Immunoglobulin Light-Chain Amyloidosis: From Basics to New Developments in Diagnosis, Prognosis and Therapy

Amyloid fibril cytotoxicity and associated disorders

Misfolded proteins assemble into fibril structures that are called amyloids. Unlike usually folded proteins, misfolded fibrils are insoluble and deposit extracellularly or intracellularly. Misfolded proteins interrupt the function and structure of cells and cause amyloid disease. There is increasing evidence that the most pernicious species are oligomers. Misfolded proteins disrupt cell function and cause cytotoxicity by calcium imbalance, mitochondrial dysfunction, and intracellular reactive oxygen species. Despite profound impacts on health, social, and economic factors, amyloid diseases remain untreatable. To develop new therapeutics and to understand the pathological manifestations of amyloidosis, research into the origin and pathology of amyloidosis is urgently needed. This chapter describes the basic concept of amyloid disease and the function of atypical amyloid deposits in them.

Healthcare and economic burden of heart failure with amyloidosis: An insight from National Readmission Database

INTRODUCTION

We analyzed trends, causes and predictors of 30-days readmission in cardiac amyloidosis and inspected the impact of these readmissions on mortality, morbidity, and utilization of healthcare resources.

METHODS

Heart Failure with cardiac amyloidosis patients were selected from National readmission Database (NRD) using ICD-10 CM codes. Patients younger than 18 years, elective readmissions, readmissions due to trauma, patients with missing data and December 2018 admissions were excluded. Primary outcome was all-cause 30-day readmissions rate, secondary outcomes were factors associated with 30-days readmissions and their effect on morbidity, mortality, and healthcare resource utilization.

RESULTS

Out of 4123 total heart failure with cardiac amyloidosis index admissions in 2018, 3374 patients were included in final analysis. 19.6% were readmitted within 30 days. Readmitted patients were younger, sicker, admitted to small or large hospital. Hypertensive heart and Chronic Kidney Disease (CKD Stage I-IV) with Congestive Heart Failure (CHF), hypertensive heart and CKD (Stage V) or End Stage Renal Disease (ESRD) with CHF, hypertensive heart disease with CHF, acute kidney failure, and sepsis were the most common causes of readmissions. Young age, admission to small and large size hospitals were independent predictors of 30-day readmissions. Readmissions had higher mortality, costed 6.6 extra in hospital days to patients and $16380 per admission to healthcare system.

CONCLUSIONS

Cardiac amyloidosis readmissions were associated with increased morbidity and mortality of patients and extra burden on the healthcare system. There is a need to identify patients at risk for readmissions to improve patient outcomes and decrease healthcare cost.

A Comprehensive Multidisciplinary Diagnostic Algorithm for the Early and Efficient Detection of Amyloidosis

Amyloidosis is a rare protein misfolding disease caused by the accumulation of amyloid fibrils in various tissues and organs. There are different subtypes of amyloidosis, with light chain (AL) amyloidosis being the most common. Amyloidosis is notoriously difficult to diagnose because it is clinically heterogeneous, no single test is diagnostic for the disease, and diagnosis typically involves multiple specialists. Here, we propose an integrated, multidisciplinary algorithm for efficiently diagnosing amyloidosis. Drawing on research from several medical disciplines, we have combined clinical decisions and best practices into a comprehensive algorithm to facilitate the early detection of amyloidosis. Currently, many patients are diagnosed more than 6 months after symptom onset, yet early diagnosis is the major predictor of survival. Our algorithm aims to shorten the time to diagnosis with efficient sequencing of tests and minimizing uninformative investigations. We also recommend typing and staging of confirmed amyloidosis to guide treatment. By reducing time to diagnosis, our algorithm could lead to earlier and more targeted treatment, ultimately improving prognosis and survival.

