Deposition Of Fibrils Research Articles

A review of recent clinical trials to evaluate disease-modifying therapies in the treatment of cardiac amyloidosis

Cardiac amyloidosis (CA) is a serious condition that results in infiltrative cardiomyopathy and heart failure with preserved ejection fraction (HFpEF) that is caused by the extracellular deposition of amyloid fibrils within heart tissue. While many important features of CA have been known for years, its prevalence in elderly patients with HF is increasingly being recognized. Plasma cells produce monoclonal immunoglobulin light chains which results in the formation and aggregation of amyloid fibrils that are responsible for AL amyloidosis. CA is classified as originating from either transthyretin (ATTR) or light chain (AL) amyloidosis. ATTR CA may result from a genetic mutation in the TTR gene, which is inherited (ATTRv), or from age-related deposition from wild-type ATTR (ATTRwt). Cardiac involvement in AL amyloidosis is attributed to either of two mechanisms: the extracellular deposition of amyloid fibril in the myocardium, or direct cardiotoxicity from the fibril aggregates. Typing of amyloid fibrils, a critical determinant of therapy, has also improved with wider availability of laser capture and mass spectrometry of histologic specimens. Specific and accurate evaluation of CA is now possible using cardiac magnetic resonance imaging and bone scintigraphy tracers. Survival in CA has improved markedly as novel chemotherapy agents have become available, but challenges remain in advanced disease. Broadening the amyloid-specific therapeutic landscape to include RNA inhibitors, fibril formation stabilizers and inhibitors, and immunotherapeutic targeting of amyloid deposits holds promise and may improve outcomes in systemic and cardiac amyloidoses. Treatment strategies for CA has recently undergone transformative changes, leading to some progress in outcomes for certain patients. Here, we discuss the basic features of CA as well as the emergence of novel, disease-modifying strategies that have been recently evaluated in clinical trials for the treatment of CA.

Biomarkers for monitoring patients with cardiac amyloidosis during transthyretin-stabilizer therapy

Abstract Introduction Cardiac amyloidosis is characterized by deposition of amyloid fibrils in the heart, leading to structural abnormalities and functional impairments resulting in heart failure. Amyloid transthyretin amyloidosis cardiomyopathy (ATTR-CM) is the most common form with increasing incidence due to growing awareness and improved diagnosis. The ATTR stabilizer tafamidis serves as the first specific therapy approved for ATTR-CM, and many promising substances are in late-stage clinical trials. With growing numbers of patients receiving stabilizer therapy, valid tools for monitoring treatment response and detecting disease progression are currently lacking. Here, we aim to assess systemic and cardiac biomarkers in patients receiving stabilizer therapy. Method All individuals diagnosed with ATTR-CM at our university hospital, were systematically assessed for eligibility in this study. We enrolled patients who were undergoing therapy with tafamidis. Biomarkers including Hemoglobin (Hb), Creatinine, estimated glomerular filtration rate (eGFR), International Normalized Ratio (INR), C-reactive protein (CRP), Troponin and NT-proBNP were examined at baseline and during 6 and 12 months follow-up. Wilcoxon signed rank test was used for statistical analysis. The study was approved by the local ethics committee (23-11500-BO). Results 194 patients were included in the analysis with median age of 80 (76-83) years (86,6% male). Results showed an impaired renal function at baseline (all mean ± SD) with creatinine 1.24 ± 0.46 mg/dl and eGFR 58.64 ± 18.24 ml/min/kg with statistically significant increase after 6 months in creatinine (1.31 ± 0.51 mg/dl, p<0.001) and eGFR (55.06 ± 17.65 ml/min/kg, p<0.001) and after 12 months (creatinine 1.35 ± 0.54 mg/dl, p<0.001, eGFR 53.27 ± 17.68 ml/min/kg, p<0.001). Hb showed a significant increase after 6 (13.61 ± 1.78 g/dl, p<0.001) and 12 months (13.6 ± 1.79 g/dl, p<0.001), compared to baseline (13.41 ± 1.71 g/dl, p<0.001). Comparison of baseline values for CRP (0.08 ± 1.18 mg/dl), Troponin (86.33 ± 190.6 ng/l), NT-pro BNP (4703 ± 4385 pg/ml) and INR (1.25 ± 0.46) after 6 (CRP p=0.28, Troponin p=0.7, NT-pro BNP p=0.97, INR p=0.91) and 12 months (CRP p=0.12, Troponin p=0.59, NT-pro BNP p=0.78, INR p=0.28) showed no significant changes. Conclusion Although troponin and BNP are routinely used and recommended as biomarker for monitoring patients with ATTR-CM, the diagnostic value may be insufficient to assess therapy response. Results emphasize the need to identify new biomarkers to adequately reflect the specific aspects of ATTR-CM disease progression. This study reveals significant alterations in creatinine and eGFR due to a worsening of kidney function, but an increase of Hb, suggesting a potential indicator for treatment response. Future research should explore innovative approaches like proteomic analysis as promising approach for both diagnostic and prognostic biomarkers.

