Nonspecific symptoms and other diagnostic challenges lead to underdiagnosis of cardiac amyloidosis (CA). Artificial intelligence (AI) could help address these challenges, but a summary of the performance of these tools is lacking. This narrative review of published literature describes the performance of AI tools that use data from ECGs and echocardiography to improve identification of CA and challenges that hinder adoption of these tools. Thirteen studies met inclusion criteria with sample sizes ranging from 50 to 2451 patients. Four studies used ECG data, 8 used echocardiography data, and 1 used both. The CA gold standard was typically defined as a CA diagnosis in an institutional or other database but the requirements for these diagnoses were heterogenous across studies, and many did not distinguish among CA subtypes. AI model development varied considerably, and only 4 studies included external validation. The ability of models to predict CA ranged from 0.71 to 1.00, sensitivity ranged from 16% to 100%, and specificity from 75% to 100%. Only 1 study reported model performance across strata of sex, age, race, and CA type. Persistent challenges to AI adoption include usability, cost, value added, electronic health record/information technology interoperability, patient-related factors, regulation, and privacy and liability. Published studies on AI for improved identification of CA show favorable performance measures but numerous methodologic and other challenges must be addressed before these tools are more widely adopted.

AL-Amyloidosis is a rare systemic disease that can occur in patients with monoclonal gammopathy or multiple myeloma. As multiple organs may be affected by deposition of amyloid fibrils, the clinical presentation varies considerably, and the diagnostic process may be challenging.We report on a 59-year-old female who suffered from gastroesophageal reflux symptoms, nausea, epigastric pain, and meteorism over several years. Repeated upper GI endoscopies including biopsies and CT scans were unremarkable except for unspecific enlargement of mesenterial lymph nodes.A few weeks after a surgical hiatal hernia repair with fundoplication, the patient developed massive distension of the stomach and the proximal duodenum resulting in gastric perforation. Histopathological staining of gastric biopsies and mesenterial lymph nodes using hematoxylin and eosin was unremarkable. Because of endoscopic findings (submucosal hematomas, and ulcerations) and the unexplained severe motility disorder, histopathological staining was performed using Congo red. Extensive amyloid deposits were seen. Further workup confirmed AL amyloidosis caused by monoclonal gammopathy. Specific oncological treatment was started.The rare differential diagnosis of amyloidosis should be taken into account in patients with unexplained motility disorders, unspecific gastrointestinal symptoms, and abdominal lymphadenopathy. In the presented case, delayed diagnosis of AL amyloidosis in the gastrointestinal tract led to severe gastroparesis resulting in gastric perforation. Specific histopathologic staining can confirm the diagnosis.

The diagnosis of systemic amyloidosis is decided through histologic materials from biopsy from different organs. This is a retrospective study from the institutional database of our hospital and consisted of patients to being judged to need skin biopsy for the purpose of diagnosing systemic amyloidosis visiting dermatology between April 2005 and August 2022. A total of 30 patients underwent the skin biopsy of dermis and fatty tissue on abdominal wall without rash and a total of 36 specimens were obtained. A total of 14 of these specimens showed amyloid deposition histologically. Among the 14 specimens, amyloid immunoglobin light chain amyloidosis in 8 samples (57.1%) was the most diagnosed, the others being wild-type amyloid transthyretin amyloidosis in 5 samples (35.8%) and amyloid A amyloidosis in 1 sample (7.1%). The skin biopsy has an 87.5% (14 of 16) sensitivity and 100% (20 of 20) specificity, with 12.5% (2 of 16) false negatives and 0% (0 of 20) false positives in diagnosis of systemic amyloidosis. Skin biopsy from normal abdominal wall skin to evaluate dermis and fatty tissue is a safe, sensitive, and specific procedure to the diagnosis of systemic amyloidosis.

Amyloid cardiomyopathy is caused by the deposition of light chain (AL) or transthyretin amyloid (ATTR) fibrils, that leads to a restrictive cardiomyopathy, often resulting in heart failure (HF) with preserved or reduced ejection fraction. This study aimed to determine whether cardiac output reduction or ventilation inefficiency plays a predominant role in limiting exercise in patients with amyloid cardiomyopathy.

We conducted a multicentre prospective study in patients with AL or ATTR cardiomyopathy who underwent cardiopulmonary exercise testing across four centres. Patients were compared with a propensity-score matched HF cohort based on age, gender, left ventricular ejection fraction (LVEF), and peak oxygen consumption (VO2).

Data from 267 amyloid patients aged 77 (72, 81) years, 86% male, with a median N-terminal pro B-type natriuretic peptide (NT-proBNP) of 2187 (1140, 4383) ng/L, exercise parameters of peak VO2 of 14.1 (11.6;16.9) mL/min/kg, a minute ventilation to carbon dioxide production (VE/VCO2) slope of 37.4 (32.5, 42.6) and a LVEF of 50% (44%, 59%) were analysed. We identified 251 amyloid cardiomyopathy-HF matches. Amyloid patients had a signifnicantly higher VE/VCO2 slope [37.4, inter quartile range (IQR): 32.7, 43.1 vs. 32.1, IQR: 28.7, 37.0, P < 0.0001], NT-proBNP (2249, IQR: 1187, 4420 vs. 718, IQR: 405, 2161 ng/L, P < 0.001), peak heart rate (121 ± 28 vs. 115 ± 27 beats/min, P = 0.007) and peak ventilation (51, IQR: 42, 62 vs. 43, IQR: 33, 53 L/min, P < 0.0001) with earlier anaerobic threshold (VO2 at AT: 8.9, IQR: 6.8, 10.8 vs. 10.8, IQR: 8.9, 12.7 mL/min/kg, P < 0.0001) compared with HF. Between amyloid patients, AL patients (n = 27) were younger (63, IQR: 58, 70 vs. 78, IQR: 72, 81 years, P < 0.0001), had lower VE/VCO2 slope (35.0, IQR: 30.0, 38.7 vs. 38.0, IQR: 32.8, 43.1, P = 0.019), higher end-tidal carbon dioxide partial pressure both at AT (35.1 ± 4.8 vs. 31.4 ± 4.7 mmHg, P < 0.001) and peak exercise (32, IQR: 28, 35 vs. 30, IQR: 26, 33 mmHg, P = 0.039) as compared with ATTR (n = 233).

