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Journal of the National Comprehensive... Jan 2023Immunoglobulin light chain (AL) amyloidosis is a clonal plasma cell disorder with multiple clinical presentations. The diagnosis of AL amyloidosis requires a high index... (Review)
Review
Immunoglobulin light chain (AL) amyloidosis is a clonal plasma cell disorder with multiple clinical presentations. The diagnosis of AL amyloidosis requires a high index of suspicion, making a delay in diagnosis common, which contributes to the high early mortality seen in this disease. Establishing the diagnosis of AL amyloidosis requires the demonstration of tissue deposition of amyloid fibrils. A bone marrow biopsy and fat pad aspirate performed concurrently have a high sensitivity for the diagnosis of AL amyloidosis and negate the need for organ biopsies in most patients. An accurate diagnosis requires amyloid typing via additional testing, including tissue mass spectrometry. Prognostication for AL amyloidosis is largely driven by the organs impacted. Cardiac involvement represents the single most important prognostic marker, and the existing staging systems are driven by cardiac biomarkers. Apart from organ involvement, plasma cell percentage on the bone marrow biopsy, specific fluorescence in situ hybridization findings, age at diagnosis, and performance status are important prognostic markers. This review elaborates on the diagnostic testing and prognostication for patients with newly diagnosed AL amyloidosis.
Topics: Humans; Immunoglobulin Light-chain Amyloidosis; Amyloidosis; In Situ Hybridization, Fluorescence; Plasma Cells; Risk Assessment
PubMed: 36630897
DOI: 10.6004/jnccn.2022.7077 -
Genes Jun 2021The term amyloidosis describes a group of rare diseases caused by protein conformation abnormalities resulting in extracellular deposition and accumulation of insoluble... (Review)
Review
The term amyloidosis describes a group of rare diseases caused by protein conformation abnormalities resulting in extracellular deposition and accumulation of insoluble fibrillar aggregates. So far, 36 amyloid precursor proteins have been identified, and each one is responsible for a specific disease entity. Transthyretin amyloidosis (ATTRv) is one of the most common forms of systemic and ocular amyloidosis, due to the deposition of transthyretin (TTR), which is a transport protein mainly synthesized in the liver but also in the retinal pigment epithelial cells. ATTRv amyloidosis may be misdiagnosed with several other conditions, resulting in a significant diagnostic delay. Gelsolin and keratoepithelin are other proteins that, when mutated, are responsible for a systemic amyloid disease with significant ocular manifestations that not infrequently appear before systemic involvement. The main signs of ocular amyloid deposition are in the cornea, irido-corneal angle and vitreous, causing complications related to vasculopathy and neuropathy at the local level. This review aims at describing the main biochemical, histopathological and clinical features of systemic amyloidosis associated with eye involvement, with particular emphasis on the inherited forms. We discuss currently available treatments, focusing on ocular involvement and specific ophthalmologic management and highlighting the importance of a prompt treatment for the potential sight-threatening complications derived from amyloid deposition in ocular tissues.
Topics: Amyloid Neuropathies, Familial; Amyloidosis, Familial; Extracellular Matrix Proteins; Eye Diseases; Gelsolin; Genetic Predisposition to Disease; Humans; Prealbumin; Retinal Pigment Epithelium; Transforming Growth Factor beta
PubMed: 34206500
DOI: 10.3390/genes12070955 -
JACC. Cardiovascular Imaging Nov 2019Cardiac involvement drives prognosis and treatment choices in cardiac amyloidosis. Echocardiography is the first-line examination for patients presenting with heart... (Review)
Review
Cardiac involvement drives prognosis and treatment choices in cardiac amyloidosis. Echocardiography is the first-line examination for patients presenting with heart failure, and it is the imaging modality that most often raises the suspicion of cardiac amyloidosis. Echocardiography can provide an assessment of the likelihood of cardiac amyloid infiltration versus other hypertrophic phenocopies and can assess the severity of cardiac involvement. Visualizing myocardial amyloid infiltration is challenging and, until recently, was restricted to the domain of the pathologist. Two tests are transforming this: cardiac magnetic resonance (CMR) imaging and bone scintigraphy. After the administration of contrast, CMR is highly sensitive and specific for the 2 main types of ventricular myocardial amyloidosis, light chain amyloidosis (AL) and transthyretin amyloidosis (ATTR). CMR structural and functional assessment combined with tissue characterization can redefine cardiac involvement by tracking different disease processes, ranging from amyloid infiltration, to the myocardial response associated with amyloid deposition, through the visualization and quantification of myocardial edema and myocyte response. Bone scintigraphy (paired with exclusion of serum free light chains) is emerging as the technique of choice for distinguishing ATTR from light chain cardiac amyloidosis and other cardiomyopathies; it has transformed the diagnostic pathway for ATTR, allowing noninvasive diagnosis of ATTR without the need for a tissue biopsy in the majority of patients. CMR with tissue characterization and bone scintigraphy are rewriting disease understanding, classification, and definition, and leading to a change in patient care.