RV-PA uncoupling is a strong predictor of 3-year all-cause mortality in transthyretin amyloid cardiomyopathy

Abstract Background Right ventricle to pulmonary artery coupling (RV-PAc) describes the right ventricle's ability to adjust to an increased afterload which, in case of transthyretin amyloid cardiomyopathy (ATTR-CM), can result from increased left ventricular diastolic stiffness due to fibril deposition. While RV-PAc is a validated prognostic parameter in pulmonary arterial hypertension (PAH), its prognostic relevance in ATTR-CM remains unclear. This study sought to evaluate the prognostic implications of impaired RV-PAc on survival in ATTR-CM. Methods In this two-centre study, RV-PAc was investigated by the echocardiographic surrogate of ratio of tricuspid annular plane systolic excursion to estimated pulmonary arterial systolic pressure (TAPSE/PASP) in 418 ATTR-CM patients, all treated with TTR stabilizer. The primary outcome was all-cause mortality. Receiver operation curves and Youden’s J analysis were applied to identify an optimal cut-off value of RV-PAc ratio. Results Within a median time of 631 (IQR 361-983) days after diagnosis, 14.4% of patients died. RV-PAc ratio at first presentation emerged as a robust marker for risk stratification with a determined optimal cut-off of 0.382mm/mmHg (area under the curve (AUC) 0.746, 95% CI 0.68-0.82). Patients with RV-PAc ratio ≤0.382mm/mmHg (impaired RV-PAc, n=158) exhibited significantly lower survival (HR 4.07, 95% CI 2.26-7.33, p<0.001) within 3 years of follow up than those with RV-PAc ratio > 0.382mm/mmHg. In multivariate Cox regression analysis, incorporating a range of known prognostic variables, reduced RV-PAc was a strong echocardiographic predictor of mortality (Hazard Ratio (HR) 2.99, 95% Confidence Interval (CI) 1.63-5.51, p <0.001). Conclusion Impaired adaption of the RV to increased afterload is associated with worse outcome in ATTR-CM patients. RV-PAc ratio can serve as an echocardiographic predictor for all-cause mortality within three years after diagnosis. Therefore, determination of RV-PAc could improve risk stratification for ATTR-CM patients.Figure_1_Kaplan-Meier curves

In-depth morphological and functional analysis of ATTR-CA myocardial cells and niche by electron microscopic 3D reconstruction