A higher VE/VCO2 slope and an earlier AT, determining functional capacity impairment, was assessed in patients with amyloid cardiomyopathy compared with the matched HF cohort. Additionally, patients with ATTR might display more severe exercise limitations as compared with AL.

To assess the effectiveness of labial minor salivary gland biopsy (LSGB) alone or in combination with punch skin biopsy (SB) for the detection of amyloid deposits in hereditary transthyretin amyloidosis with polyneuropathy (ATTRv-PN).

In this single-center retrospective study, Congo red staining of minimal invasive LSGB (4 mm) and SB (3 mm) was assessed in ATTRv-PN patients consecutively evaluated between 2012 and 2023.

Histopathological data of 171 ATTRv-PN, including 49 early-onset p.Val50Met, 58 late-onset p.Val50Met, and 64 non-p.Val50Met, were reviewed. LSGB and SB identified amyloid deposits in 123/171 (72%) and 131/171 (77%) patients respectively (p = 0.2). Combining LSGB and SB increased the amyloid detection rate to 150/171 (88%), especially in late-onset p.Val50Met (48/58 [83%]) and non-p.Val50Met patients (55/64 [86%]). LSGB and SB have a similar rate of detection of amyloid depositions in early onset p.Val50Met patients (94%). Also, the LSGB/SB combination identified amyloidosis in 89% (55/62) of early-stage ATTRv-PN patients.

In our study, combining LSGB and SB allowed the detection of amyloid deposits in 88% of ATTRv-PN patients. LSGB/SB analysis may be of major interest to confirm entry in the disease at very early-stage ATTRv-PN, with implications in disease-modifying treatment initiation.

Despite the growing availability of noninvasive and faster diagnostic modalities, biopsy remains an important tool in the diagnosis and management of liver diseases. However, it is not uncommon that liver biopsies reveal normal or near normal histologic findings in patients with abnormal liver biochemistries, elevated autoantibodies, clinical findings suggestive of portal hypertension, systemic autoimmune or inflammatory diseases, hepatomegaly, cirrhosis by imaging, or other indications. These scenarios present significant diagnostic challenges and are rarely discussed in detail in the literature or textbooks. This article aims to provide a comprehensive review of a group of selected rare liver diseases, with a focus on metabolic, storage and inclusion disorders, that may exhibit a near-normal histology on biopsy. By recognizing subtle histologic features and correlating with clinical history, laboratory results and imaging findings, it is often possible to narrow down the differential diagnosis. In many cases, this integrative approach can yield a definitive diagnosis, allowing for tailored treatment and better patient outcomes.

Providing tools for comprehensively evaluating scintigraphy images could enhance transthyretin amyloid cardiomyopathy (ATTR-CM) diagnosis. This study aims to automatically detect and score ATTR-CM in total body scintigraphy images using deep learning on multi-tracer, multi-scanner, and multi-center datasets.

In the current study, we employed six datasets (from 12 cameras) for various tasks and purposes. Dataset #1 (93 patients, 99mTc-MDP) was used to develop the 2D-planar segmentation and localization models. Dataset #2 (216 patients, 99mTc-DPD) was used for the detection (grade 0 vs. grades 1, 2, and 3) and scoring (0 and 1 vs. grades 2 and 3) of ATTR-CM. Datasets #3 (41 patients, 99mTc-HDP), #4 (53 patients, 99mTc-PYP), and #5 (129 patients, 99mTc-DPD) were used as external centers. ATTR-CM detection and scouring were performed by two physicians in each center. Moreover, Dataset #6 consisting of 3215 patients without labels, was employed for retrospective model performance evaluation. Different regions of interest were cropped and fed into the classification model for the detection and scoring of ATTR-CM. Ensembling was performed on the outputs of different models to improve their performance. Model performance was measured by classification accuracy, sensitivity, specificity, and AUC. Grad-CAM and saliency maps were generated to explain the models' decision-making process.

In the internal test set, all models for detection and scoring achieved an AUC of more than 0.95 and an F1 score of more than 0.90. For detection in the external dataset, AUCs of 0.93, 0.95, and 1 were achieved for datasets 3, 4, and 5, respectively. For the scoring task, AUCs of 0.95, 0.83, and 0.96 were achieved for these datasets, respectively. In dataset #6, we found ten cases flagged as ATTR-CM by the network. Out of these, four cases were confirmed by a nuclear medicine specialist as possibly having ATTR-CM. GradCam and saliency maps showed that the deep-learning models focused on clinically relevant cardiac areas.

In the current study, we developed and evaluated a fully automated pipeline to detect and score ATTR-CM using large multi-tracer, multi-scanner, and multi-center datasets, achieving high performance on total body images. This fully automated pipeline could lead to more timely and accurate diagnoses, ultimately improving patient outcomes.

Diagnosis and treatment of cardiac amyloidosis have rapidly evolved over the past decade by harnessing mechanisms of disease pathogenesis. Cardiac amyloidosis is caused by myocardial deposition of fibrils formed by misfolded proteins, namely transthyretin (ATTR) and immunoglobulin light chains (AL). Advances in noninvasive imaging have revolutionized diagnosis of ATTR cardiomyopathy (CM). Novel treatments for ATTR-CM utilize a range of therapeutic techniques, including protein stabilizers, interfering RNA, gene editing, and monoclonal antibodies. AL-CM, primarily driven by plasma cell dyscrasias, requires treatment with chemotherapy and consideration for autologous stem cell transplant. These incredible advances aim to improve patient outcomes in cardiac amyloidosis.