Screening approaches to cardiac amyloidosis in different clinical settings: Current practice and future perspectives

Cardiac amyloidosis is a serious and progressive infiltrative disease caused by the deposition of amyloid fibrils in the heart. In the last years, a significant increase in the diagnosis rate has been observed owing to a greater awareness of its broad clinical presentation. Cardiac amyloidosis is frequently associated to specific clinical and instrumental features, so called "red flags", and it appears to occur more commonly in particular clinical settings such as multidistrict orthopedic conditions, aortic valve stenosis, heart failure with preserved or mildly reduced ejection fraction, arrhythmias, plasma cell disorders. Multimodality approach and new developed techniques such PET fluorine tracers or artificial intelligence may contribute to strike up extensive screening programs for an early recognition of the disease.

AL Amyloidosis for Cardiologists: Awareness, Diagnosis, and Future Prospects: JACC: CardioOncology State-of-the-Art Review

Amyloid light chain (AL) amyloidosis is a rare, debilitating, often fatal disease. Symptoms of cardiomyopathy are common presenting features, and patients often are referred to cardiologists. Cardiac amyloid infiltration is the leading predictor of death. However, the variable presentation and perceived rarity of the disease frequently lead to delay in suspecting amyloidosis as a cause of heart failure, leading to misdiagnoses and a marked delay in diagnosis, with devastating consequences for the patient. A median time from symptom onset to correct diagnosis of about 2 years is often too long when median survival from diagnosis for patients with AL amyloidosis and cardiomyopathy is 4 months to 2 years. The authors highlight the challenges to diagnosis, identify gaps in the current knowledge, and summarize novel treatments on the horizon to raise awareness about the critical need for early recognition of symptoms and diagnosis of AL amyloidosis aimed at accelerating treatment and improving outcomes for patients.

Cardiac Amyloidosis with Normal Wall Thickness: Prevalence, Clinical Characteristics and Outcome in a Retrospective Analysis

Background: Cardiac amyloidosis (CA) is a rare, progressive, infiltrative cardiac disease. Light chain (AL) and transthyretin (ATTR) amyloidosis are in the background in almost all cases. New, easily available diagnostic tools and recently introduced novel therapies for both types of CA put this disease into the field of interest. Increased left ventricular wall thickness (IWT) detected by echocardiography is generally thought to be a necessary part of the diagnosis. We aimed to determine the proportion of CA patients without IWT, and to define the clinical characteristics of this cohort. Methods: In an academic tertiary center for CA, we identified patients diagnosed and treated for CA between January 2009 and February 2022. In a retrospective analysis we defined the proportion of patients with (≥12 mm) and without (<12 mm) IWT, and described their clinical features. Results: We identified 98 patients suitable for the analysis. In total, 70 had AL and 27 ATTR CA; 89 patients had CA with IWT and 9 patients (9%) had CA without IWT. All non-IWT patients had AL type CA. Both group of patients had clinically significant disease, which is supported by the relevant elevation in cardiac biomarker levels. There was no difference between the outcome of the two groups. Conclusion: Patients without IWT form a relevant subgroup among those with CA. Our results suggest that diagnostic algorithms and criteria should take these individuals into consideration, and, therefore, give them access to effective treatments.

Case Report: AL Amyloidosis Severe Restrictive Cardiomyopathy Associated With Multiple Myeloma—Diagnostic Difficulties

Background

Cardiac AL amyloidosis as a complication of multiple myeloma (MM) is a formidable life-threatening condition. The first-line therapy for both MM and systemic AL amyloidosis is proteasome inhibitors (PIs). Unfortunately, the use of PIs may lead to cardiovascular toxicity development, which requires specific cardio-oncology supervision.

