the underlying type of amyloidosis.

RECENT FINDINGS

Non-biopsy diagnosis is feasible in ATTR amyloidosis in the absence of a monoclonal component resulting in higher detection rates of cardiac ATTR amyloidosis. Biomarker-guided staging systems have been updated to facilitate risk stratification according to currently available biomarkers independent of regional differences, but have not yet prospectively been tested. Novel therapies for hereditary and wild-type ATTR amyloidosis are increasingly available. The complex treatment options for AL amyloidosis are improving continuously, resulting in better survival and quality of life. Mortality in advanced cardiac amyloidosis remains high, underlining the importance of early diagnosis and treatment initiation. Cardiac amyloidosis is characterized by etiologic and clinical heterogeneity resulting in a frequently delayed diagnosis and an inappropriately high mortality risk. New treatment options for this hitherto partially untreatable condition have become and will become available, but raise challenges regarding their implementation. Referral to specialized centers providing access to extensive and targeted diagnostic investigations and treatment initiation may help to face these challenges.

An unusual case of hereditary transthyretin-related amyloidosis and ulcerative colitis in a young Indian girl

Hereditary transthyretin (TTR) amyloidosis is a multisystem disorder caused by extracellular amyloid deposition, usually presenting with neurological and cardiovascular involvement. Gastrointestinal involvement, if present, is usually in the form of motility symptoms like diarrhea, constipation, or diarrhea alternating with constipation. Presentations mimicking ulcerative colitis without other system involvement are rare. Here we present a case of a young female from northern India, who presented with blood‐admixed diarrhea without any feature of any other system involvement. She was diagnosed and treated as ulcerative colitis for two years with ambivalent response, although the compliance to therapy was also poor. She was re‐evaluated when she presented with recurrence of symptoms and new onset dysphagia. On evaluation, she was diagnosed as hereditary transthyrtetin related amyloidosis.

Fecal calprotectin levels are elevated in transthyretin amyloidosis patients with gastrointestinal manifestations

Transthyretin amyloid (ATTR) amyloidosis is a rare systemic disorder characterized by amyloid deposits formed by misfolded monomers of the transthyretin. Gastrointestinal (GI) manifestations are common in ATTR amyloidosis; however, their pathogenesis is not fully elucidated. In the present study, we aim to evaluate the diagnostic role of fecal calprotectin (FC) in ATTR amyloidosis patients with GI manifestations.We recruited 21 consecutive ATTR amyloidosis patients and 42 sex and age-matched healthy controls. The presentation of GI symptoms and the severity of peripheral neuropathy were evaluated. Colonoscopy and FC assessment were performed in all subjects.Mean levels of FC in ATTR amyloidosis patients (184 μg/g [30-430]) were significantly higher thаn those of controls (40 μg/g [30-70]), P < .001. Receiver operating characteristic curve analysis indicated a FC cut-off level of 71 μg/g, which differentiates ATTR amyloidosis with GI manifestations from healthy subjects with 91% sensitivity, 100% specificity, 100% positive predictive value, 95% negative predictive value and 97% overall accuracy. FC values were significantly associated with the presence of neutrophilic granulocytic infiltration in the colonic mucosa (P = .002), with the presence of amyloid deposits in rectal mucosa (P = .007) and the presence of diarrhea (P = .046).FC levels are elevated in patients with ATTR amyloidosis with GI manifestations, which suggests an inflammatory component in the pathogenesis of the disease. The presence of elevated FC concentrations could help gastroenterologists to include ATTR amyloidosis in their diagnostic work-up.

Expert consensus recommendations to improve diagnosis of ATTR amyloidosis with polyneuropathy

Amyloid transthyretin (ATTR) amyloidosis with polyneuropathy (PN) is a progressive, debilitating, systemic disease wherein transthyretin protein misfolds to form amyloid, which is deposited in the endoneurium. ATTR amyloidosis with PN is the most serious hereditary polyneuropathy of adult onset. It arises from a hereditary mutation in the TTR gene and may involve the heart as well as other organs. It is critical to identify and diagnose the disease earlier because treatments are available to help slow the progression of neuropathy. Early diagnosis is complicated, however, because presentation may vary and family history is not always known. Symptoms may be mistakenly attributed to other diseases such as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), idiopathic axonal polyneuropathy, lumbar spinal stenosis, and, more rarely, diabetic neuropathy and AL amyloidosis. In endemic countries (e.g., Portugal, Japan, Sweden, Brazil), ATTR amyloidosis with PN should be suspected in any patient who has length-dependent small-fiber PN with autonomic dysfunction and a family history of ATTR amyloidosis, unexplained weight loss, heart rhythm disorders, vitreous opacities, or renal abnormalities. In nonendemic countries, the disease may present as idiopathic rapidly progressive sensory motor axonal neuropathy or atypical CIDP with any of the above symptoms or with bilateral carpal tunnel syndrome, gait disorders, or cardiac hypertrophy. Diagnosis should include DNA testing, biopsy, and amyloid typing. Patients should be followed up every 6–12 months, depending on the severity of the disease and response to therapy. This review outlines detailed recommendations to improve the diagnosis of ATTR amyloidosis with PN.