Cardiac amyloidosis (CA) is a form of infiltrative, restrictive cardiomyopathy that presents a diagnostic and therapeutic challenge in clinical practice. Historically, it has led to poor prognosis due to limited treatment options. However, advancements in disease awareness, diagnostic tools, and management approaches have led to the beginning of an era characterized by earlier diagnosis and a broader range of treatments. This article examines the advances in treating the two primary forms of cardiac amyloidosis: transthyretin cardiac amyloidosis (ATTR-CA) and light chain mediated cardiac amyloidosis (AL-CA). It highlights therapies for ATTR-CA that focus on interrupting the process of amyloid fibril formation. These therapies include transthyretin stabilizers, gene silencers, and monoclonal antibodies, which have shown the potential to improve patient outcomes and survival rates significantly. As of this writing, tafamidis is the sole Food and Drug Administration (FDA)--approved drug for ATTR-CA; however, experts anticipate several other drugs will gain approval within 1-2 years. Treatment strategies for AL-CA typically involve chemotherapy to inhibit the clonal cell type responsible for excessive AL amyloid fibril production. The prognosis for both types of amyloidosis primarily depends on how much the heart is affected, with most deaths occurring due to progressive heart failure. Effective care for CA patients requires collaboration among specialists from multiple disciplines, such as heart failure cardiology, electrophysiology, hematology/oncology, nephrology, neurology, pharmacology, and palliative care.

The ability to bring spatial resolution to omics studies enables a deeper understanding of cell populations and interactions in biological tissues. In the case of proteomics, single-cell and spatial approaches have been particularly challenging, due to limitations in sensitivity and throughput relative to other omics fields. Recent developments at the level of sample handling, chromatography, and mass spectrometry have set the stage for proteomics to be established in these new disciplines.

Cardiac amyloidosis (CA) is a progressive condition resulting from the deposition of amyloid fibrils in the heart, which leads to severe diastolic dysfunction and restrictive cardiomyopathy. The disease has two main subtypes: light-chain and transthyretin (TTR) CA, with the latter subdivided into wild-type and hereditary forms. Despite advances in diagnostic imaging, early detection remains a challenge due to non-specific symptoms that mimic other cardiac conditions. Treatment has evolved significantly with targeted therapies like TTR stabilizers, gene silencers, and RNA interference, showing promise in altering disease progression. However, barriers such as high costs, limited availability of genetic testing, and inadequate multidisciplinary care continue to impede comprehensive management. Future strategies should focus on integrating novel gene-editing therapies, expanding access to diagnostics, and enhancing multidisciplinary care models to improve outcomes. Overall, early diagnosis, equitable access to therapies, and personalized management plans are crucial to advancing care for CA patients.

Exercise capacity is related to mortality and morbidity in heart failure (HF) patients. Determinants of exercise capacity in transthyretin cardiac amyloidosis (ATTR-CA) have not been established.

This single-center study retrospectively evaluated ATTR-CA patients and patients with non-amyloidosis HF with preserved/mildly reduced ejection fraction (HFpEF/HFmrEF) (n=32 and n=51, respectively). In the ATTR-CA group, the median age was 75.5 years (interquartile range [IQR] 71.3-78.8 years), 90.6% were male, and the median left ventricular (LV) ejection fraction was 53.5% (IQR 41.4-65.6%). Cardiopulmonary exercise tests revealed a median peak oxygen consumption and anaerobic threshold of 15.9 (IQR 11.6-17.4) and 10.6 (IQR 8.5-12.0] mL/min/kg, respectively, and ventilatory efficiency (minute ventilation/carbon dioxide production [V̇E/V̇CO2] slope) of 35.5 (IQR 32.0-42.5). Among exercise variables, V̇E/V̇CO2slope has the greatest prognostic value. Univariate analysis revealed a significant correlation between V̇E/V̇CO2slope and age, LV global longitudinal strain, tricuspid annular plain systolic excursion/pulmonary arterial systolic pressure (TAPSE/PASP) ratio, and mixed venous oxygen saturation. In multivariate analyses, the TAPSE/PASP ratio was an independent predictor of V̇E/V̇CO2slope (95% confidence interval -44.5, -10.8; P=0.0067). In non-amyloidosis HFpEF/HFmrEF patients, the TAPSE/PASP ratio was not independently correlated with V̇E/V̇CO2slope.

Right ventricular-pulmonary artery coupling estimated by the TAPSE/PASP ratio determines exercise capacity in ATTR-CA patients. This highlights the importance of early therapeutic intervention against underappreciated right ventricular dysfunction associated with ATTR-CA.

Neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease, are associated with the formation of amyloid fibrils. In familial cases, the mutant causative genes accentuate disease progression through overexpression or misfolding of amyloidogenic proteins. Besides, considerable amyloidosis cases arise from external factors, but their origin and mechanisms are not yet fully understood. Herein, we found that amyloid fibrils generated from egg and milk proteins, in addition to their nutritional effects to intestinal cells, can selectively reduce the viability of nervous cells as well as pancreatic islet cells. In contrast, soy protein amyloid fibrils lacked cytotoxicity to the aforementioned cells. This protein source and cell type-dependent cytotoxicity are demonstrated to be associated with the significant upregulation of amyloidogenic proteins. The finding was also confirmed by the vein injection of beta-lactoglobulin fibrils to mice, exhibiting the pronounced upregulations of amyloid beta1-42 (Aβ1-42) and islet amyloid polypeptide in vivo. The study therefore provides insight into the health implications of exogenous amyloid fibrils.

The ISA Nomenclature Committee met at the XIX International Symposium of Amyloidosis in Rochester, MN, 27 May 2024. The in-person event was followed by many electronic discussions, resulting in the current updated recommendations. The general nomenclature principles are unchanged. The total number of human amyloid fibril proteins is now 42 of which 19 are associated with systemic deposition, while 4 occur with either localised or systemic deposits. Most systemic amyloidoses are caused by the presence of protein variants which promote misfolding. However, in the cases of AA and ATTR the deposits most commonly consist of wild-type proteins and/or their fragments. One peptide drug, previously reported to create local iatrogenic amyloid deposits at its injection site, has been shown to induce rare instances of systemic deposition. The number of described animal amyloid fibril proteins is now 16, 2 of which are unknown in humans. Recognition of the importance of intracellular protein aggregates, which may have amyloid or amyloid-like properties, in many neurodegenerative diseases is rapidly increasing and their significance is discussed.

