Disease-Modifying Therapy for Transthyretin Amyloidosis: Where to Start? Where to Stop?
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ABSTRACT:
SUBMITTER: Fine NM
PROVIDER: S-EPMC8299765 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Transthyretin amyloidoses encompass a variety of acquired and hereditary diseases triggered by systemic extracellular accumulation of toxic transthyretin aggregates and fibrils, particularly in the peripheral nervous system. Since transthyretin amyloidoses are typically complex progressive disorders, therapeutic approaches aiming multiple molecular targets simultaneously, might improve therapy efficacy and treatment outcome. In this study, we evaluate the protective effect of physiologically achievable doses of curcumin on the cytotoxicity induced by transthyretin oligomers in vitro by showing reduction of caspase-3 activity and the levels of endoplasmic reticulum-resident chaperone binding immunoglobulin protein. When given to an aged Familial Amyloidotic Polyneuropathy mouse model, curcumin not only reduced transthyretin aggregates deposition and toxicity in both gastrointestinal tract and dorsal root ganglia but also remodeled congophilic amyloid material in tissues. In addition, curcumin enhanced internalization, intracellular transport and degradation of transthyretin oligomers by primary macrophages from aged Familial Amyloidotic Polyneuropathy transgenic mice, suggesting an impaired activation of naïve phagocytic cells exposed to transthyretin toxic intermediate species. Overall, our results clearly support curcumin or optimized derivatives as promising multi-target disease-modifying agent for late-stage transthyretin amyloidosis.
| S-EPMC4873750 | biostudies-literature
Project description:AimsCardiac transthyretin amyloidosis (ATTR-CM) is a progressive and fatal condition. Prognosis can be determined at diagnosis according to the National Amyloidosis Centre (NAC) transthyretin amyloidosis (ATTR) stage. We sought to examine how NAC ATTR stage changes during follow-up and whether it maintains its prognostic value throughout the disease course.Methods and resultsWe performed a retrospective study of 945 patients with wild-type ATTR-CM (wtATTR-CM) or hereditary ATTR-CM associated with the V122I variant (V122I-hATTR-CM) who were diagnosed and serially evaluated at the UK NAC. Patients who commenced any disease-modifying therapy for amyloidosis were censored at the time of doing so. Landmark Kaplan-Meier survival analyses were performed at diagnosis (n = 945) and at 6 ± 1 (n = 432), 12 ± 3 (n = 562), and 24 ± 3 (n = 316) months and stratified by recalculated NAC ATTR stage at the relevant time point. Cox regression analyses were performed to assess the prognostic significance during follow-up of an increase in NAC ATTR stage from Stage I at diagnosis. Mortality in ATTR-CM was predicted by NAC ATTR stage at each time point [Stage II vs. I, hazard ratios (HRs) 1.95-2.67; P < 0.001; Stage III vs. II, HRs 1.64-2.25; P < 0.001-0.013]. An increase from NAC ATTR Stage I, which occurred in 21%, 32%, and 44% of evaluable patients at 6, 12, and 24 months of follow-up respectively, was highly predictive of ongoing mortality at each time point (HRs 2.58-3.22; P < 0.001) and in each genotypic subgroup (HRs 1.86-4.38; P < 0.05). Increase in NAC ATTR stage occurred earlier in V122I-hATTR-CM than in wtATTR-CM (43% vs. 27% at 12 months of follow-up; P = 0.003).ConclusionsNational Amyloidosis Centre ATTR stage predicts ongoing survival throughout the disease natural history in ATTR-CM, and an increase from NAC ATTR Stage I at diagnosis to a higher NAC ATTR stage predicts mortality throughout follow-up. Serial calculation of NAC ATTR stage suggests a more aggressive phenotype in V122I-hATTR-CM than in wtATTR-CM.