Abstract Background Cell-cell interactions and interplay with extracellular matrix are known to be important in the steady state and pathological conditions, including wild-type transthyretin cardiac amyloidosis (wtATTR-CA). However, alterations of the microstructure of cardiomyocytes (CMs) and cardiac niches have not been well analyzed. Normal histological staining is usually limited in resolution, and 2D electron microscopy cannot capture stereoscopic images or the distribution of target particles and organelles in intra- and extracellular 3D space, so novel methods are being attempted. Methods and Results Using Serial Block Face-Scanning Electron Microscopy (SBF-SEM) and a 3D structural reconstruction system, we for the first time investigated the microstructure of human myocardial tissue from control hypertrophied heart (hypertensive heart disease) and wtATTR-CA patients. The microstructure of myocardial niche, cell morphology/numbers, and the distribution of intracellular organelles such as intercalated discs (ICDs) were compared to control endomyocardial biopsy (EMB) samples (2 controls vs 5 wtATTR-CA patients). In all wtATTR-CA samples, amyloid fibers were deposited originating around the capillary structures with various electron densities, compressing myocardial cells not only from the periphery but also dividing them from the center of the cell body, and CMs showed degeneration and dwarfing according to the severity of amyloid fiber deposition (Figure 1). The capillary structures showed degeneration and narrowing with stratified basement membrane, and rarefaction (3378±216.5 vs 1448±116.8/mm2, p<0.0001). Notably, the stromal cells (pericytes, fibroblasts, macrophages) were more likely buried by amyloid fibers than CMs, and their numbers were also reduced, indicating a loss of adjacent and intercellular interaction with capillaries and CMs (Fig. 2, 1892±194.4 vs 1189±107.4 mm2, p=0.0043). This method can also be used to analyze intracellular organelles and microstructures in CMs. In ATTR-CA, morphological abnormalities were observed in ICDs (Figure 3) and mitochondria. Conclusion In the ATTR-CM patients, there was a significant decrease in the number of capillaries in accordance with the deposition of myocardial amyloid fibers, as well as a decrease in stromal cells. These results support the hypothesis that amyloid fibril deposition not only causes chronic myocardial ischemia, but also reduces the number of niche cells, which play a supportive role for CM function and entirely exacerbate the damage. The SBF-SEM is an innovative tool for 3D imaging and quantitative analysis of myocardial ultrastructure and functions.Methods & Figure 1Figure 2 and Figure 3

Microvascular obstruction in cardiac amyloidosis.

Cardiac amyloidosis (CA) is characterized by deposition of amyloid fibrils within the extracellular space, causing disarray of the myocardial structure and capillary architecture. This study aims to characterize the prevalence of microvascular obstruction (MVO) in patients with CA and to assess the association between MVO and prognosis. The study population comprised 800 patients, of which 400 had light-chain CA (AL-CA) and 400 had transthyretin CA (ATTR-CA). MVO was present in 221 (27.6%) patients, and more common in ATTR-CA than AL-CA (124 [56.1%] vs. 97 [43.9%], p = 0.033). Patients with MVO had a more severe cardiac phenotype evidenced by higher N-terminal pro-brain natriuretic peptide (3516 ng/L [1944-6247] vs. 2508 ng/L [1203-5752], p < 0.001), worse global longitudinal strain (-10.5% [-12.6; -7.9] vs. -12.0% [-16.0; -8.9], p < 0.001), and higher extracellular volume (56% [51-61] vs. 50% [45-57], p < 0.001). Patients with AL-CA and MVO had a higher serum troponin (86 ng/L [47-148] vs. 59 ng/L [44-78], p < 0.001), and higher T2 (53 ms [50-56] vs. 50 ms [48-52], p < 0.001), but lower extracellular volume (55% [50-60] vs. 58% [53-61], p = 0.008) and lower indexed myocyte cell volume (48.6 g/m2 [41.1-59.8] vs. 55.7 g/m2 [47.5-68.4], p < 0.001) than patients with ATTR-CA and MVO. MVO was associated with an increased risk of mortality in the overall population (hazard ratio [HR] 1.28, 95% confidence interval [CI] 1.03-1.59, p = 0.025), and the subgroup with AL-CA (HR 1.59, 95% CI 1.17-2.17, p = 0.003) but not ATTR-CA (HR 1.04, 95% CI 0.77-1.40, p = 0.814). Microvascular obstruction is common in CA and is related to markers of amyloid infiltration. MVO is associated with an increased risk of mortality in AL-CA, but not in ATTR-CA. This reflects the intrinsic differences in disease biology between these two forms of CA, with MVO likely related to multiple myocardial processes, amyloid infiltration, oedema and myocyte death.