Amyloid fibrils, historically stigmatized due to their association with diseases like Alzheimer's and Parkinson's, are now recognized as a distinct class of functional proteins with extraordinary potential. These highly ordered, cross-β-sheet protein aggregates are found across all domains of life, playing crucial physiological roles. In bacteria, functional amyloids like curli fibers are essential for surface adhesion, biofilm formation, and viral DNA packaging. Fungal prions exploit amyloid conformations to regulate translation, metabolism, and virulence, while mammalian amyloids are integral to melanin synthesis, hormone storage, and antimicrobial defense. The stability and hydrophobic nature of amyloid scaffolds underpin these diverse biological functions. Beyond their natural roles, amyloid fibrils offer unique capabilities in biomedicine, nanotechnology, and materials science. Their exceptional mechanical strength and biocompatibility make them ideal for controlled drug delivery, tissue engineering scaffolds, and enzyme immobilization. The intrinsic fluorescence and optical properties of certain amyloids open up innovative applications in biosensors, molecular probes, and optoelectronic devices. Furthermore, amyloid fibrils can template metal nanowires, enhance conducting materials, and form nanocomposites by integrating with polymers. This newfound appreciation for the functional diversity of amyloids has ignited intense research efforts to elucidate their molecular mechanisms, stability, and tunable properties. By unraveling the structural intricacies of functional amyloids, researchers aim to harness their remarkable attributes for groundbreaking biomedical therapies, advanced nanomaterials, and sustainable biotechnological innovations. This review explores the transformative journey of amyloids from pathological entities to biotechnological marvels, highlighting their vast potential across agriculture, environmental remediation, and industrial processes.

Tafamidis is used as disease-modifying treatment for patients with wild-type transthyretin cardiac amyloidosis (ATTRwt CA). However, the effects of tafamidis on exercise tolerance are unclear.

This single-center, prospective, observational study aimed to assess the effect of tafamidis on exercise tolerance in 36 patients with ATTRwt CA. Exercise tolerance was evaluated by the peak oxygen uptake (peak VO2) measured by the cardiopulmonary exercise test (CPX).

The baseline CPX showed a mean anaerobic threshold value of 11.6 ± 2.2 ml/kg/min and peak VO2 of 15.6 ± 4.1 ml/kg/min. Twenty-eight of the 36 patients underwent a follow-up CPX after 6 months. There was no significant change in peak VO2 before and 6 months after tafamidis therapy (16.0 ± 4.2 vs. 14.7 ± 4.0 ml/kg/min). The baseline CPX data showed that the mean peak VO2 was significantly lower in the increased peak VO2 group than in the non-increased peak VO2 group (13.7 ± 3.1 vs. 17.7 ± 4.1 ml/kg/min, p = 0.008). A multivariate logistic regression analysis showed that the baseline peak VO2 value was an independent predictor of improved exercise tolerance by tafamidis therapy (odds ratio: 0.646, 95 % confidence interval: 0.449-0.930, p = 0.019).

Tafamidis prevents deterioration of exercise tolerance in patients with ATTRwt CA. In some patients with ATTRwt CA, exercise tolerance may improve with the use of tafamidis, and those with lower exercise tolerance before tafamidis administration are likely to show improved exercise tolerance.

Advances in Alzheimer's disease (AD) are related to the oligomerization of Amyloid β (Aβ) peptides. Therefore, alteration of the process can prevent AD. We investigated the Aβ42 dimerization under the effects of gold nanoparticles using temperature replica-exchange molecular dynamics (REMD) simulations. The structural change of dimers in the presence and absence of the gold nanoparticle, Au55, was monitored over stable intervals. Physical insights into the oligomerization of Aβ were thus clarified. The computed metrics indicate that Au55 affects the progress of oligomerization. Specifically, the presence of the gold nanoparticle significantly modifies the structure of dimeric Aβ42. The β-content experienced a substantial decrease with the induction of Au55. The turn and coil-contents are also decreased under the effects of the gold nanoparticle. However, the α-content of the dimer exhibited a rigid increase. The influence of gold nanoparticles on the dimeric Aβ42 differs significantly from that of silver nanoparticles, which reduce β-content but increase coil-, turn-, and α-contents. The nature of inhibition will be discussed, in which the vdW interaction plays a driving force for the interaction between the Aβ42 dimer and the gold nanoparticle.

Amyloidosis derived from abnormal extracellular fibril deposits may contribute to multiple organ dysfunctions. The recognition of amyloidosis-associated orofacial changes may be beneficial for the early diagnosis of this systemic pathology and the underlying diseases. This retrospective study aimed to determine the characteristics of orofacial amyloidosis to aid dentists in the recognition of this disease. Seven patients consulting the Department of Oral Medicine and Oral Surgery at Sahloul Hospital from January 2010 to January 2019 and diagnosed with systemic amyloidosis were included. The median age of onset, the most commonly affected sites, the predominant oral features of amyloidosis, and its complications were presented. The results of minor salivary gland and tongue biopsies were evaluated. Macroglossia was the most frequent oral lesion and it was associated with AL amyloidosis in 5 cases. Minor salivary gland biopsy was positive in four cases. We concluded that the dentist, especially the oral pathologist, has an important role in the evaluation of the local alterations that may reflect the patients´ systemic deterioration.

Amyloidosis is a rare multisystem disorder characterized by extracellular accumulation of insoluble fibrils in various organs and tissues. The most common subtype in the pediatric population is systemic reactive amyloidosis, typically developing secondary to chronic inflammatory conditions and resulting in deposition of serum amyloid A protein in association with apolipoprotein HDL3. Clinical presentation is highly variable and is mostly influenced by specific organs involved, precursor protein type, and extent of amyloid deposition, often closely reflecting clinical features of the underlying disease. The most critical determinants of prognosis are cardiac and renal involvement. Diagnosis of amyloidosis is confirmed by tissue biopsy, which remains the gold standard, followed by precise amyloid fibril typing. The primary therapeutic approach is directed towards controlling underlying disease and reducing serum levels of precursor proteins to prevent further amyloid deposition. This study aims to highlight the main clinical characteristics of amyloidosis with onset in childhood, emphasizing the key differences compared to adult form.