| S-EPMC7755026 | biostudies-literature
Project description:Transthyretin cardiac amyloidosis (ATTR-CA) is an increasingly recognized cause of heart failure (HF) and mortality worldwide. Advances in non-invasive diagnosis, coupled with the development of effective treatments, have shifted ATTR-CA from a rare and untreatable disease to a relatively prevalent condition that clinicians should consider on a daily basis. Amyloid fibril formation results from age-related failure of homoeostatic mechanisms in wild-type ATTR (ATTRwt) amyloidosis (non-hereditary form) or destabilizing mutations in variant ATTR (ATTRv) amyloidosis (hereditary form). Longitudinal large-scale studies in the United States suggest an incidence of cardiac amyloidosis in the contemporary era of 17 per 100 000, which has increased from a previous estimate of 0.5 per 100 000, which was almost certainly due to misdiagnosis and underestimated. The presence and degree of cardiac involvement is the leading cause of mortality both in ATTRwt and ATTRv amyloidosis, and can be identified in up to 15% of patients hospitalized for HF with preserved ejection fraction. Associated features, such as carpal tunnel syndrome, can preceed by several years the development of symptomatic HF and may serve as early disease markers. Echocardiography and cardiac magnetic resonance raise suspicion of disease and might offer markers of treatment response at a myocardial level, such as extracellular volume quantification. Radionuclide scintigraphy with 'bone' tracers coupled with biochemical tests may differentiate ATTR from light chain amyloidosis. Therapies able to slow or halt ATTR-CA progression and increase survival are now available. In this evolving scenario, early disease recognition is paramount to derive the greatest benefit from treatment.
| S-EPMC9897687 | biostudies-literature
Project description:Hereditary amyloidogenic transthyretin (ATTRv) amyloidosis is a rare autosomal dominantly inherited disorder caused by mutations in the transthyretin (TTR) gene. The pathogenetic model of ATTRv amyloidosis indicates that amyloidogenic, usually missense, mutations destabilize the native TTR favouring the dissociation of the tetramer into partially unfolded species that self-assemble into amyloid fibrils. Amyloid deposits and monomer-oligomer toxicity are the basis of multisystemic ATTRv clinical involvement. Peripheral nervous system (autonomic and somatic) and heart are the most affected sites. In the last decades, a better knowledge of pathomechanisms underlying the disease led to develop novel and promising drugs that are rapidly changing the natural history of ATTRv amyloidosis. Thus, clinicians face the challenge of timely diagnosis for addressing patients to appropriate treatment. As well, the progressive nature of ATTRv raises the issue of presymptomatic testing and risk management of carriers. The main aim of this review was to focus on what we know about ATTRv so far, from pathogenesis to clinical manifestations, diagnosis and hence patient's monitoring and treatment, and from presymptomatic testing to management of carriers.
| S-EPMC9780126 | biostudies-literature
Project description:Cardiac amyloidosis is a rare, debilitating, and usually fatal disease increasingly recognized in clinical practice despite patients presenting with non-specific symptoms of cardiomyopathy. The current standard of care (SoC) focuses on preventing further amyloid formation and deposition, either with anti-plasma cell dyscrasia (anti-PCD) therapies in light-chain (AL) amyloidosis or stabilizers of transthyretin (TTR) in transthyretin amyloidosis (ATTR). The SoC is supplemented by therapies to treat the complications arising from organ dysfunction; for example, heart failure, arrhythmia, and proteinuria. Advancements in treatments have improved patient survival, especially for those whose disease is detected and for whom treatment is initiated at an early stage. However, there still are many unmet medical needs, particularly for patients with severe disease for whom morbidity and mortality remain high. There currently are no approved treatments to reverse amyloid infiltration and deplete the amyloid fibrils already deposited in organs, which can continue to cause progressive dysfunction. Anti-fibril therapies aimed at removing the deposited fibrils are being investigated for safety and efficacy in improving outcomes for patients with severe disease. However, there is no clinical evidence yet that removing deposited amyloid fibrils will improve organ function, thereby improving quality of life or extending life. Nevertheless, anti-fibril therapies are actively being investigated in clinical trials to evaluate their ability to complement and synergize with current SoC.
