Amyloid-Journal of Protein Folding Disorders最新文献

Background: The investigational monoclonal antibody PRX004 is designed to specifically target and deplete TTR amyloid. Here, we report on the safety, tolerability, pharmacokinetics, pharmacodynamics and preliminary clinical activity of PRX004 in patients with ATTRv amyloidosis.

Methods: This global, multicentre, phase 1 trial comprised a 3 + 3 dose-escalation phase and a long-term extension (LTE) phase (NCT03336580). In the dose-escalation phase, patients received PRX004 (0.1, 0.3, 1, 3, 10 or 30 mg/kg), administered intravenously every 28 days for 3 months. In the LTE, eligible patients could receive up to 15 additional doses. Patients who received doses of ≥3 mg/kg for ≥9 months were assessed for Global Longitudinal Strain (GLS) and Neuropathy Impairment Score (NIS). The primary objective was to determine the maximum tolerated dose (MTD) of PRX004.

Results: Overall, 21 patients with ATTRv amyloidosis completed the dose-escalation phase; 17 subsequently enrolled in the LTE. The MTD was not reached. PRX004 was well tolerated at all doses, with dose-proportional exposure. GLS and NIS were improved or maintained over 9 months (n = 7).

Conclusions: PRX004 was well tolerated in patients with ATTRv amyloidosis and demonstrated potential clinical activity. A phase 2 randomised controlled trial in ATTR cardiomyopathy is ongoing (NCT05442047).

AA amyloidosis is a prototypic example of systemic amyloidosis: it results from the prolonged overproduction of SAA protein produced in response to chronic inflammation. AA amyloidosis primarily affects the kidneys, liver, spleen, gastrointestinal tract, leading to a variety of symptoms. First, this review examines AA amyloidosis in humans, focusing on pathogenesis, clinical presentation, and diagnosis and then in animals. In fact AA amyloidosis is the only systemic amyloidosis that has been largely documented in a remarkable number of vertebrate species: mammals, birds, and fishes, especially in individuals with comorbidities, chronic stress, or held in captivity. Secondly, here, we summarise independent sets of evidence obtained on different animal species, exploring the possible transmissibility of AA amyloidosis especially in crowded or confined populations. Finally, biochemical and structural data on native SAA and on AA amyloid fibrils from human, murine, and cat ex vivo samples are discussed. The available structural data depict a complex scenario, where SAA can misfold forming highly different amyloid assemblies. This review highlights the complexity of AA amyloidosis, emphasising the need for further research into its spread in the animal kingdom, its structural aspects, and pathogenetic mechanisms to evaluate its impact on human and animal health.

Background: Genotyping and amyloid fibril detection in tissues are generally considered the diagnostic gold standard in transthyretin-related amyloidosis. Patients carry less stable TTR homotetramers prone to dissociation into non-native monomers, which rapidly self-assemble into oligomers and, ultimately, amyloid fibrils. Thus, the initial event of the amyloid cascade produces the smallest transthyretin species: the monomers. This creates engineering opportunities for diagnosis that remain unexplored.

Methods: We hypothesise that molecular sieving represents a promising method for isolating and concentrating trace TTR monomers from the tetramers present in plasma samples. Subsequently, immunodetection can be utilised to distinguish monomeric TTR from other low molecular weight proteins within the adsorbed fraction. A two-step assay was devised (ImmunoSieve assay), combining molecular sieving and immunodetection for sensing monomeric transthyretin. This assay was employed to analyse plasma microsamples from 10 individuals, including 5 pre-symptomatic carriers of TTR-V30M, the most prevalent amyloidosis-associated TTR variant worldwide, and 5 healthy controls.

Results: The ImmunoSieve assay enable sensitive detection of monomeric transthyretin in plasma microsamples. Moreover, the circulating monomeric TTR levels were significantly higher in carriers of amyloidogenic TTR mutation.

Conclusions: Monomeric TTR can function as a biomarker for evaluating disease progression and assessing responses to therapies targeted at stabilising native TTR.

Translational research is key in advancing the diagnosis and therapy of systemic amyloidoses. This paper summarises our presentations at the ISA Workshop on Translation in Systemic Amyloidoses held in Athens on September 25-26, 2023. The critical advances made by the pioneers in the field are reviewed, with particular attention to the discoveries and developments of utmost importance to our understanding of what amyloid is and how the substance affects functions. Examples of translational research regarding the mechanisms of cardiac damage in light chain amyloidosis, the role of biomarkers in improving our understanding of the biology of the disease and patients' management, and the molecular mechanisms involved in the cytotoxicity are described. Advances in basic research continue to open new therapeutic avenues.

Aims: Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive disease that causes heart failure due to amyloid fibril deposition. Tafamidis was approved as the first causal treatment in 2020. We here report on real-world data in patients treated with tafamidis for at least 12 months according to the recently defined European Society for Cardiology (ESC) consensus criteria for disease progression.

Methods and results: Three hundred and eight wildtype and 31 hereditary ATTR-CM patients were prospectively enrolled after first diagnosis of ATTR-CM and initiation of tafamidis 61 mg once daily treatment. After 12 months, significant deterioration in Karnofsky Index, estimated glomerular filtration rate (eGFR), N-terminal brain natriuretic peptide (NT-proBNP), septum thickness and left ventricular ejection fraction (LVEF) could be observed, significant disease progression was only detected in 25 patients (9%) using ESC consensus criteria. Mean survival time was 37 months with no differences between responders and non-responders. NT-proBNP was the only independent predictor for poor therapy response (p = .008).

Conclusions: The majority of patients showed no significant disease progression according to the ESC consensus criteria after 12 months of therapy with tafamidis. However, at 12 months, treatment response based on the ESC consensus criteria was not associated with improved survival. Moreover, higher levels of NT-proBNP at diagnosis of ATTR-CM appears to predict poorer treatment response, confirming that timely initiation of therapy is advantageous.

Background: Hereditary transthyretin-related amyloidosis is an autosomal dominant disorder. Recently, disease-modifying therapies (DMTs) have been developed. For at-risk individuals, genetic analysis aids in the early administration of medical care; however, few studies have evaluated the current status of genetic counselling and management of presymptomatic carriers of amyloidogenic variants.

Methods: We retrospectively evaluated the medical records of 202 consecutive participants.

Results: A total of 103 clients who received genetic counselling for predictive testing were at-risk, and 83 underwent predictive testing. Genetic testing results were positive in 33 patients, 11 of whom had confirmed amyloid deposition and were administered DMTs. For presymptomatic V30M (p.V50M) carriers, 32.0 ± 2.4 years (median ± standard error) was the age when amyloid deposition was first identified (95% confidence interval 27.4-36.6). Serum transthyretin (TTR) levels decreased serially with an estimated slope of -1.2 mg/dL/year.

Conclusions: Our study suggests the clinical utility of management using a combination of predictive testing and monitoring methods. Psychosocial support should be considered with collaboration between geneticists/genetic counsellors and psychologists. For a more optimised protocol for monitoring and designing future interventional trials in presymptomatic carriers, prospective cohort studies are necessary to clarify the natural history, particularly in the early stages of the disease.