Een ongebruikelijke oorzaak van een hoge digestieve bloeding: amyloïdose van de maag

An unusual cause of major upper digestive bleeding: gastric amyloidosis Amyloidosis is a systemic disease that may target the gastrointestinal tract. The disease is caused by the extracellular tissue deposition of fibrils composed of low-molecular weight subunits of a variety of proteins. Amyloidosis may encompass multiple presentations and symptoms, being a challenge for both the diagnosis and the treatment. Gastrointestinal amyloidosis can cause bleeding, malabsorption, protein-losing enteropathy and dysmotility. The authors describe the case of a 71-year-old patient with persisting epigastric discomfort. The initial gastroscopy revealed ulcerative gastritis. Biopsies turned out to be Helicobacter pylori negative. There were no signs of malignancy either. An additional gastroscopy because of discomfort confirmed ulcerative gastritis. Anatomopathological examination of new biopsies revealed amyloidosis of the stomach. Additional examinations (including an echocardiography, a PET CT scan and a colonoscopy with rectal biopsies and Congored staining) did not confirm other organs to be involved in the amyloidosis. The patient was readmitted later because of a major upper digestive bleeding due to persisting gastric ulcerations. A partial distal gastrectomy turned out to be inevitable. Anatomopathological examination of the stomach confirmed non-AA amyloidosis of the stomach. Additionally, a short overview of amyloidosis with special attention to the impact of the disease in the gastrointestinal tractus is presented.

Transthyretin Cardiac Amyloidosis: Insights into Wild-Type Variants and Familial Amyloid Cardiomyopathy

Transthyretin (TTR) cardiac amyloidosis is a progressive condition characterized by amyloid fibril deposition in the heart, leading to heart failure. This review focuses on insights into wild-type (ATTRwt) and familial (ATTRm) variants of TTR amyloidosis. The pathophysiology involves TTR tetramer destabilization, monomer misfolding, and amyloid fibril formation. Therapeutic advances, including TTR stabilizers like tafamidis and Diflunisal, and gene-silencing agents such as patisiran and inotersen, show promise in managing the disease. Despite these advancements, early diagnosis remains challenging, and side effects of current therapies necessitate the development of safer, more effective treatments. Future research should focus on novel therapies, improved diagnostic methods, and personalized treatment strategies to enhance patient outcomes. This review underscores the importance of continued innovation and collaboration in tackling TTR cardiac amyloidosis.

Tumefactive Pulmonary amyloidosis in an elderly male: A Diagnostic Dilemma

Abstract Introduction/Objective Tumefactive pulmonary amyloidosis is a rare variant of pulmonary amyloidosis characterized by the extracellular deposition of abnormal protein fibrils in the lung parenchyma, forming tumor-like masses called amyloidomas. Although most cases are clinically silent, it may present with findings that mimic a wide range of respiratory conditions (eg. primary or metastatic malignant nodules, granulomatous disease, multiple pulmonary hamartomas etc), thereby necessitating a comprehensive and broad-based approach to differential diagnosis. Methods/Case Report We present a case of an 88-year-old male with a history of smoking and multiple comorbidities. He presented with numerous bilateral pulmonary nodules identified on a CT scan, concerning for malignancy. A biopsy from a left upper lobe lesion revealed necrotic tissue and was non-diagnostic. A PET scan to assess for metastatic disease was unremarkable, and demonstrated mild hypermetabolic activity, confined to the lungs, with standardized uptake values (SUV) ranging from 4.3 to a maximum SUV of 8.9. A subsequent right lung biopsy was positive for amyloid, confirmed by Congo red staining. A Mass spectrometry analysis further identified the amyloid as AL type. Serum, and urine protein electrophoresis with immunofixation were negative for M protein and the serum free light chain assay was normal as well. Significantly, the bone marrow biopsy also yielded normal results, and the patient was diagnosed with a localized form of AL amyloidosis. Results (if a Case Study enter NA) NA Conclusion This case highlights how tumefactive pulmonary amyloidosis poses a diagnostic challenge due to its rarity and resemblance to malignancy on imaging. Careful histopathological examination, including immunohistochemical stains and amyloid typing, was pivotal in establishing the correct diagnosis and underscores the essential role of pathology and laboratory medicine in differentiating rare pulmonary conditions, along with the need for a multidisciplinary approach in complex diagnostic scenarios.