| S-EPMC9808970 | biostudies-literature
Project description:Transthyretin (TTR) amyloidoses comprise a wide spectrum of acquired and hereditary diseases triggered by extracellular deposition of toxic TTR aggregates in various organs. Despite recent advances regarding the elucidation of the molecular mechanisms underlying TTR misfolding and pathogenic self-assembly, there is still no effective therapy for treatment of these fatal disorders. Recently, the "molecular tweezers", CLR01, has been reported to inhibit self-assembly and toxicity of different amyloidogenic proteins in vitro, including TTR, by interfering with hydrophobic and electrostatic interactions known to play an important role in the aggregation process. In addition, CLR01 showed therapeutic effects in animal models of Alzheimer's disease and Parkinson's disease. Here, we assessed the ability of CLR01 to modulate TTR misfolding and aggregation in cell culture and in an animal model. In cell culture assays we found that CLR01 inhibited TTR oligomerization in the conditioned medium and alleviated TTR-induced neurotoxicity by redirecting TTR aggregation into the formation of innocuous assemblies. To determine whether CLR01 was effective in vivo, we tested the compound in mice expressing TTR V30M, a model of familial amyloidotic polyneuropathy, which recapitulates the main pathological features of the human disease. Immunohistochemical and Western blot analyses showed a significant decrease in TTR burden in the gastrointestinal tract and the peripheral nervous system in mice treated with CLR01, with a concomitant reduction in aggregate-induced endoplasmic reticulum stress response, protein oxidation, and apoptosis. Taken together, our preclinical data suggest that CLR01 is a promising lead compound for development of innovative, disease-modifying therapy for TTR amyloidosis.
| S-EPMC3996111 | biostudies-literature
Project description:Transthyretin amyloidosis is a systemic disorder caused by amyloid deposits formed by misfolded transthyretin monomers. Two main forms exist: hereditary and wild-type transthyretin amyloidosis, the former associated with transthyretin gene mutations. There are several disease manifestations; however, gastrointestinal complications are common in the hereditary form. The aim of this study was to explore the prevalence and distribution of gastrointestinal manifestations in transthyretin amyloidosis and to evaluate their impact on the patients' nutritional status and health-related quality of life (HRQoL).The Transthyretin Amyloidosis Outcomes Survey (THAOS) is the first global, multicenter, longitudinal, observational survey that collects data on patients with transthyretin amyloidosis and the registry is sponsored by Pfizer Inc. This study presents baseline data from patients enrolled in THAOS as of June 2013. The modified body mass index (mBMI), in which BMI is multiplied with serum albumin, was used to assess the nutritional status and the EQ-5D Index was used to assess HRQoL.Data from 1579 patients with hereditary transthyretin amyloidosis and 160 patients with wild-type transthyretin amyloidosis were analyzed. Sixty-three percent of those with the hereditary form and 15% of those with the wild-type form reported gastrointestinal symptoms at enrollment. Unintentional weight loss and early satiety were the most frequent symptoms, reported by 32% and 26% of those with transthyretin gene mutations, respectively. Early-onset patients (<50 years) reported gastrointestinal complaints more frequently than those with a late onset (p?<?0.001) and gastrointestinal symptoms were more common in patients with the V30M mutation than in those with other mutations (p?<?0.001). For patients with predominantly cardiac complications, the prevalence of gastrointestinal manifestations was not evidently higher than that expected in the general population. Both upper and lower gastrointestinal symptoms were significant negative predictors of mBMI and the EQ-5D Index Score (p?<?0.001 for all).Gastrointestinal symptoms were common in patients with hereditary transthyretin amyloidosis and had a significant negative impact on their nutritional status and HRQoL. However, patients with wild-type transthyretin amyloidosis or transthyretin mutations associated with predominantly cardiac complications did not show an increased prevalence of gastrointestinal disturbances.
