Misfolding of transthyretin in vivo is controlled by the redox environment and macromolecular crowding.

Transthyretin (TTR) amyloidosis is a progressive disorder characterized by peripheral neuropathy, autonomic dysfunction, and cardiomyopathy. The precise mechanism by which TTR misfolds and forms fibrils in vivo remains incompletely understood, posing challenges to the development of effective therapeutics. In this study, we reveal that the recently identified nonnative pathological species of TTR (NNTTR), which is enriched in the plasma of ttr-val30met gene carriers, exhibits strong amyloidogenic properties, making it a promising therapeutic target.

Assessing left atrial dysfunction in cardiac amyloidosis using LA-LV strain slope.

Aims: Transthyretin amyloid cardiomyopathy (ATTR-CM) is an infiltrative disease of the myocardium in which extracellular deposits of amyloid cause progressive cardiac impairment. We aimed to evaluate left atrial (LA) deformation and its association with left ventricular (LV) deformation using LA-LV strain loops in patients with ATTR-CM and patients with LV hypertrophy (LVH). We hypothesized that LA strain in ATTR-CM patients is abnormal and more independent of LV strain, compared to LVH patients.

Enlarged cross-sectional area in peripheral nerves in Swedish patients with hereditary V30M transthyretin amyloidosis.

Introduction: In hereditary transthyretin amyloidosis (ATTRv), two different fibrillar forms causing the amyloid deposition, have been identified, displaying substantially cardiac or neuropathic symptoms. Neuropathic symptoms are more frequent in early-onset patients, whereas late-onset patients, besides cardiac symptoms, seem to develop carpal tunnel syndrome, more often. With ultrasonography (US) of peripheral nerves, it is possible to distinguish structural changes, and enlarged cross-sectional area (CSA).

A multicentric study of the disease risks and first manifestations in hereditary transthyretin amyloidosis (ATTRv): insights for an earlier diagnosis.

Background: In hereditary transthyretin amyloidosis (ATTRv), early manifestation and age at onset (AO) may vary strikingly. We assessed the disease'risk (penetrance), AO and initial features in ATTRv families to gain insights on the early disease presentation.

Methods: Genealogical information, AO and first disease manifestations were collected in ATTRv families, from Sweden, Italy (Sicily), Spain (Mallorca), France, Turkey, Brazil.

The role of native T1 values on the evaluation of cardiac manifestation in Japanese Fabry disease patients.

Aims: T1 mapping in cardiac magnetic resonance imaging enables us to distinguish various myocardial diseases showing left ventricular hypertrophy. Fabry disease is a lysosomal storage disorder causing the accumulation of glycosphingolipids into various organs, including the heart, which can be detected by native T1 values in T1 mapping. However, there is no report for the systematic evaluation of native T1 values in Fabry disease in Japan.

[Hereditary transthyretin amyloidosis - from symptomatic to curative treatment?].

Hereditary transthyretin (ATTRv) amyloidosis is a rare but life-threatening multi-systemic disease with clustering areas in, for example, northern Sweden. Until the 1990s, only symptomatic treatments were available but liver transplantation has, in selected patients, been a good therapeutic option since. The first disease-modifying drug for ATTRv amyloidosis was approved in 2011 and since then, the development of new therapeutic drugs has been rapid and successful.

Hereditary transthyretin amyloidosis in Sweden: Comparisons between a non-endemic and an endemic region.

Introduction: Hereditary transthyretin amyloidosis (ATTRv) is endemic in northern Sweden (Västerbotten). The awareness of ATTRv amyloidosis is lower in Stockholm, a non-endemic region in Sweden. The aim of this study was to compare the possible differences in diagnostic delay, disease phenotypes, treatment and survival between a non-endemic and an endemic region in Sweden.

Amyloid fibril composition type is consistent over time in patients with Val30Met (p.Val50Met) transthyretin amyloidosis.

Background: We have previously shown that transthyretin (TTR) amyloidosis patients have amyloid fibrils of either of two compositions; type A fibrils consisting of large amounts of C-terminal TTR fragments in addition to full-length TTR, or type B fibrils consisting of only full-length TTR. Since type A fibrils are associated with an older age in ATTRVal30Met (p.Val50Met) amyloidosis patients, it has been discussed if the TTR fragments are derived from degradation of the amyloid deposits as the patients are aging.

Endogenous Human Proteins Interfering with Amyloid Formation.

Amyloid formation is a pathological process associated with a wide range of degenerative disorders, including Alzheimer's disease, Parkinson's disease, and diabetes mellitus type 2. During disease progression, abnormal accumulation and deposition of proteinaceous material are accompanied by tissue degradation, inflammation, and dysfunction. Agents that can interfere with the process of amyloid formation or target already formed amyloid assemblies are consequently of therapeutic interest.

Epidemiology of hereditary transthyretin amyloidosis in the northernmost region of Sweden: a retrospective cohort study.