Transthyretin (ATTR) amyloidosis constitutes a spectrum of debilitating neurodegenerative diseases instigated by systemic extracellular deposition of partially unfolded/aggregated aberrant transthyretin. The homotetrameric protein, TTR, is abundant in the plasma, and to a lesser extent the cerebrospinal fluid. Rate-limiting tetramer dissociation of the native protein is regarded as the critical step in the formation of morphologically heterogenous toxic aggregates and the onset of clinical manifestations such as polyneuropathy, cardiomyopathy, disturbances in motor and autonomic functions. Over the past few decades there has been increasing evidence suggesting that in addition to destabilization in TTR tetramer structure, oxidative stress may also play an important role in the pathogenesis of ATTR amyloidosis. In this review, an update on the impact of oxidative stress in TTR amyloidogenesis as well as TTR aggregate-mediated pathologies is discussed. The counteracting effects of antioxidants and nutraceutical agents explored in the treatment of ATTR amyloidosis based on recent evidence is also critically examined. The insights unveiled could further strengthen current understanding of the mechanisms underlying ATTR amyloidosis as well as extend the range of strategies for effective management of ATTR amyloidoses.

Localized gastrointestinal tract amyloidosis is uncommon and little is known regarding this entity. There is no current standard of care for the management of localized amyloidosis. The objective of this study was to evaluate the characteristics, available treatments, outcomes and surveillance of these patients.

We conducted a systematic review of cases reported in the literature from 1962 to 2021. Patients with gastrointestinal amyloidosis reported in English literature were included in the analysis. We described and summarized the patient's characteristics, treatments, clinical presentations, outcomes and surveillance.

The systematic review of reported clinical cases included 62 patients. In these patients, the most common site of amyloid deposition was the stomach (42%). The median age of diagnosis is 64.4 years old; there is a 2:1 prevalence among males (63%) to females (37%); abdominal pain is the most common type of presentation (41%), although patients could also be asymptomatic. There is a high curative rate (100%) with resection alone. Among patients treated with a type of systemic therapy, 80% achieved a complete response. The minority of cases reported a type of surveillance post treatment, and among those 62% pursued serial clinical evaluations alone.

To our knowledge, this is the first and largest systematic review of the literature in gastrointestinal tract amyloidosis. This is more common among males and seems to have an excellent curative rate (100%) with surgery alone. Systemic therapy is an option for those with non-resectable amyloidomas. Serial clinical evaluations should be part of the standard surveillance care in these patients.

To evaluate different cardiovascular magnetic resonance (CMR) parameters for the differentiation of light chain amyloidosis (AL) and transthyretin-related amyloidosis (ATTR).

In total, 75 patients, 53 with cardiac amyloidosis {20 patients with AL [66 ± 12 years, 14 males (70%)] and 33 patients with ATTR [78 ± 5 years, 28 males (88%)]} were retrospectively analysed regarding CMR parameters such as T1 and T2 mapping, extracellular volume (ECV), late gadolinium enhancement (LGE) distribution patterns, and myocardial strain, and compared to a control cohort with other causes of left ventricular hypertrophy {LVH; 22 patients [53 ± 16 years, 17 males (85%)]}. One-way ANOVA and receiver operating characteristic analysis were used for statistical analysis. ECV was the single best parameter to differentiate between cardiac amyloidosis and controls [area under the curve (AUC): 0.97, 95% confidence intervals (CI): 0.89-0.99, P < 0.0001, cut-off: >30%]. T2 mapping was the best single parameter to differentiate between AL and ATTR amyloidosis (AL: 63 ± 4 ms, ATTR: 58 ± 2 ms, P < 0.001, AUC: 0.86, 95% CI: 0.74-0.94, cut-off: >61 ms). Subendocardial LGE was predominantly observed in AL patients (10/20 [50%] vs. 5/33 [15%]; P = 0.002). Transmural LGE was predominantly observed in ATTR patients (23/33 [70%] vs. 2/20 [10%]; P < 0.001). The diagnostic performance of T2 mapping to differentiate between AL and ATTR amyloidosis was further increased with the inclusion of LGE patterns [AUC: 0.96, 95% CI: (0.86-0.99); P = 0.05].

ECV differentiates cardiac amyloidosis from other causes of LVH. T2 mapping combined with LGE differentiates AL from ATTR amyloidosis with high accuracy on a patient level.

Extracellular vesicles (EV) are a heterogeneous group of lipid particles excreted by cells. They play an important role in regeneration, development, inflammation, and cancer progression, together with the extracellular matrix (ECM), which they constantly interact with. In this review, we discuss direct and indirect interactions of EVs and the ECM and their impact on different physiological processes. The ECM affects the secretion of EVs, and the properties of the ECM and EVs modulate EVs' diffusion and adhesion. On the other hand, EVs can affect the ECM both directly through enzymes and indirectly through the modulation of the ECM synthesis and remodeling by cells. This review emphasizes recently discovered types of EVs bound to the ECM and isolated by enzymatic digestion, including matrix-bound nanovesicles (MBV) and tissue-derived EV (TiEV). In addition to the experimental studies, computer models of the EV-ECM-cell interactions, from all-atom models to quantitative pharmacology models aiming to improve our understanding of the interaction mechanisms, are also considered. STATEMENT OF SIGNIFICANCE: Application of extracellular vesicles in tissue engineering is an actively developing area. Vesicles not only affect cells themselves but also interact with the matrix and change it. The matrix also influences both cells and vesicles. In this review, different possible types of interactions between vesicles, matrix, and cells are discussed. Furthermore, the united EV-ECM system and its regulation through the cellular activity are presented.

Sustained ventricular tachycardia (VT) in cardiac amyloidosis is uncommon, and the substrate and outcomes of catheter ablation are not defined.

We included 22 consecutive patients (mean age, 68±10 years; male sex, 91%) with cardiac amyloidosis (ATTR [transthyretin], n=16; light chain, n=6) undergoing catheter ablation for VT/ventricular fibrillation (VF) between 2013 and 2023 in a retrospective, observational, international study. The primary efficacy outcome was recurrent VT/VF during follow-up, while the primary safety end point included major procedure-related adverse events.