Destabilisation of Alzheimer's amyloid-β protofibrils by Baicalein: mechanistic insights from all-atom molecular dynamics simulations.

Alzheimer's disease (AD) is the most common form of dementia and the fifth leading cause of death globally. Aggregation and deposition of neurotoxic Aβ fibrils in the neural tissues of the brain is a key hallmark in AD pathogenesis. Destabilisation studies of the amyloid-peptide by various natural molecules are highly relevant due to their neuroprotective and therapeutic potential for AD. We performed molecular dynamics (MD) simulation to investigate the destabilisation mechanism of amyloidogenic protofilament intermediate by Baicalein (BCL), a naturally occurring flavonoid. We found that the BCL molecule formed strong hydrophobic contacts with non-polar residues, specifically F19, A21, V24, and I32 of Chain A and B of the pentameric protofibril. Upon binding, it competed with the native hydrophobic contacts of the Aβ protein. BCL loosened the tight packing of the hydrophobic core by disrupting the hydrogen bonds and the prominent D23-K28 inter-chain salt bridges of the protofibril. The decrease in the structural stability of Aβ protofibrils was confirmed by the increased RMSD, radius of gyration, solvent accessible surface area (SASA), and reduced β-sheet content. PCA indicated that the presence of the BCL molecule intensified protofibril motions, particularly affecting residues in Chain A and B regions. Our findings propose that BCL would be a potent destabiliser of Aβ protofilament, and may be considered as a therapeutic agent in treating AD.

ATTRv-V30M amyloid fibrils from heart and nerves exhibit structural homogeneity.

Amyloidogenic transthyretin (ATTR) amyloidosis is a systemic disease characterized by the deposition of amyloid fibrils made of transthyretin. Transthyretin is primarily produced in tetrameric form by the liver, but also by retinal epithelium and choroid plexus. The deposition of these fibrils in the myocardium and peripheral nerves causes cardiomyopathies and neuropathies, respectively. Using cryoelectron microscopy (cryo-EM), we investigated fibrils extracted from cardiac and nerve tissues of an ATTRv-V30M patient. We found consistent fibril structures from both tissues, similar to cardiac fibrils previously described, but different from vitreous humor fibrils of the same genotype. Our findings, along with previous ATTR fibrils structural studies, suggest a uniform fibrillar architecture across different tissues when transthyretin originates from the liver. This study advances our understanding of how deposition and production sites influence fibril structure in ATTRv-V30M amyloidosis.

Clinical and biochemical characterization of asymptomatic carriers and symptomatic patients with hereditary transthyretin amyloidosis caused by TTR V30L mutation.

Hereditary transthyretin amyloidosis (ATTR) is an autosomal dominant disease characterized by amyloid fibril deposition. The TTR c.148G > T mutation (V30L) in ATTR is rarely reported, and its biochemical properties are unknown. Seven patients and two asymptomatic carriers from two unrelated families diagnosed with V30L variant of ATTR were included. Data on clinical manifestations, laboratory examination, electrophysiology, ophthalmological corneal confocal microscopy (CCM), pathology and molecular biological experiments was collected and analyzed. Most patients initially experienced paresthesia, with varying degrees of peripheral neuropathy, autonomic dysfunction, and cardiac involvement. Nerve conduction studies showed extensive motor and sensory nerve involvement in upper and lower limbs. CCM revealed reduced corneal nerve density and fiber length. Sural nerve biopsies indicated loss of myelinated nerve fibers, with neurogenic patterns in gastrocnemius muscle biopsies. Asymptomatic carriers had nearly normal electrophysiology but mild reductions in corneal nerve fiber density and length. Sural nerve biopsies in carriers showed mild reductions in small myelinated nerve fibers. V30L mutation impaired thermodynamic and kinetic stability of the mutant protein. Plasma TTR tetramer concentration was lower in ATTR V30L patients compared to healthy donors. Small molecule stabilizers failed to exhibit satisfactory inhibition on fibril formation of V30L mutation in vitro. This study highlights the multisystem involvement in ATTR V30L patients, including neuropathy and cardiac issues. Both patients and carriers showed abnormalities in nerve conduction, corneal microscopy, and pathology. The V30L mutation impaired protein stability and reduced plasma TTR tetramer levels. Small molecule stabilizers were ineffective, indicating a need for alternative treatments.