Case Report

A 57-year-old woman was admitted to a university hospital with clinical manifestation of progressive chronic heart failure. The patient had hypertension and no history of diabetes mellitus, myocardial infarction (MI), stroke, and arrhythmias. After a series of laboratory and instrumental examination methods, MM complicated by cardiac AL amyloidosis was proved. Upon specific cardio-oncology examination (NT-proBNP 4,274 pg/ml), ECHO showed systolic dysfunction, motion abnormalities in LV basal and middle segments, and a typical depositional myocardium pattern (“luminescence”); cardiac MRI revealed restrictive cardiomyopathy and specific hyperenhancement of the ventricles and atria; 24-h ECG showed QS-pattern in leads V1–V3 and unstable ventricular tachycardia (VT) paroxysms. Cardio-oncology consultation showed baseline cardiovascular risk was very high (≥20%), and cardioprotective therapy [iACE/ARBs, beta-blockers (BB), statins] was administered. The patient underwent VCD (bortezomib; cyclophosphamide; dexamethasone) chemotherapy (CMT) program. By the time of publication, the patient had received four CMT courses with a positive oncohematological and cardiovascular effect.

Conclusion

In this clinical case, we described a complication of MM, which was rare according to the severity and manifestation with restrictive cardiomyopathy due to secondary cardiac amyloidosis. The case's features were difficulties in verifying the underlying disease and its own complication, and the complexity of patient management according to modern principles of cardio-oncology.

Treatment of Transthyretin Amyloid Cardiomyopathy: The Current Options, the Future, and the Challenges

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressively debilitating, rare disease associated with high mortality. ATTR-CM occurs when TTR amyloid protein builds up in the myocardium along with different organs, most commonly the peripheral and the autonomic nervous systems. Managing the cardiac complications with standard heart failure medications is difficult due to the challenge to maintain a balance between the high filling pressure associated with restricted ventricular volume and the low cardiac output. To date, tafamidis is the only agent approved for ATTR-CM treatment. Besides, several agents, including green tea, tolcapone, and diflunisal, are used off-label in ATTR-CM patients. Novel therapies using RNA interference also offer clinical promise. Patisiran and inotersen are currently approved for ATTR-polyneuropathy of hereditary origin and are under investigation for ATTR-CM. Monoclonal antibodies in the early development phases carry hope for amyloid deposit clearance. Despite several drug candidates in the clinical development pipeline, the small ATTR-CM patient population raises several challenges. This review describes current and future therapies for ATTR-CM and sheds light on the clinical development hurdles facing them.

Clinical Clues and Diagnostic Workup of Cardiac Amyloidosis

Cardiac amyloidosis is increasingly recognized as an underlying cause of left ventricular wall thickening, heart failure, and arrhythmia with variable clinical presentation. Due to the subtle cardiac findings in early transthyretin cardiac amyloidosis and the availability of therapies that can modify but not reverse the disease progression, early recognition is vital. In light chain amyloidosis, timely diagnosis and treatment can significantly improve survival. In this manuscript, we review the clinical, imaging, and electrocardiographic clues that should raise suspicion for cardiac amyloidosis and provide a simplified diagnostic workup algorithm that ensures an accurate diagnosis. The evolution of the noninvasive diagnosis of cardiac amyloidosis has significantly influenced our understanding of disease prevalence, presentations, and outcomes. However, clinical recognition of clues and red flags remains the most important factor in advancing the care of patients with cardiac amyloidosis.

Fixed duration vs. prolonged duration treatment after first line therapy in patients with systemic light chain amyloidosis

BACKGROUND

The main objective of treatment in systemic light chain amyloidosis (AL amyloidosis) is to achieve the best hematological response. Deeper responses are associated with better organ responses and survival. In this study, we analysed the efficacy of prolonged duration treatment after first line in patients with AL amyloidosis.

METHODS

Retrospective analysis that included patients older than 18 years with AL amyloidosis. We excluded patients with more than 30% marrow plasmacytosis or concurrent multiple myeloma. Two cohorts identified accordingly if they received or not prolonged treatment after the first line. Survival analysis regarding progression free survival (PFS) and overall survival (OS) estimated with Kaplan-Meier and comparisons between groups with log-rank.

RESULTS

Thirty-eight patients were included in the analysis with a median age of 55 years. Twenty-one patients received prolonged duration treatment and 17 did not. In the prolonged duration group, after a median duration of 12 months, the median PFS was 58.8 months. In the fixed duration treatment group, PFS was 30.6 months. The difference was significant with p = .0045 favouring prolonged duration treatment. Organ response was sustained for a longer period in the prolonged duration treatment group. For OS, the difference was not significant.