The indication for ablation was drug-refractory VT in 17 patients (77%), and premature ventricular complex-initiated polymorphic VT/VF in 5 patients (23%). Catheter ablation was performed using endocardial (n=17.77%) or endo-epicardial approaches (n=5.23%). Complete endocardial electroanatomical voltage maps of the left and right ventricles were obtained in 17 (77%) and 10 (45%) patients, respectively. Each patient had evidence of low-voltage areas, most commonly involving the interventricular septum (n=16); late potentials were recorded in 16 patients (73%). A median of 1 (1-2) VT was inducible per patient; 12 of the 26 mappable VTs (46%) originated from the interventricular septum. Complete procedural success was achieved in 16 patients (73%), with 4 (18%) major procedure-related adverse events. After a median follow-up of 32 (14-42) months, sustained VT/VF recurrence was observed in 9 patients (41%); survival free from VT/VF recurrence was 56% (95% CI, 36%-86%) at 36-month follow-up, and most patients remained on antiarrhythmic drugs. A significant reduction in per patient implantable cardioverter defibrillator therapies was noted in the 6-month period after ablation (before: 6 [4-9] versus after: 0 [0-0]; P<0.001). In multivariable analysis, complete procedural success was associated with reduced risk of recurrent VT/VF (hazard ratio, 0.002; P=0.034).

Catheter ablation can achieve control of recurrent VT/VF in more than half of patients with cardiac amyloidosis, and the reduction in VT/VF burden post-ablation may be relevant for quality of life. Septal substrate and risk of procedure-related complications challenge successful management of patients with cardiac amyloidosis and VT/VF.

Alpha-synuclein (α-syn) aggregation plays a critical role in the pathogenicity of Parkinson's Disease (PD). This study aims to evaluate the aggregation propensity of α-syn fragment peptides designed using the variability found in humans and animals. Thioflavin T (ThT) and transmission electron microscopy (TEM) were used to validate the formation of fibrils to identify important amino acid residues. Human α-syn fragments 51-75, 37-61, 62-86, 76-100, and 116-140 demonstrate a significantly higher tendency to aggregate compared to fragments 1-25, 26-50, and 91-115. All species analyzed of the α-syn 37-61 and 62-86 regions were shown to form fibrils on both ThT and TEM. The α-syn 37-61 and 62-86 fragment regions exhibited a high susceptibility to aggregation, with fibril formation observed in all species. The A53T mutation in several α-syn 37-61 fragments may enhance their propensity for aggregation, suggesting a correlation between this mutation and the capacity for fibril formation. Furthermore, the presence of the non-amyloid-β component (NAC) region, specifically in α-syn 62-86, was consistently observed in several fragments that displayed fibril formation, indicating a potential correlation between the NAC region and the process of fibril formation in α-syn. Finally, the combination of a high quantity of valine and a low quantity of acidic amino acids in these fragments may serve as indicators of α-syn fibril formation.

Patients with transthyretin amyloid cardiomyopathy (ATTR-CM) experience reduced functional capacity. We evaluated changes in functional capacity over extensive follow-up using cardiopulmonary exercise testing (CPX).

ATTR-CM patients underwent CPX and blood testing at baseline, first [V1, 8 (6-10) months] and second follow-up (V2) at 35 (26-41) months after start of disease-specific therapy.

We included 34 ATTR-CM patients, aged 77 (±6) years (88.2% men). CPX showed two patterns with functional capacity improvement at V1 and deterioration at V2. Peak work capacity ( P = 0.005) and peak oxygen consumption (VO 2 , P = 0.012) increased at V1 compared with baseline and decreased at V2. The ventilation to carbon dioxide relationship slope (VE/VCO 2 ) increased at V2 compared with baseline and V1 ( P = 0.044). A cut-off for peak VO 2 at 14 ml/kg·min showed more events (composite of death and heart failure hospitalization): less than 14 vs. greater than 14 ml/kg·min ( P  = 0.013). Cut-offs for VE/VCO 2 slope at 40 showed more events greater than 40 vs. less than 40 ( P  = 0.009).

ATTR-CM patients showed an improvement and deterioration in the short-term and long-term follow-up, respectively, with a better prognosis for those with peak VO 2 above 14 ml/kg·min and for a VE/VCO 2 slope below 40.

The goal of this research was to study the effect of different doses of resveratrol (RS) and RS with donepezil (DPZ) on the deposition of amyloid beta (Aβ) and neurofibrillary tangles (NFTs) in colchicine-induced Alzheimer's disease (AD) brain. The study included three months old male Albino Wistar rats and consisted of six animal groups: AD model (group 1), treatment groups, RS 10 mg/kg body weight (group 2), RS 20 mg/kg body weight (group 3), RS 10 mg/kg body weight along with DPZ 1 mg/kg body weight (group 6), prophylaxis groups, RS 10 mg/kg body weight (group 4) and RS 20 mg/kg body weight (group 5). In the treatment groups, RS was given for 7 consecutive days from the day of induction of AD, and in the prophylaxis groups, we started RS 7 days even before the induction of AD and continued for seven days after the induction. The number of Aβs and NFTs at the frontal region, cornu ammonis (CA) 1,2,3,4 and dentate gyrus regions of hippocampus were evaluated. The immunohistochemical analysis was performed by using mouse anti-β-amyloid antibody for the Aβ plaques and polyclonal rabbit anti-human tau for the tau-positive neurons. The present study observed the accumulation of Aβ plaques and tau-positive neurons in the AD model. However, their numbers were significantly decreased in the treatment groups (p < 0.001). The best results were observed when RS 10 mg was given prophylactically (p < 0.01) and RS along with DPZ (p < 0.001), suggesting the neuroprotective effect of RS and its synergistic effect with the DPZ.

Light chain (AL) amyloidosis stands as the most prevalent subtype of systemic amyloidosis, encompassing a group of rare diseases. Here, we evaluated the scientific landscape of AL amyloidosis to investigate research trends and identify hotspots within the field.

Relevant studies on AL amyloidosis published over the past two decades were retrieved from the Web of Science Core Collection. The publications between 2005 and 2024 were subjected to bibliometric analyses, leveraging tools including CiteSpace, VOSviewer, RStudio and MS Excel to analyse and visualize the annual publication trend, co-occurrence patterns, collaborative networks among countries, organizations, and authors. Burst keywords and references were also examined to obtain the research history, and emerging hotspots.

The bibliometric analysis included 2,864 articles published between 2005 and 2024. The most productive journal is Amyloid-Journal of Protein Folding Disorders. The United States, along with several developed nations, emerges as a dominant force in international AL amyloidosis research. "AL amyloidosis" and "cardiac amyloidosis" were the primary hotspots over the past two decades, and "Biomarkers," "Cardiac amyloidosis," and "treatment" would be future trends.