Topics: Amyloid Neuropathies, Familial; Cardiomyopathies; Diagnosis, Differential; Extracellular Space; Fibrosis; Humans; Immunoglobulin Light-chain Amyloidosis; Magnetic Resonance Imaging; Myocardium; Predictive Value of Tests; Radionuclide Imaging; Reproducibility of Results; Ventricular Remodeling
PubMed: 31422120
DOI: 10.1016/j.jcmg.2019.06.023 -
Journal of Alzheimer's Disease : JAD 2020The progressive aging of the population will dramatically increase the burden of dementia related to Alzheimer's disease (AD) and other neurodegenerative disorders in... (Review)
Review
BACKGROUND
The progressive aging of the population will dramatically increase the burden of dementia related to Alzheimer's disease (AD) and other neurodegenerative disorders in the future. Because of the absence of drugs that can modify the neuropathological substrate of AD, research is focusing on the application of preemptive and disease-modifying strategies in the pre-symptomatic period of the disease. In this perspective, the identification of people with cognitive frailty (CF), i.e., those individuals with higher risk of developing dementia, on solid pathophysiological bases and with clear operational clinical criteria is of paramount importance.
OBJECTIVE/METHODS
This hypothesis paper reviews the current definitions of CF, presents and discusses some of their limitations, and proposes a framework for updating and improving the conceptual and operational definition of the CF construct.
RESULTS
The potential for reversibility of CF should be supported by the assessment of amyloid, tau, and neuronal damage biomarkers, especially in younger patients. Physical and cognitive components of frailty should be considered as separate entities, instead of part of a single macro-phenotype. CF should not be limited to the geriatric population, because trajectories of amyloid accumulation are supposed to start earlier than 65 years in AD. Operational criteria are needed to standardize assessment of CF.
CONCLUSION
Based on the limitations of current CF definitions, we propose a revised one according to a multidimensional subtyping. This new definition might help stratifying CF patients for future trials to explore new lifestyle interventions or disease-modifying pharmacological strategies for AD and dementia.
Topics: Aging; Alzheimer Disease; Amyloidosis; Biomarkers; Cognition; Cognitive Dysfunction; Frailty; Humans
PubMed: 32568197
DOI: 10.3233/JAD-200137 -
Cell Reports. Medicine Nov 2023The choroid plexus (CP) plays a key role in remotely controlling brain function in health, aging, and disease. Here, we report that CP epithelial cells express the...
The choroid plexus (CP) plays a key role in remotely controlling brain function in health, aging, and disease. Here, we report that CP epithelial cells express the brain-specific cholesterol 24-hydroxylase (CYP46A1) and that its levels are decreased under different mouse and human brain conditions, including amyloidosis, aging, and SARS-CoV-2 infection. Using primary mouse CP cell cultures, we demonstrate that the enzymatic product of CYP46A1, 24(S)-hydroxycholesterol, downregulates inflammatory transcriptomic signatures within the CP, found here to be elevated across multiple neurological conditions. In vitro, the pro-inflammatory cytokine tumor necrosis factor α (TNF-α) downregulates CYP46A1 expression, while overexpression of CYP46A1 or its pharmacological activation in mouse CP organ cultures increases resilience to TNF-α. In vivo, overexpression of CYP46A1 in the CP in transgenic mice with amyloidosis is associated with better cognitive performance and decreased brain inflammation. Our findings suggest that CYP46A1 expression in the CP impacts the role of this niche as a guardian of brain immune homeostasis.
Topics: Humans; Mice; Animals; Cholesterol 24-Hydroxylase; Choroid Plexus; Tumor Necrosis Factor-alpha; Brain; Homeostasis; Mice, Transgenic; Amyloidosis
PubMed: 37944529
DOI: 10.1016/j.xcrm.2023.101278 -
Molecular Neurodegeneration Feb 2021Alzheimer's disease (AD) is among the most prevalent neurodegenerative diseases, with brain pathology defined by extracellular amyloid beta deposits and intracellular... (Review)
Review
Alzheimer's disease (AD) is among the most prevalent neurodegenerative diseases, with brain pathology defined by extracellular amyloid beta deposits and intracellular tau aggregates. To aid in research efforts to improve understanding of this disease, transgenic murine models have been developed that replicate aspects of AD pathology. Familial AD is associated with mutations in the amyloid precursor protein and in the presenilins (associated with amyloidosis); transgenic amyloid models feature one or more of these mutant genes. Recent advances in seeding methods provide a means to alter the morphology of resultant amyloid deposits and the age that pathology develops. In this review, we discuss the variety of factors that influence the seeding of amyloid beta pathology, including the source of seed, the time interval after seeding, the nature of the transgenic host, and the preparation of the seeding inoculum.
Topics: Alzheimer Disease; Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Amyloidosis; Animals; Brain; Disease Models, Animal; Humans
PubMed: 33588898
DOI: 10.1186/s13024-021-00429-4 -
Current Cardiology Reports Aug 2019We summarize key features pertaining to the two most commonly encountered types of cardiac amyloidosis (CA), monoclonal immunoglobulin light chain (AL) and transthyretin... (Review)
Review
PURPOSE OF REVIEW
We summarize key features pertaining to the two most commonly encountered types of cardiac amyloidosis (CA), monoclonal immunoglobulin light chain (AL) and transthyretin type (ATTR), expanding upon the clinical application and utility of various imaging techniques in diagnosing CA.
