Circulating ECM proteins decorin and alpha-L-iduronidase differentiate ATTRwt-CM from ATTRwt-negative HFpEF/HFmrEF.

Aims: Wild-type transthyretin cardiac amyloidosis (ATTRwt-CM) is an under-recognized aetiology of heart failure (HF), necessitating early detection for timely treatment. Our study aimed to differentiate patients with ATTRwt-CM from ATTRwt-negative HFpEF/HFmrEF patients by identifying and validating circulating protein biomarkers. In addition, we measured the same biomarkers in patients with cardiomyopathy due to light chain amyloidosis (AL)-CM to gain disease-specific insights.

[Tc]Tc-hydroxydiphosphonate uptake in soft tissue is associated with amyloid load in subcutaneous abdominal fat tissue and mortality in wild-type transthyretin amyloidosis patients.

Purpose: Bone scintigraphy is key to non-invasively diagnosing wild-type transthyretin (ATTRwt) amyloidosis, and is mainly used to assess cardiac radiotracer uptake. However, extracardiac radiotracer uptake is also observed. We investigated whether intensity of soft tissue radiotracer uptake is associated with amyloid load in subcutaneous abdominal fat tissue and with mortality.

ELISA-4-amyloid: diagnostic accuracy of an ELISA panel for typing the four main types of systemic amyloidosis in subcutaneous abdominal fat tissue samples.

Background: Reliable typing of amyloid is essential. Amyloid extraction from tissue enables immunochemical typing of the precursor protein using an enzyme-linked immunosorbent assay (ELISA).

Objective: To assess the diagnostic accuracy of a panel of ELISAs for typing the four main types (AA, ATTR, AL-kappa and AL-lambda amyloid).

Longitudinal analysis of serum neurofilament light chain levels as marker for neuronal damage in hereditary transthyretin amyloidosis.

Objective: To evaluate serum neurofilament light chain (sNfL) as biomarker of disease onset, progression and treatment effect in hereditary transthyretin (ATTRv) amyloidosis patients and variant (v) carriers.

Methods: sNfL levels were assessed longitudinally in persistently asymptomatic v carriers ( = 12), persistently asymptomatic ATTRv amyloidosis patients (defined as asymptomatic patients but with amyloid detectable in subcutaneous abdominal fat tissue) ( = 8), in v carriers who developed polyneuropathy ( = 7) and in ATTRv amyloidosis patients with polyneuropathy on treatment (TTR-stabiliser ( = 20) or TTR-silencer ( = 18)). Polyneuropathy was confirmed by nerve conduction studies or quantitative sensory testing.

High-Sensitivity Cardiac Troponin T to Exclude Cardiac Involvement in TTR Variant Carriers and ATTRv Amyloidosis Patients.

(1) Background: Individuals carrying a pathogenic transthyretin gene variant () are at high risk for developing hereditary transthyretin (ATTRv) amyloidosis and are routinely screened for the development of cardiomyopathy (ATTRv-CM). This study aims to evaluate whether the cardiac biomarkers N-terminal pro B-type natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (hs-cTnT) can be used to rule out ATTRv-CM. (2) Methods: In this retrospective case-control study, data from 46 ATTRv-CM patients and 101 carriers and ATTRv amyloidosis patients without cardiomyopathy were included.

The Protein Network in Subcutaneous Fat Biopsies from Patients with AL Amyloidosis: More Than Diagnosis?

AL amyloidosis is caused by the misfolding of immunoglobulin light chains leading to an impaired function of tissues and organs in which they accumulate. Due to the paucity of -omics profiles from undissected samples, few studies have addressed amyloid-related damage system wide. To fill this gap, we evaluated proteome changes in the abdominal subcutaneous adipose tissue of patients affected by the AL isotypes and λ.

Amyloid fibril structure from the vascular variant of systemic AA amyloidosis.

Systemic AA amyloidosis is a debilitating protein misfolding disease in humans and animals. In humans, it occurs in two variants that are called 'vascular' and 'glomerular', depending on the main amyloid deposition site in the kidneys. Using cryo electron microscopy, we here show the amyloid fibril structure underlying the vascular disease variant.

Protease resistance of amyloid fibrils implies the proteolytic selection of disease-associated fibril morphologies.

Several studies recently showed that fibrils from patient or animal tissue were structurally different from formed fibrils from the same polypeptide chain. Analysis of serum amyloid A (SAA) and Aβ-derived amyloid fibrils additionally revealed that fibrils were more protease stable than fibrils. These observations gave rise to the proteolytic selection hypothesis that suggested that disease-associated amyloid fibrils were selected inside the body by their ability to resist endogenous clearance mechanisms.

Cardiac Transthyretin-derived Amyloidosis: An Emerging Target in Heart Failure with Preserved Ejection Fraction?

Heart failure with preserved ejection fraction (HFpEF) comprises half of the heart failure population. A specific, but underdiagnosed, cause for HFpEF is transthyretin-derived (ATTR) amyloidosis. This article reviews the clinical characteristics of cardiac ATTR amyloidosis.

Neurofilament light chain, a biomarker for polyneuropathy in systemic amyloidosis.

Objective: To study serum neurofilament light chain (sNfL) in amyloid light chain (AL) amyloidosis patients with and without polyneuropathy (PNP) and to corroborate previous observations that sNfL is increased in hereditary transthyretin-related (ATTRv) amyloidosis patients with PNP.

Methods: sNfL levels were assessed retrospectively in patients with AL amyloidosis with and without PNP (AL/PNP+ and AL/PNP-, respectively), patients with ATTRv amyloidosis and PNP (ATTRv/PNP+), asymptomatic transthyretin ( gene mutation carriers (v carriers) and healthy controls. Healthy controls (HC) were age- and sex-matched to both AL/PNP- (HC/AL) and v carriers (HC/v).

[Hereditary and acquired transthyretin-mediated amyloidosis].

We describe three cases, two 70-year-old males with mainly cardiac symptoms and a 34-year-old male with gastro-intestinal and neurologic symptoms. Each patient was shown to have a distinctive type of transthyretin-mediated amyloidosis (ATTR). ATTR amyloidosis is a life-threatening disease characterised by the extracellular deposition of pathogenic transthyretin (TTR).

A real-life cohort study of immunoglobulin light-chain (AL) amyloidosis patients ineligible for autologous stem cell transplantation due to severe cardiac involvement or advanced disease.

To study the outcome of patients with AL amyloidosis who were ineligible for high dose melphalan (HDM) and autologous stem cell transplantation (ASCT). A real-life retrospective observational cohort study of Dutch patients with AL amyloidosis ineligible for HDM and ASCT was performed at the University Medical Center Groningen from January 2001 until April 2017. Primary outcome measure was overall survival (OS).