CONCLUSIONS

Prolonged duration treatment in patients with systemic light chain amyloidosis correlated with better PFS and deeper organ responses. Prospective studies are needed to analyse this further.

Physiology, Diagnosis and Treatment of Cardiac Light Chain Amyloidosis

AL (light-chain) amyloidosis is a systemic disease in which amyloid fibers are formed from kappa or lambda immunoglobulin light chains, or fragments thereof, produced by a neoplastic clone of plasmocytes. The produced protein is deposited in tissues and organs in the form of extracellular deposits, which leads to impairment of their functions and, consequently, to death. Despite the development of research on pathogenesis and therapy, the mortality rate of patients with late diagnosed amyloidosis is 30%. The diagnosis is delayed due to the complex clinical picture and the slow progression of the disease. This is the type of amyloidosis that most often contributes to cardiac lesions and causes cardiac amyloidosis (CA). Early diagnosis and correct identification of the type of amyloid plays a crucial role in the planning and effectiveness of therapy. In addition to standard histological studies based on Congo red staining, diagnostics are enriched by tests to determine the degree of cardiac involvement. In this paper, we discuss current diagnostic methods used in cardiac light chain amyloidosis and the latest therapies that contribute to an improved patient prognosis.

Renal Amyloidosis: A Clinicopathological Study From a Tertiary Care Hospital in Pakistan

Introduction

Systemic amyloidosis can affect any organ in the body, but the kidney is the most commonly involved site. It is characterized by the extracellular deposition of insoluble fibrillar proteins. Amyloid deposits can be identified histologically by Congo red stain, which gives apple-green birefringence under polarized light. Typing of renal amyloidosis is done by direct immunofluorescence on frozen tissue. The most common types of amyloidosis seen in renal tissue are amyloid light chain (AL) primary amyloidosis and amyloid A (AA) secondary amyloidosis. Although primary amyloidosis is considered the most common type in western countries, however, in the subcontinent region, secondary amyloidosis is more common.

The spectrum of signs and symptoms in renal amyloidosis is variable including isolated proteinuria, nephrotic syndrome, hypertension, hypotension, and renal insufficiency. The present study aims to evaluate the incidence and aetiology of various types of renal amyloidosis, determine their distribution within the kidney, and study various clinicopathological features.

Objective

The present study aims to evaluate the aetiology and clinicopathological profile of renal amyloidosis, determine its various types, and their distribution within the kidney.

Materials and methods

This retrospective cross-sectional study was conducted from 1st January 2013 to 31st December 2020 at the Department of Histopathology, Shifa International Hospital (SIH), Islamabad. All renal biopsies diagnosed as renal amyloidosis were included in the study. Data were analysed using SPSS version 23 (IBM Corp., Armonk, NY). Frequency and percentages were calculated for qualitative variables, and mean and standard deviation were calculated for quantitative variables.

Results

A total of 131 cases were diagnosed with renal amyloidosis during the study period of eight years (from 1st January 2013 to 31st December 2020) at SIH. The age range varied from 17 to 82 years. The mean age of the patients was 45 ± 16.33 years. Out of 131 patients, 82 (62.6%) were males and 49 (37.4%) were females. Amongst them, 72 (54%) cases were diagnosed with secondary AA amyloidosis and 16 (12%) cases were diagnosed with primary AL amyloidosis. The rest of the cases 43 (34%) were of indeterminate type. The associated conditions in secondary amyloidosis were tuberculosis in 41 (57%), rheumatoid arthritis in 16 (22%), ankylosing spondylitis in five (7%), lymphoma in three (4%), diabetes in two (3%), and chronic osteomyelitis, chronic heart disease, hepatitis, and vasculitis in one case each (1.7%). Out of 16 cases reported with AL amyloidosis, 10 cases (62.5%) had a history of multiple myeloma. The most common clinical presentation was nephrotic syndrome followed by subnephrotic proteinuria, renal failure, and hypertension.