This bibliometric analysis examined the research developments in AL amyloidosis over the past two decades using bibliometric software. Recent research in this field primarily focuses on two main areas: clinical diagnosis and treatment of AL amyloidosis, as well as cardiac amyloidosis. Emphasis is placed on understanding the mechanisms underlying immunoglobulin light chain aggregation and deposition to mitigate organ involvement.

Amyloidosis is a disease characterized by local and systemic extracellular deposition of amyloid protein fibrils where its excessive accumulation in tissues and resistance to degradation can lead to organ failure. Diagnosis is challenging because of approximately 36 different amyloid protein subtypes. Imaging methods like immunohistochemistry and the use of Congo red staining of amyloid proteins for laser capture microdissection combined with liquid chromatography tandem mass spectrometry (LMD/LC-MS/MS) are two diagnostic methods currently used depending on the expertise of the pathology laboratory. Here, we demonstrate a streamlined in situ amyloid peptide spatial mapping by Matrix Assisted Laser Desorption Ionization-Mass Spectrometry Imaging (MALDI-MSI) combined with Trapped Ion Mobility Spectrometry for potential transthyretin (ATTR) amyloidosis subtyping. While we utilized the standard LMD/LC-MS/MS workflow for amyloid subtyping of 31 specimens from different organs, we also evaluated the potential introduction in the MS workflow variations in data acquisition parameters like dynamic exclusion, or testing Data Dependent Acquisition combined with High-Field Asymmetric Waveform Ion Mobility Spectrometry (DDA FAIMS) versus Data Independent Acquisition (DIA) for enhanced amyloid protein identification at shorter acquisition times. We also demonstrate the use of Mascot's Error Tolerant Search and PEAKS de novo sequencing for the sequence variant analysis of amyloidosis specimens.

Amyloidosis is a heterogenous group of disorders, caused by the deposition of insoluble fibrils derived from misfolded proteins in the extracellular space of various organs. These proteins have an unstable structure that causes them to misfold, aggregate, and deposit as amyloid fibrils with the pathognomonic histologic property of green birefringence when viewed under cross-polarized light after staining with Congo red. Amyloid fibrils are insoluble and degradation-resistant; resistance to catabolism results in progressive tissue amyloid accumulation. The outcome of this process is organ disfunction independently from the type of deposited protein, however there can be organ that are specifically targeted from certain proteins.

Cardiac computed tomography (CCT) has assumed an increasingly significant role in the evaluation of coronary artery disease (CAD) during the past few decades, whereas cardiovascular magnetic resonance (CMR) remains the gold standard for myocardial tissue characterization. The discovery of late myocardial enhancement following intravenous contrast administration dates back to the 1970s with ex-vivo CT animal investigations; nevertheless, the clinical application of this phenomenon for cardiac tissue characterization became prevalent for CMR imaging far earlier than for CCT imaging. Recently the technical advances in CT scanners have made it possible to take advantage of late contrast enhancement (LCE) for tissue characterization in CCT exams. Moreover, the introduction of extracellular volume calculation (ECV) on cardiac CT images combined with the possibility of evaluating cardiac function in the same exam is making CCT imaging a multiparametric technique more and more similar to CMR. The aim of our review is to provide a comprehensive overview on the role of CCT with LCE in the evaluation of a wide range of cardiac conditions.

Protein misfolding and amyloid formation are implicated in the protein dysfunction, but the underlying mechanism remains to be clarified due to the lack of effective tools for detecting the transient intermediates. Sum frequency generation vibrational spectroscopy (SFG-VS) has emerged as a powerful tool for identifying the structure and dynamics of proteins at the interfaces. In this review, we summarize recent SFG-VS studies on the structure and dynamics of membrane-bound proteins during misfolding processes. This paper first introduces the methods for determining the secondary structure of interfacial proteins: combining chiral and achiral spectra of amide A and amide I bands and combining amide I, amide II, and amide III spectral features. To demonstrate the ability of SFG-VS in investigating the interfacial protein misfolding and amyloid formation, studies on the interactions between different peptides/proteins (islet amyloid polypeptide, amyloid β, prion protein, fused in sarcoma protein, hen egg-white lysozyme, fusing fusion peptide, class I hydrophobin SC3 and class II hydrophobin HFBI) and surfaces such as lipid membranes are discussed. These molecular-level studies revealed that SFG-VS can provide a unique understanding of the mechanism of interfacial protein misfolding and amyloid formation in real time, in situ and without any exogenous labeling.

Renal amyloidosis is a set of complex disorders characterized by the deposition of amyloid proteins in the kidneys, which causes gradual organ damage and potential kidney failure. Recent developments in diagnostic methods, particularly mass spectrometry and proteome profiling, have greatly improved the accuracy of amyloid typing, which is critical for disease management. These technologies provide extensive insights into the specific proteins involved, allowing for more targeted treatment approaches and better patient results. Despite these advances, problems remain, owing to the heterogeneous composition of amyloid proteins and the varying efficacy of treatments based on amyloid type. Access to sophisticated diagnostics and therapy varies greatly, highlighting the global difference in renal amyloidosis management. Future research is needed to investigate next-generation sequencing and gene-editing technologies, like clustered regularly interspaced short palindromic repeats (CRISPR), which promise more profound insights into the genetic basis of amyloidosis.

Amyloidosis can affect any organ in the body by deposition of amyloid fibrils. When these aggregate in the heart, it leads to cardiac amyloidosis a life-threatening and progressive disease. Although considered a rare condition, advances in imaging techniques and raised awareness have shown that it might be more frequent than has been historically estimated. Cardiac amyloidosis can be hereditary or occur as a consequence of the ageing process but, regardless of type, patients experience a heavy symptomatic burden. This article provides an overview of its pathophysiology, signs and symptoms and how any nurse can look for the main red flags in clinical practice. Early referral for specialist care can have a significant impact on disease progression and patient quality of life.