RECENT FINDINGS
Advances in imaging have led to earlier identification, improved diagnosis of CA and higher discriminatory power to differentiate CA from other hypertrophic phenocopies. The application of cardiac magnetic resonance imaging (CMR) has led to a deeper understanding of underlying pathophysiological processes in CA, owing largely to its intrinsic tissue characterization properties. The widespread adoption of bone scintigraphy algorithms has reduced the need for cardiac biopsy and improved diagnostic confidence in ATTR CA. As new treatments for CA are rapidly developing, there will be even greater reliance on imaging, as the requirement to diagnose disease earlier, monitor response and amend treatment strategies accordingly intensifies.
Topics: Amyloid Neuropathies, Familial; Amyloidosis; Biopsy; Cardiomyopathies; Humans; Immunoglobulin Light Chains
PubMed: 31375984
DOI: 10.1007/s11886-019-1180-2 -
International Journal of Molecular... Apr 2021Transthyretin (TTR) is an essential transporter of a thyroid hormone and a holo-retinol binding protein, found abundantly in human plasma and cerebrospinal fluid. In... (Review)
Review
Transthyretin (TTR) is an essential transporter of a thyroid hormone and a holo-retinol binding protein, found abundantly in human plasma and cerebrospinal fluid. In addition, this protein is infamous for its amyloidogenic propensity, causing various amyloidoses in humans, such as senile systemic amyloidosis, familial amyloid polyneuropathy, and familial amyloid cardiomyopathy. It has been known for over two decades that decreased stability of the native tetrameric conformation of TTR is the main cause of these diseases. Yet, mechanistic details on the amyloidogenic transformation of TTR were not clear until recent multidisciplinary investigations on various structural states of TTR. In this review, we discuss recent advancements in the structural understanding of TTR misfolding and amyloidosis processes. Special emphasis has been laid on the observations of novel structural features in various amyloidogenic species of TTR. In addition, proteolysis-induced fragmentation of TTR, a recently proposed mechanism facilitating TTR amyloidosis, has been discussed in light of its structural consequences and relevance to acknowledge the amyloidogenicity of TTR.
Topics: Amyloid; Amyloid Neuropathies, Familial; Animals; Humans; Prealbumin; Protein Folding
PubMed: 33922648
DOI: 10.3390/ijms22094429 -
Annals of Noninvasive Electrocardiology... Jul 2022Cardiac amyloidosis is a protein misfolding disorder involving deposition of amyloid fibril proteins in the heart. The associated fibrosis of the conduction tissue... (Review)
Review
BACKGROUND
Cardiac amyloidosis is a protein misfolding disorder involving deposition of amyloid fibril proteins in the heart. The associated fibrosis of the conduction tissue results in conduction abnormalities and arrhythmias. "Classical" electrocardiogram (ECG) findings in cardiac amyloidosis include that of low voltage complexes with increased left ventricular wall thickness on echocardiography. However, this "classical" finding is neither sensitive nor specific. As cardiac amyloidosis is associated with a generally poor prognosis, the need for early recognition of this disease is important given the availability of new treatment options. In this review, we highlight 3 cases of patients with cardiac amyloidosis. Although presenting with typical clinical signs and symptoms, ECG for all 3 patients was not consistent with the classical findings described. They underwent further diagnostic tests which clinched the diagnosis of cardiac amyloidosis, allowing patients to receive targeted treatment. Through the review of the literature, we will highlight the different ECG patterns in patients with different types of cardiac amyloidosis and clinical scenarios, as well as the pitfalls of using ECG to identify the condition. Lastly, we also emphasize the current paradigms in diagnosing cardiac amyloidosis through the non-invasive methods of echocardiography, cardiac magnetic resonance imaging, and nuclear technetium-pyrophosphate imaging.
CONCLUSIONS
Electrocardiogram is often the first investigation used in evaluating many cardiac disorders, including cardiac amyloidosis. However, classical features of cardiac amyloidosis on ECG are often not present. A keen understanding on the ECG features of cardiac amyloidosis and knowledge of the diagnostic workflow is important to diagnose this condition.
Topics: Amyloidosis; Cardiomyopathies; Echocardiography; Electrocardiography; Heart; Heart Diseases; Humans
PubMed: 35567784
DOI: 10.1111/anec.12967 -
BMJ Case Reports Aug 2019
Topics: Aged, 80 and over; Amyloid Neuropathies, Familial; Bone and Bones; Cardiomyopathies; Echocardiography; Heart Failure; Humans; Hypertrophy, Left Ventricular; Male; Radionuclide Imaging; Transcatheter Aortic Valve Replacement; Treatment Outcome
PubMed: 31473644
DOI: 10.1136/bcr-2019-231793