HGA Triggers SAA Aggregation and Accelerates Fibril Formation in the C20/A4 Alkaptonuria Cell Model.

Alkaptonuria (AKU) is a rare autosomal recessive metabolic disorder caused by mutations in the homogentisate 1,2-dioxygenase (HGD) gene, leading to the accumulation of homogentisic acid (HGA), causing severe inflammatory conditions. Recently, the presence of serum amyloid A (SAA) has been reported in AKU tissues, classifying AKU as novel secondary amyloidosis; AA amyloidosis is characterized by the extracellular tissue deposition of fibrils composed of fragments of SAA. AA amyloidosis may complicate several chronic inflammatory conditions, like rheumatoid arthritis, ankylosing spondylitis, inflammatory bowel disease, chronic infections, neoplasms, etc. Treatments of AA amyloidosis relieve inflammatory disorders by reducing SAA concentrations; however, no definitive therapy is currently available. SAA regulation is a crucial step to improve AA secondary amyloidosis treatments. Here, applying a comprehensive in vitro and in silico approach, we provided evidence that HGA is a disruptor modulator of SAA, able to enhance its polymerization, fibril formation, and aggregation upon SAA/SAP colocalization. In silico studies deeply dissected the SAA misfolding molecular pathway and SAA/HGA binding, suggesting novel molecular insights about it. Our results could represent an important starting point for identifying novel therapeutic strategies in AKU and AA secondary amyloidosis-related diseases.

Management Targeted Genetic Evaluation of an Idiopathic Neuropathy Cohort Through ATTRv Amyloidosis Screening.

While the reported prevalence of polyneuropathies is 1%-3%, the incidence of hereditary transthyretin amyloidosis in the United States is estimated to be 1 in 100 000 individuals. Polyneuropathies are known to be difficult to treat and lead to significant morbidity. The aim of pain management is symptomatic treatment, with varying approaches to progression prevention being based on the causative pathophysiology.We assessed the prevalence of hereditary amyloid transthyretin variant (ATTRv) amyloidosis, a progressive autosomal dominant multisystem disease caused by the abnormal formation and extracellular deposition of transthyretin protein fibrils in various tissues, in an idiopathic polyneuropathy population by using genetic analysis. Individuals aged 18 and over with an established diagnosis of polyneuropathy, via electromyography testing that was deemed to be idiopathic, at a large, urban neurology clinic consented to an institutional review board-approved protocol for genetic testing. No further exclusions were made regarding age of onset, family history, axonal neuropathy subtype, comorbidities suggestive of ATTRv amyloidosis, etc. Clinical genetic testing was performed on 134 participants via an 81-gene panel associated with inherited neuromuscular disorders or targeted TTR gene sequencing with deletion and duplication analysis. Within our cohort, 38.06% had at least one reportable finding in one of 38 distinct genes, for a total of 76 reported alterations. Four individuals were identified as having a single pathogenic alteration in an autosomal recessive gene, consistent with carrier status for the 4 following disorders: congenital insensitivity to pain with anhidrosis (NTRK1), Charcot-Marie-Tooth disease type IIP (LRSAM1), Brown-Vialetto-Van Laere syndrome type II (SLC52A2), hereditary sensory and autonomic neuropathy type III (IKBKAP). One individual was found to have a variant of uncertain significance (VUS) (p.G103D) in the TTR gene. Precision medicine on the molecular level with genetic testing in the identification of specific neuropathies may provide clinicians with more detailed information for developing a more direct therapeutic and treatment modality for better-targeted management. Further investigation is needed to expand on the knowledge and understanding of the clinical relevance surrounding the alterations found in the genetic evaluation of idiopathic neuropathy.

Epidemiological Changes in Transthyretin Cardiac Amyloidosis: Evidence from In Vivo Data and Autoptic Series.