Pharyngo-laryngeal involvement in systemic amyloidosis with cardiac involvement: a prospective observational study

Background: Systemic amyloidosis with cardiac involvement (CA) is a severe disease caused by the aggregation of misfolded proteins infiltrating organs and tissues and leading to their dysfunction. No study has yet focused on potential pharyngo-laryngeal impairments associated to CA. Our objective was to define its prevalence and describe pharyngo-laryngeal involvement patterns in a population with CA (light chain: AL, wild-type transthyretin: ATTRwt, variant transthyretin: ATTRv). Methods: Consecutive patients with a confirmed diagnosis of CA were prospectively investigated for pharyngo-laryngeal involvement. This included questionnaires on symptoms of dysphonia/dysphagia and quality of life Voice Handicap Index (VHI). In cases of dysphonia, a nasofibroscopy was performed to evaluate potential laryngeal organic lesions of amyloid infiltration and induced laryngeal dysfunction (mobility, glottic air leak). In cases of dysphagia, Video Endoscopy Swallowing Study (VESS) was performed to evaluate the presence of hypopharyngeal pooling at rest and during swallowing and the time of swallowing 80 ml of water. Results: Ninety-five CA patients were enrolled, of whom 19 were ATTRv, 36 AL and 40 ATTRwt. Their mean age was 73.8 ± 9.2 years and the sex ratio was 2.6 in favor of men. Dysphagia was reported in 17% of the patients and 40% had more specific oropharyngeal symptoms (food sticking, regurgitation, change in dietary habits), preceding the CA diagnosis by 7 (0-24) months. Recent weight loss was reported in 60% of the patients (mean loss of 10 ± 6.3 kg). VESS showed functional swallowing impairment in only 4 patients without any macroscopic organic lesion. Dysphonia was reported in 36% of the patients (44% and 47% in AL and ATTRv sub-groups, respectively) of whom 40% had functional or organic laryngeal abnormality (14% of vocal fold mobility dysfunction and 26% of abnormal mucosa) without any macroscopic-specific lesions of amyloid infiltration in these patients. Conclusions: This prospective study suggests, for the first time, that amyloid associated with CA could infiltrate the various anatomical structures of the pharyngo-larynx, responsible for functional impairment and potential nutritional depletion and poor quality of life.

Analysis of autonomic outcomes in APOLLO, a phase III trial of the RNAi therapeutic patisiran in patients with hereditary transthyretin-mediated amyloidosis

Hereditary transthyretin-mediated (hATTR) amyloidosis is a progressive, debilitating disease often resulting in early-onset, life-impacting autonomic dysfunction. The effect of the RNAi therapeutic, patisiran, on autonomic neuropathy manifestations in patients with hATTR amyloidosis with polyneuropathy in the phase III APOLLO study is reported. Patients received patisiran 0.3 mg/kg intravenously (n = 148) or placebo (n = 77) once every 3 weeks for 18 months. Patisiran halted or reversed polyneuropathy and improved quality of life from baseline in the majority of patients. At baseline, patients in APOLLO had notable autonomic impairment, as demonstrated by the Composite Autonomic Symptom Score-31 (COMPASS-31) questionnaire and Norfolk Quality of Life-Diabetic Neuropathy (Norfolk QOL-DN) questionnaire autonomic neuropathy domain. At 18 months, patisiran improved autonomic neuropathy symptoms compared with placebo [COMPASS-31, least squares (LS) mean difference, − 7.5; 95% CI: − 11.9, − 3.2; Norfolk QOL-DN autonomic neuropathy domain, LS mean difference, − 1.1; − 1.8, − 0.5], nutritional status (modified body mass index, LS mean difference, 115.7; − 82.4, 149.0), and vasomotor function (postural blood pressure, LS mean difference, − 0.3; − 0.5, − 0.1). Patisiran treatment also led to improvement from baseline at 18 months for COMPASS-31 (LS mean change from baseline, − 5.3; 95% CI: − 7.9, − 2.7) and individual domains, orthostatic intolerance (− 4.6; − 6.3, − 2.9) and gastrointestinal symptoms (− 0.8; − 1.5, − 0.2). Rapid worsening of all study measures was observed with placebo, while patisiran treatment resulted in stable or improved scores compared with baseline. Patisiran demonstrates benefit across a range of burdensome autonomic neuropathy manifestations that deteriorate rapidly without early and continued treatment.