| S-EPMC4005902 | biostudies-other
Project description:IntroductionWild-type transthyretin amyloidosis (ATTRwt amyloidosis) is a progressive disease resulting from the accumulation of wild-type transthyretin (TTR) amyloid fibrils, and is diagnosed primarily in males. This analysis examined sex differences in patients with ATTRwt amyloidosis from the Transthyretin Amyloidosis Outcomes Survey (THAOS).MethodsTHAOS is an ongoing, global, longitudinal, observational survey of patients with transthyretin amyloidosis, including both inherited and wild-type disease, and asymptomatic carriers of TTR mutations. THAOS data were analyzed to identify potential differences in demographic and clinical characteristics between males and females with ATTRwt amyloidosis (data cutoff: August 1, 2021).ResultsOf 1386 patients with ATTRwt amyloidosis, 84 (6%) were female and 1302 (94%) were male. Females had a higher median age at enrollment (80 vs. 78 years; p = 0.002) and symptom onset (75 vs. 73 years; p = 0.045) than males. Mean left ventricular (LV) ejection fraction was higher (53% vs. 48%; p = 0.001) and mean LV diastolic diameter lower (42 vs. 46 mm; p < 0.001) in females versus males, but sex was not identified as a predictor of LV mean wall thickness adjusted for height (beta coefficient - 0.22; p = 0.460) or a predominantly cardiac phenotype (odds ratio 1.60; p = 0.191). Modified polyneuropathy disability scores differed between groups (p < 0.001), with a larger proportion of scores ≥ IIIa among females (23% vs. 7%).ConclusionsFemales with ATTRwt amyloidosis in THAOS tended to present at a later age and showed signs of less severe cardiac impairment and more severe walking impairment.Trial registrationClinicalTrials.gov: NCT00628745.
| S-EPMC9381661 | biostudies-literature
Project description:Transthyretin-related cardiac amyloidosis is a progressive infiltrative cardiomyopathy that mimics hypertensive and hypertrophic heart disease and often goes undiagnosed. In the United States, the hereditary form disproportionately afflicts black Americans, who when compared with whites with wild-type transthyretin amyloidosis, a phenotypically similar condition, present with more advanced disease despite having a noninvasive method for early identification (genetic testing). Although reasons for this are unclear, this begs to consider the inadequate access to care, societal factors, or a biological basis. In an effort to improve awareness and explore unique characteristics, we review the pathophysiology, epidemiology, and therapeutic strategies for transthyretin amyloidosis and highlight diagnostic pitfalls and clinical pearls for identifying patients with amyloid heart disease.
| S-EPMC4874558 | biostudies-literature
Project description:Wild-type transthyretin cardiac amyloidosis (ATTRwt), formerly called senile cardiac amyloidosis (SCA), is almost exclusively a disorder of older adults. As the population ages, the diagnosis of ATTRwt will increase, making it the most common form of cardiac amyloidosis. An important precondition to reduce underdiagnosis and misdiagnosis is to maintain a high index of suspicion for cardiac amyloidosis. Several clues can be gleaned from the clinical history, physical exam, electrocardiography, and noninvasive imaging techniques. Nuclear scintigraphy agents using 99mTc-phosphate derivatives combined with assessment for monoclonal proteins are eliminating the need for tissue confirmation in ATTR. Morbidity and mortality from ATTRwt cardiac amyloid is high and the emergence of numerous therapies based on a biologic understanding of the pathophysiology of this condition, including drugs to inhibit the synthesis of TTR, stabilize TTR, and degrade or extract amyloid, provides new hope for those afflicted. This review briefly covers the epidemiology, pathophysiology, and clinical manifestations, as well as diagnostic strategies and treatment, of ATTR in older adults.
| S-EPMC5127719 | biostudies-literature