Cardiac amyloidosis is an infiltrative disease that causes progressive myocardial impairment secondary to amyloid fibril deposition in the extracellular space of the myocardium. Many amyloid precursors, including transthyretin protein, are known to determine cardiac damage by aggregating and precipitating in cardiac tissue. Transthyretin cardiac amyloidosis may be either caused by rare genetic mutations of the transthyretin gene in the hereditary variant, or may arise as a consequence of age-related mechanisms in the acquired form. Although it has been labeled as a rare disease, in recent years, transthyretin cardiac amyloidosis has stood out as an emerging cause of aortic stenosis, unexplained left ventricular hypertrophy and heart failure with preserved ejection fraction, particularly in the elderly. Indeed, the integration of data deriving from both in vivo imaging techniques (whose advancement in the last years has allowed to achieve an easier and more accessible non-invasive diagnosis) and forensic studies (showing a prevalence of amyloid deposition in cardiac tissue of elderly patients up to 29%) suggests that cardiac amyloidosis is a more common disease than traditionally considered. Thanks to all the improvements in non-invasive diagnostic techniques, along with the development of efficacious therapies offering improvements in survival rates, transthyretin cardiac amyloidosis has been transformed from an incurable and infrequent condition to a relatively more diffuse and treatable disease, which physicians should take into consideration in the differential diagnostic processes in daily clinical practice.

IAPP - oligomerisation levels in plasma of people with type 2 diabetes

Islet amyloid polypeptide (IAPP) is co-secreted with insulin from pancreatic ß-cells. Its oligomerisation is regarded as disease driving force in type 2 diabetes (T2D) pathology. Up to now, IAPP oligomers have been detected in affected tissues. IAPP oligomer concentrations in blood have not been analysed so far. Using the IAPP single-oligomer-sensitive and monomer-insensitive surface-based fluorescence intensity distribution analysis (sFIDA) technology, levels of IAPP oligomers in blood plasma from healthy controls and people with T2D in different disease stages where determined. Subsequently, the level of IAPP oligomerisation was introduced as the ratio between the IAPP oligomers determined with sFIDA and the total IAPP concentration determined with ELISA. Highest oligomerisation levels were detected in plasma of people with T2D without late complication and without insulin therapy. Their levels stand out significantly from the control group. Healthy controls presented with the lowest oligomerisation levels in plasma. In people with T2D without complications, IAPP oligomerisation levels correlated with disease duration. The results clearly demonstrate that IAPP oligomerisation in insulin-naïve patients correlates with duration of T2D. Although a correlation per se does not identify, which is cause and what is consequence, this result supports the hypothesis that IAPP aggregation is the driving factor of T2D development and progression. The alternative and conventional hypothesis explains development of T2D with increasing insulin resistance causing exhaustion of pancreatic ß-cells due to over-secretion of insulin, and thus IAPP, too, resulting in subsequent IAPP aggregation and fibril deposition in the pancreas. Further experiments and comparative analyses with primary tissues are warranted.

CKD-497 inhibits NF-kB signaling and ameliorates inflammation and pulmonary fibrosis in ovalbumin-induced asthma and particulate matter-induced airway inflammatory diseases.

Introduction: Air pollution, allergens, and bacterial infections are major contributors to pathological respiratory disorders worldwide. CKD-497, derived from the rhizome of Atractylodes japonica and the fruits of Schisandra chinensis, is known for its ability to relieve cough and facilitate phlegm expectoration. However, its protective action against allergic asthma and fine dust-induced lung inflammation, along with its underlying mechanisms, have not been thoroughly investigated. Methods: In this study, we established mouse models of ovalbumin (OVA)-induced asthma and particulate matter (PM)-induced pulmonary inflammation to evaluate the effects of CKD-497. Mice were administered CKD-497 orally, and various parameters such as airway inflammation, mucus production, and proinflammatory cytokine levels (IL-1β, IL-6, TNF-α) were measured. Additionally, the macrophage cell line RAW264.7 was pretreated with CKD-497 and stimulated with lipopolysaccharide (LPS) to assess inflammation via the NF-kB signaling pathway. Results: Oral administration of CKD-497 effectively attenuated airway inflammation and mucus production in both OVA-induced asthma and PM-induced lung inflammation models. It also significantly decreased the production of proinflammatory cytokines IL-1β, IL-6, and TNF-α. CKD-497 alleviated leukocyte infiltration, including neutrophils, and reduced fibrillary collagen deposition in PM10-treated mice. In vitro, CKD-497 pretreatment inhibited LPS-induced inflammation in RAW264.7 cells through the suppression of the NF-kB signaling pathway. Discussion: CKD-497 shows potent anti-inflammatory effects in mouse models of asthma and PM-induced lung inflammation, potentially mediated by the inhibition of the NF-kB pathway. These findings suggest that CKD-497 could serve as a functional supplement to protect against respiratory diseases by mitigating pulmonary and airway inflammation induced by allergens and air pollution.