Strategies to improve the quality of life in patients with hereditary transthyretin amyloidosis (hATTR) and autonomic neuropathy

Purpose

Hereditary transthyretin amyloidosis (hATTR) is a severe adult-onset progressive disease mainly involving the peripheral nervous system and the heart, with a prominent impact on the autonomic nervous system. This review summarizes the clinical aspects of autonomic dysfunction in hATTR, and their impact on quality of life as well as potential therapeutic options.

Methods

Literature review.

Results

Autonomic dysfunction, causing neurogenic orthostatic hypotension, gastroparesis, constipation, diarrhea, bladder dysfunction, and erectile dysfunction in males, has a major impact on the quality of life of patients with hATTR. Improvement of qualify of life in patients with hATTR implies periodic symptomatic screening and early management, taking into consideration comorbidities and medication side effects. The specific effect of the disease-modifying treatment on this aspect remains to be unraveled.

Conclusions

Management of autonomic dysfunction in patients with hAATR is feasible and can result in improved qualify of life. Novel disease-modifying treatments for hAATR may contribute to improve autonomic dysfunction, although specific studies are required.

Assessment of patients with hereditary transthyretin amyloidosis - understanding the impact of management and disease progression

Timely diagnosis of hereditary variant transthyretin (ATTRv) amyloidosis is critical for appropriate treatment and optimal outcomes. Significant differences are seen between patients receiving treatment and those who are not, though disease progression may continue despite treatment in some patients. Healthcare professionals caring for patients with ATTRv amyloidosis therefore need reliable ongoing assessments to understand the continuing course of disease and make appropriate treatment choices on an individual basis. Various signs and symptoms experienced by patients may be evaluated as indicators of disease progression, though there is currently no validated score that can be used for such ongoing assessment. Recognizing this situation, a group of clinicians highly experienced in ATTR amyloidosis developed an approach to understand and define disease progression in diagnosed and treated patients with ATTRv amyloidosis. The suggested approach is based on the recognition of distinct phenotypes which may usefully inform the particular tools, tests and investigations that are most likely to be appropriate for individual patients. It is aimed at implementing appropriate and ongoing assessment of patients being treated for ATTRv amyloidosis, such that the effectiveness of management can be usefully assessed throughout the course of disease and management can be tailored according to the patient's requirements.

Diagnosis and treatment of gastrointestinal dysfunction in hereditary TTR amyloidosis

PURPOSE

To review the management of gastrointestinal symptoms in patients with hereditary transthyretin amyloidosis, discussing diagnostic evaluations, assessment of disease progression and therapeutic strategies that could be implemented in routine practice.

METHODS

Literature review. Key search terms included "gastrointestinal symptoms", "autonomic neuropathy", "hereditary transthyretin amyloidosis" and "familial amyloid polyneuropathy".

RESULTS

Gastrointestinal disturbances are a common and serious manifestation of hereditary transthyretin amyloidosis, with significant effects on patients' quality of life and demonstrating a strong association with mortality. Gastrointestinal involvement is more often subclinical in the early stages of the disease, although in some patients gastric and/or bowel abnormalities may be the inaugural symptoms. In both cases, under-recognition, delayed investigation and suboptimal treatment frequently occur. A clear understanding of the mechanisms underlying gastrointestinal dysfunction in hereditary transthyretin amyloidosis is still lacking, but similar to diabetic enteropathy, multiple pathophysiological alterations seem to play a role.

CONCLUSIONS

Early detection and treatment of gastrointestinal disturbances is key to the successful treatment of this devastating disease. Gastroenterologists play a valuable role in both the diagnosis and the timely management of gastrointestinal symptoms in hereditary transthyretin amyloidosis and should, therefore, be part of a multidisciplinary and comprehensive approach to this disorder.

