Amyloid-Journal of Protein Folding Disorders最新文献

Background: A high incidence of valvular involvement of amyloid in the setting of aortic stenosis (AS) has been reported. Amyloid derived from ApoAI (AApoAI) can form local amyloid deposits in the aortic valve. Although a high prevalence of concomitant severe AS and cardiac transthyretin-type amyloidosis (ATTR) has been reported, the prevalence of valvular involvement by ATTR and AApoAI is unclear.

Methods: Using immunostaining and mass spectrometry, we analysed amyloid proteins in 97 aortic valves removed for valve replacement due to AS at Kyoto Prefectural University of Medicine between 2014 and 2021. Clinical information was also reviewed.

Results: Amyloid deposits were found in 44 cases (45%), of which 30 cases (68%) involved ATTR and 33 cases (75%) AApoAI. Statistical analysis showed significantly lower age and E/e' among amyloid-positive cases compared with amyloid-negative cases and significantly lower brain natriuretic peptide, higher fractional shortening, and higher left ventricular ejection fraction among ATTR-positive cases compared with ATTR-negative cases. Seven recent patients underwent bone scintigraphy and ATTR cardiomyopathy was observed in only one case.

Conclusions: AS symptoms can manifest earlier in patients with amyloid or ATTR deposition in the aortic valve than in patients without such deposition, even though left ventricular function is preserved.

Background: Hereditary transthyretin amyloidosis with polyneuropathy (ATTRv-PN) is a progressive fatal disorder caused by deposition of mutant transthyretin (TTR) amyloids mainly in the nerves and heart. Autonomic dysfunction is a major disabling manifestation, affecting 90% of patients with late-onset ATTRv-PN. The current study aimed to investigate brain functional alterations associated with dysautonomia due to peripheral autonomic nerve degeneration in ATTRv-PN.

Methods: Resting-state functional MRI data were acquired from 43 ATTRv-PN patients predominantly of A97S (p.A117S) genotype, and the functional connectivity of central autonomic regions was assessed.

Results: Compared with age-matched healthy controls, the ATTRv-PN patients exhibited (1) reduced functional connectivity of the central autonomic regions such as hypothalamus, amygdala, anterior insula, and middle cingulate cortex with brain areas of the limbic, frontal, and somatosensory systems, and (2) correlations of reduced functional autonomic connectivity with the severity of autonomic dysfunction especially orthostatic intolerance, decreased heart rate variability, and greater clinical disability.

Conclusions: Our findings provide evidence linking peripheral autonomic dysfunction with altered connectivity in the central autonomic network in ATTRv-PN.

Introduction: Although sudden death (SD) is a recognized complication of cardiac amyloidosis, there is scarce data about its incidence, mechanisms, and predictors. The aim of this study was to describe incidence of SD and to analyze possible risk factors.

Methods: Consecutive patients with ATTR or AL cardiac amyloidosis evaluated at two European centers were identified. SD was defined as unexpected death in clinically stable patients. Cox proportional hazard regression was performed to assess risk factors in univariate analysis. Those statistically significant were then assessed through age-adjusted multivariate analysis.

Results: Analysis included 784 patients, 569 with ATTR amyloidosis (mean age 74.1 ± 12.1 years) and 215 with AL amyloidosis (mean age 64.5 ± 10.8 years). After a median follow-up of 1.9 years, SD rate at 2 years was 1.8% in ATTR. Previous pacemaker implantation (PPM) was associated with increased risk after age-adjusted analysis (HR 4.97; 95%CI: 1.39-17.7; p = 0.01). SD rate in AL amyloidosis patients at 2 years was 8.0% after a median follow-up of 1.2 years. Betablockers and NYHA III-IV were independently associated with an increased risk after age-adjusted multivariate analysis (HR 7.06 95%CI (2.31-21.5) p = 0.001) and (HR 4.56 95%CI (1.51-13.8) p = 0.007) respectively.

Conclusions: SD is more frequent in AL than in ATTR cardiac amyloidosis. SD is associated with different risk factors in both entities.

Background: Transthyretin amyloid cardiomyopathy (ATTR-CM) is an underdiagnosed cause of heart failure (HF).

Methods: This epidemiology study assessed the international prevalence of ATTR-CM among patients aged ≥60 years with a history of HF, left ventricular ejection fraction (LVEF) >40%, an end-diastolic interventricular septum thickness (IVST) ≥12 mm, but without diagnosed amyloidosis, history of LVEF ≤40%, cardiomyopathy of known cause, severe valvular, or coronary heart disease. ATTR-CM was determined using cardiac scintigraphy alongside exclusionary testing for light chain amyloidosis. The study was terminated early due to slow recruitment, without safety concerns.

Results: Overall, 56/315 (18%; 95% CI: 13.7-22.5) patients with evaluable scintigraphy had ATTR-CM, with a numerically higher prevalence in: Europe (24%) vs. other regions (9% Asia; 5% North America); at specialist vs non-specialist centres (26% vs. 11%); in males vs. females (24% vs. 10%); and in older vs. younger patients (e.g. >40% among those ≥85 years). Other risk markers (p<.05) included a history of carpal tunnel syndrome, higher N-terminal pro B-type natriuretic peptide concentration, and higher end-diastolic IVST.

Conclusions: ATTR-CM was diagnosed in 18% (95% CI: 13.7-22.5) of evaluable patients with HF, LVEF >40%, and risk markers for ATTR-CM, but no previous diagnosis of amyloidosis. Recruitment bias may have contributed to regional variability. NCT04424914.

Background: Central nervous system dysfunction is common in longstanding hereditary transthyretin amyloidosis (ATTRv) caused by the V30M (p.V50M) mutation. Neuropathology studies show leptomeningeal amyloid deposition and cerebral amyloid angiopathy (CAA). Brain MRI is widely used in the assessment of Aβ associated CAA but there are no systematic studies with brain MRI in ATTRv amyloidosis.

Methods: we performed 3 T brain MRIs in 16 patients with longstanding (>14 years) ATTRV30M. We additionally retrospectively reviewed 48 brain MRIs from patients followed at our clinic. CNS symptoms and signs were systematically accessed, and MRIs were blindly reviewed for ischaemic and haemorrhagic lesions.

Results: in the prospective cohort, we found white matter hyperintensities in 8/16 patients (50%, Fazekas score> =1). There were no relevant microbleeds, large ischaemic or haemorrhagic lesions or superficial siderosis. In the retrospective cohort, microbleeds were found in 5/48 patients (10,4%), two of which with > =20 microbleeds. White matter hyperintensities were found in 20/48 cases (41.7%). White matter lesions, microbleeds and cortical atrophy were not associated with disease duration.

Conclusions: white matter hyperintensities are common in ATTRV30M, irrespective of disease duration. Haemorrhagic lesions are rare, even in patients with longstanding disease, suggesting the existence of other risk factors.