Epidemiology, diagnosis, and management of cardiac amyloidosis.

Cardiac amyloidosis (CA) is an infiltrative restrictive cardiomyopathy caused by the deposition of amyloid fibrils in the myocardium. It manifests in two primary subtypes: transthyretin cardiac amyloidosis (ATTR) and immunoglobulin light chain cardiac amyloidosis (AL). ATTR is further classified into wild-type and hereditary based on transthyretin gene mutation. Advances in diagnostics and therapeutics have transformed CA from a rare and untreatable condition to a more prevalent and manageable disease. Noninvasive diagnostic tools such as electrocardiography, echocardiography, and cardiac magnetic resonance can raise suspicion for CA; bone scintigraphy can non-invasively confirm ATTR, while AL necessitates histological confirmation. The severity of ATTR and AL can be assessed through serum biomarker-based staging. Treatment approaches differ, ranging from silencing or stabilizing transthyretin and degrading amyloid fibrils in ATTR to employing anti-plasma cell therapies and autologous stem cell transplantation in AL.

Myocardial Mechanics and Valvular and Vascular Abnormalities in Cardiac Amyloidosis.

Cardiac amyloidosis is an infiltrative disease primarily caused by extracellular tissue deposition of amyloid fibrils in the myocardial interstitium. The aim of the present review was to summarize findings regarding changes in myocardial mechanics, valvular abnormalities, and vascular remodeling detected in patients with cardiac amyloidosis.

Temporal implementation of a regional referral pathway in transthyretin cardiac amyloidosis: Emilia-Romagna experience.

Transthyretin cardiac amyloidosis (ATTR-CA) is a rare and progressive cardiomyopathy caused by amyloid fibril deposition in myocardial tissue. Diagnostic challenges have historically hampered timely detection. Recent advances in noninvasive diagnostic techniques have facilitated ATTR-CA diagnosis. We aimed to examine the development of a regional network for the diagnosis and management of ATTR-CA and describe a cohort of patients with ATTR-CA, investigate diagnostic pathways and assess clinical outcomes according to diagnosis periods. We performed a survey study analyzing answers from 11 cardiology centers and we conducted a retrospective study including patients with ATTR-CA attending a referral center between 1 January 2012 and 31 December 2022, and categorized by the period of diagnosis (2012-2016 and 2017-2022). Over the years, a growing number of patients reached a diagnosis and were treated in the surveyed nonreferral centers of the region. The retrospective study showed a more significant diagnostic delay in the earlier period rather than the later one [13.4 (5-30.2) vs. 10.6 (5.0-17.9) months, P = 0.04]. Patients diagnosed after 2017 showed a greater survival rate than those diagnosed earlier ( P = 0.02). In the multivariate analysis, the year of diagnosis from 2017 remained independently associated with mortality [hazard ratio (HR) 0.46, 95% confidence interval (CI) 0.28-0.79; P = 0.005]. This study emphasized the shift toward noninvasive diagnostic criteria. It revealed a positive impact on patient survival and disease management with the use of disease-modifying therapies and diagnostic developments in more recent years. The findings underscore the importance of disease awareness and networking to reduce diagnostic delays and enhance patient journeys for ATTR-CA.

Effect of dynamic exclusion and the use of FAIMS, DIA and MALDI-mass spectrometry imaging with ion mobility on amyloid protein identification

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.