Novel RNA-targeted therapies for hereditary ATTR amyloidosis and their impact on the autonomic nervous system

PURPOSE

Transthyretin-mediated hereditary amyloidosis (hATTR amyloidosis) is a multisystemic disease with heterogeneous clinical presentation. Hallmarks of the disease are sensory-motor and autonomic neuropathy and cardiomyopathy. Two disease-modifying drugs, inotersen (an antisense oligonucleotide) and patisiran (a small interfering RNA agent), were recently approved for the treatment of hATTR polyneuropathy. We here review the results of the RNA-targeted therapy clinical trials with special emphasis on the endpoints measuring autonomic symptoms and function.

METHODS

Literature review. We used the terms "autonomic neuropathy", "dysautonomia", "autonomic symptoms", "oligonucleotides", "inotersen" and "patisiran" in patients with hATTR amyloidosis.

RESULTS

In the NEURO-TTR (inotersen) clinical trial, the modified NIS+7 score (mNIS+7) remained stable in 36% of the patients in the inotersen arm (defined as a change of less than 2 points), and 50% of patients had improved quality of life (Norfolk-QOL-DN score) after 15 months. In the APOLLO patisiran trial, 74% of the patients showed stabilization of the neuropathy, defined as a < 10 points increase on mNIS+7, and 51% of patients showed an improvement of quality of life (Norfolk QOL-DN), favoring patisiran at 18 months. Patients on patisiran had a reduced burden of autonomic dysfunction as measured by the COMPASS-31, and a stabilization of nutritional status, suggesting an effect on gastrointestinal autonomic function.

CONCLUSIONS

Clinical trials of inotersen and patisiran showed that these agents were able to halt the progression of the disease, with some patients even reducing the burden of polyneuropathy, and improving qualify of life. The information on their impact on autonomic parameters is limited, warranting further dedicated studies.

Development of measures of polyneuropathy impairment in hATTR amyloidosis: From NIS to mNIS + 7

Hereditary transthyretin-mediated amyloidosis (hATTR amyloidosis) is a rare, life-threatening disease, caused by point mutations in the transthyretin gene. It is a heterogeneous, multisystem disease with rapidly progressing polyneuropathy (including sensory, motor, and autonomic impairments) and cardiac dysfunction. Measures used to assess polyneuropathy in other diseases have been tested as endpoints in hATTR amyloidosis clinical trials (i.e. Neuropathy Impairment Score [NIS], NIS-lower limb, and NIS + 7), yet the unique nature of the polyneuropathy in this disease has necessitated modifications to these scales. In particular, the heterogeneous impairment and the aggressive disease course have been key drivers in developing scales that better capture the disease burden and progression of polyneuropathy in hATTR amyloidosis. The modified NIS + 7 (mNIS + 7) scale was specifically designed to assess polyneuropathy impairment in patients with hATTR amyloidosis, and has been the primary endpoint in two recent, phase III studies in this disease. The mNIS + 7 uses highly standardized, quantitative, and referenced assessments to quantify decreased muscle weakness, muscle stretch reflexes, sensory loss, and autonomic impairment. Physicians using this scale in clinical trials should be specifically trained and monitored to minimize variability. This article discusses the different scales that have been/are being used to assess polyneuropathy in patients with hATTR amyloidosis, their correlation with other disease assessments, and reflects on how and why scales have evolved to the latest iteration of mNIS + 7.

Liver Transplantation for Familial Amyloid Polyneuropathy (Val30Met): Long-Term Follow-up Prospective Study in a Nontransplant Center

BACKGROUND

Familial amyloidosis polyneuropathy (FAP) is a rare, progressive, and life-threatening disease inherited in the autosomal dominant pattern. Liver transplantation is the only proven disease-modifying treatment to date.

AIM

To study the long-term outcomes of patients transplanted for FAP under a multidisciplinary team care.

METHODS

We included adult patients who were transplanted for FAP indication and were followed up in a relevant clinic or admitted in our department.

RESULTS

Twelve patients (6 male) with a mean age of 43 years and mean follow-up post-transplant of 100 months were included. Three patients died in this period, 1 due to a disease-related cause. All patients had peripheral neuropathy (25% severe). Eighty-three percent had autonomic nervous system dysfunction; all men, except one, erectile dysfunction; and half of the patients several genitourinary manifestations. Gastrointestinal involvement was present in 75% of the patients. The severity of several complications related to FAP was found to be associated with waiting on the transplant list for more than 12 months.

CONCLUSIONS

Patients transplanted for FAP have a long survival. Prolonged stay on the transplant waiting list is associated with frequency and severity of disease complications. These patients are best managed in the context of multidisciplinary team care.