The aggregation of amyloid beta (Aβ) peptides is associated with the development of Alzheimer's disease (AD). However, there has been a growing belief that the oligomerization of Aβ species in different environments has a neurotoxic effect on the patient's brain, causing damage. It is necessary to comprehend the compositions of Aβ oligomers in order to develop medications that may effectively inhibit these neurotoxic forms that affect the nervous system of AD patients. Thus, dissociation or inhibition of Aβ aggregation may be able to prevent AD. To date, the search for traditional agents and biomolecules has largely been unsuccessful. In this context, nanoparticles have emerged as potential candidates to directly inhibit the formation of Aβ oligomers. The oligomerization of the dimeric Aβ peptides with or without the influence of a silver nanoparticle was thus investigated using temperature replica-exchange molecular dynamics (REMD) simulations. The physical insights into the dimeric Aβ oligomerization were clarified by analyzing intermolecular contact maps, the free energy landscape of the dimeric oligomer, secondary structure terms, etc. The difference in obtained metrics between Aβ with or without a silver nanoparticle provides a picture of the influence of silver nanoparticles on the oligomerization process. The underlying mechanisms that are involved in altering Aβ oligomerization will be discussed. The obtained results may play an important role in searching for Aβ inhibitor pathways.

Amyloid is an extracellular deposition of Congo red positive material which shows apple green birefringence under polarized light. A cytopathologist can uncommonly encounter such cases. Among the reported cases, a fine-needle aspiration (FNA) of amyloid is frequently misinterpreted as acellular nondiagnostic material. We report a case of amyloidoma of the right upper arm in a 68-year-old man with history of renal transplantation for diabetic nephropathy who presented with loss of appetite and weight loss. Physical exam showed a 7 cm hard nodular subcutaneous mass in the right upper arm. FNA yielded abundant acellular, irregular fragments of dense material, which was Congo red positive with apple green birefringence by polarized light, consistent with amyloid. Further subtyping of the amyloid by mass spectrometry, showed AIns (insulin)-type amyloid deposition. After further questioning, the patient admitted to injecting insulin at the same site for many years. Awareness of the cytological features is important for diagnosis. This is especially important when dealing with uncommon sites and without adequate clinical information.

Amyloidosis is the condition when starch-like misfolded proteins form insoluble fibrils that deposit in tissues and cause dysfunction. Cardiac amyloidosis occurs due to the deposition of amyloid fibrils at the cardiac level and is an important cause of heart failure. This case reveals a patient with significant heart failure and arrhythmia, which later on turned out to be caused by cardiac amyloidosis. While regarded as a rare disease in practice, in retrospect, there are a lot of signs and imaging indicators, particularly in echocardiography that warrant an investigation of cardiac amyloidosis. In this case review, red flags in echocardiography that should endorse further testing for underlying cardiac amyloidosis are highlighted.

Human cystatin C (hCC), a small secretory protein, has gained attention beyond its classical role as a cysteine protease inhibitor owing to its potential involvement in neurodegenerative disorders. This study investigates the interaction between copper(II) ions [Cu(II)] and hCC, specifically targeting histidine residues known to participate in metal binding. Through various analytical techniques, including mutagenesis, circular dichroism, fluorescence assays, gel filtration chromatography, and electron microscopy, we evaluated the impact of Cu(II) ions on the structure and oligomerization of hCC. The results show that Cu(II) does not influence the secondary and tertiary structure of the studied hCC variants but affects their stability. To explore the Cu(II)-binding site, nuclear magnetic resonance (NMR) and X-ray studies were conducted. NMR experiments revealed notable changes in signal intensities and linewidths within the region 86His-Asp-Gln-Pro-His90, suggesting its involvement in Cu(II) coordination. Both histidine residues from this fragment were found to serve as a primary anchor of Cu(II) in solution, depending on the structural context and the presence of other Cu(II)-binding agents. The presence of Cu(II) led to significant destabilization and altered thermal stability of the wild-type and H90A variant, confirming differentiation between His residues in Cu(II) binding. In conclusion, this study provides valuable insights into the interaction between Cu(II) and hCC, elucidating the impact of copper ions on protein stability and identifying potential Cu(II)-binding residues. Understanding these interactions enhances our knowledge of the role of copper in neurodegenerative disorders and may facilitate the development of therapeutic strategies targeting copper-mediated processes in protein aggregation and associated pathologies.

Introduction. Cardiac amyloidosis is a lethal disease, the incidence of which is increasing every year. Early diagnosis and treatment are the keys to reducing the mortality of this disease. Methods. Relevant English literature published in Embase, PubMed, Cochrane Library, and Web of Science were searched until December 1, 2022. Meta-analysis was performed with Stata 17.0 software. Results. A total of 1060 patients with 5 articles were included in this study. The sensitivity of abdominal fat aspiration biopsy for the diagnosis of cardiac amyloidosis was 0.66 (0.48-0.84) and the sensitivity for light chain amyloidosis cardiomyopathy and transthyretin amyloidosis cardiomyopathy was 0.90 (0.80-0.97) and 0.39 (0.18-0.60), respectively. Conclusion. Abdominal fat aspiration biopsy has high sensitivity and clinical value in the diagnosis of light chain amyloidosis cardiomyopathy, whereas there are limitations in the diagnosis of transthyretin amyloidosis cardiomyopathy.

Reduced exercise tolerance is one of the hallmarks of patients with cardiac amyloidosis (CA), but detailed biological responses during exercise were not investigated. The purpose of this study was to compare the cardiopulmonary exercise test (CPX) parameters between CA patients and propensity-matched heart failure patients. This was a single-center, retrospective, observational study of patients diagnosed with CA. The control group was extracted by propensity score matching from patients who underwent CPX for chronic heart failure during the same period. Clinical data including assessment of biological responses during CPX were compared between the patients with CA (CA group, n = 16) and the control group (non-CA group, n = 16). Echocardiography suggested more impaired diastolic function in the CA group than in the non-CA group. There was no significant difference between groups in the fraction of end-tidal carbon dioxide (FETCO2) at rest. However, the difference between the FETCO2 at rest and the FETCO2 at the respiratory compensation point (ΔFETCO2) was significantly smaller in the CA group than in the non-CA group (0.40% ± 0.37% vs. 0.82% ± 0.33%; p = 0.002). Only in the CA group, there was a significant negative correlation between the ΔFETCO2 and the E/e' ratio on echocardiography (r = - 0.521; p = 0.039) and the serum high-sensitivity troponin T concentration (r = - 0.501; p = 0.048). In conclusion, patients with CA may find it difficult to increase cardiac output during exercise due to severe diastolic dysfunction.