Introduction: Epidemiological data on hereditary transthyretin (ATTRv) amyloidosis from the northernmost region of Sweden (Norrbotten) are sparse.

Methods: We reviewed the medical records of all incident cases of ATTRv amyloidosis in Norrbotten between 2006 and 2018. Official population and mortality statistics were used to estimate incidence rates and standardised mortality ratios (SMRs).

Midodrine improves clinical and economic outcomes in patients with septic shock: a randomized controlled clinical trial.

Background: Prolonged use of intravenous (IV) vasopressors in patients with septic shock can lead to deleterious effects.

Aims: This study assessed the impact of midodrine administration on weaning off IV vasopressors and its economic value.

Methods: It is a prospective randomized controlled study of 60 resuscitated patients with septic shock who demonstrated clinical stability on low-dose IV vasopressors for at least 24 h.

Structural basis for transthyretin amyloid formation in vitreous body of the eye.

Amyloid transthyretin (ATTR) amyloidosis is characterized by the abnormal accumulation of ATTR fibrils in multiple organs. However, the structure of ATTR fibrils from the eye is poorly understood. Here, we used cryo-EM to structurally characterize vitreous body ATTR fibrils.

Metabolomics analysis for diagnosis and biomarker discovery of transthyretin amyloidosis.

Untargeted metabolomics is a well-established technique and a powerful tool to find potential plasma biomarkers for early diagnosing hereditary transthyretin amyloidosis. Hereditary transthyretin amyloidosis (ATTRv) is a disabling and fatal disease with different clinical features such as polyneuropathy, cardiomyopathy, different gastrointestinal symptoms and renal failure. Plasma specimens collected from 27 patients with ATTRv (ATTRV30M), 26 asymptomatic V30M carriers and 26 control individuals were subjected to gas chromatography (GC)- and liquid chromatography (LC)-mass spectrometry (MS)-based metabolomics analysis.

Combining ECG and echocardiography to identify transthyretin cardiac amyloidosis in heart failure.

Aims/background: Transthyretin amyloid (ATTR) amyloidosis cardiomyopathy is an underdiagnosed, causatively treatable cause of heart failure (HF). The aim of this study was to evaluate the efficacy of electrocardiogram (ECG) and echocardiography on patients with increased interventricular septum diameter (IVSd) to identify ATTR cardiac amyloidosis (ATTR-CA) patients.

Methods: We investigated 58 patients with HF and an IVSd > 14 mm.

Mechanisms of Transthyretin Inhibition of IAPP Amyloid Formation.

Amyloid-formation by the islet amyloid polypeptide (IAPP), produced by the β-cells in the human pancreas, has been associated with the development of type II diabetes mellitus (T2DM). The human plasma-protein transthyretin (TTR), a well-known amyloid-inhibiting protein, is interestingly also expressed within the IAPP producing β-cells. In the present study, we have characterized the ability of TTR to interfere with IAPP amyloid-formation, both in terms of its intrinsic stability as well as with regard to the effect of TTR-stabilizing drugs.

Characteristics of the Electrocardiogram in Japanese Fabry Patients Under Long-Term Enzyme Replacement Therapy.

An electrocardiogram (ECG) is an important tool for demonstrating cardiac manifestations in various heart diseases. The present study clarified the characteristics of ECG parameters in Japanese Fabry patients under long-term enzyme replacement therapy (ERT). We analyzed the ECGs of 40 Fabry patients (male, = 17; female, = 23) before and after treatment with ERT.

New data on the genetic profile and penetrance of hereditary Val30Met transthyretin amyloidosis in Sweden.

Introduction: Hereditary transthyretin (ATTRv) amyloidosis is of autosomal dominant transmission, caused by a spectrum of mutations in the transthyretin (TTR) gene. The ATTRV30M (p.Val50Met) is the most frequent substitution in Europe.

Abdominal fat pad biopsies exhibit good diagnostic accuracy in patients with suspected transthyretin amyloidosis.

Background: The diagnostic accuracy of histopathological detection of transthyretin amyloid (ATTR) by Congo red staining of abdominal fat samples has been questioned since low sensitivity has been reported, especially for patients with ATTR cardiomyopathy. However, the outcome of surgically obtained fat pad biopsies has not yet been evaluated. The aim was to evaluate the diagnostic accuracy of skin punch biopsies from abdominal fat in patients with suspected ATTR amyloidosis.

Clinical findings of gadolinium-enhanced cardiac magnetic resonance in Fabry patients.

Background: Fabry disease is one of the causes of left ventricular hypertrophy (LVH) and can be treated with enzyme replacement therapy or pharmacological chaperone therapy. Late gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR) can identify myocardial fibrosis and be used for the stratification in LVH. However, the details of the prevalence and characteristics of LGE in Japanese Fabry patients have not been reported.