Conclusion

The findings of the present study show underlying etiological factors and clinicopathological characteristics of renal amyloidosis. AA amyloidosis is the most common type of renal amyloidosis in our study and tuberculosis is the most common aetiological factor. AL amyloidosis is less frequent in our population.

Hypovitaminosis D Is Prevalent in Patients With Renal AL Amyloidosis and Associated With Renal Outcome

INTRODUCTION

Vitamin D deficiency is common, but no data have been reported on vitamin D levels in light chain (AL) amyloidosis.

PATIENTS AND METHODS

In this exploratory study, stored serum samples from 173 patients with newly diagnosed AL amyloidosis were analyzed for vitamin studies which included 25-hydroxyvitamin D [25(OH)D], 1,25-dihydroxyvitamin D [1,25(OH)₂D] and vitamin D binding protein (DBP). Measurements were made by liquid chromatography-tandem mass spectrometry. Kidney survival and overall survival (OS) were assessed in association to vitamin D status.

RESULTS

Cardiac and kidney involvement occurred in 69% and 63% of patients, respectively. 25(OH)D deficiency (<20 ng/mL) was seen in 56.6% of the patients and was notably found among patients with heavy proteinuria (96%), hypoalbuminemia (84.3%) and morbidly obese patients (68.3%). Heavy proteinuria (>5 gr/24-h) and vitamin D supplementation were independent predictors of 25(OH)D level on nominal multivariate regression analysis. 1,25(0H)₂D deficiency was noted in 37.6% of patients and was independently associated with low eGFR and hypoalbuminemia. Progression to ESRD occurred in 23.7% of evaluable patients. Patients who progressed to ESRD had lower serum 25(OH)D and 1,25(OH)₂D levels compared to those who did not progress to ESRD. On a multivariate analysis, severe 25(OH)D deficiency was an independent predictor of progression to ESRD as was renal stage, while 1,25(OH)₂D deficiency was not.

CONCLUSIONS

Hypovitaminosis D is common in AL amyloidosis, particularly among patients with heavy proteinuria. Severe 25(OH)D deficiency at time of diagnosis predicts progression to ESRD.

Macroglossia reveals multiple myeloma

We present an eighty-year old man with a one year history of progressive macroglossia, dysphagia and loss of weight. He had a medical history of arterial hypertension and prostatic hypertrophy which he had under good therapeutic control. The entire tongue was swollen, had hard solidity and was slightly painful upon palpation. A tongue biopsy revealed an amyloid deposition as it coloured bright orange-red on Congo Red staining and lead us subsequently to the diagnosis of amyloidosis; then a bone marrow biopsy confirmed the diagnosis of multiple myeloma. The case was further evaluated by a multidisciplinary team who considered it appropriate to start a lowdose melphalan treatment combined with supportive care. When macroglossia in the tongue is confirmed to be amyloidosis the differential diagnosis should include systemic amyloidosis deposition and multiple myeloma.

Silver Nanoparticles as a Tool for the Study of Spontaneous Aggregation of Immunoglobulin Monoclonal Free Light Chains

Some misfolded proteins, e.g., immunoglobulin monoclonal free light chains (FLC), tend to form fibrils. Protein deposits in tissue may lead to amyloidosis and dysfunction of different organs. There is currently no technique allowing for the identification of FLC that are prone to aggregate. The development of such a method would enable the early selection of patients at high risk of developing amyloidosis. The aim of this study was to investigate whether silver nanoparticles (AgNPs) could be a useful tool to study the process of aggregation of FLC and their susceptibility to form the protein deposits. Mixtures of AgNPs and urine samples from patients with multiple myeloma were prepared. To evaluate the aggregation process of nanoparticles coated with proteins, UV-visible spectroscopy, transmission electron microscopy, and the original laser light scattering method were used. It has been shown that some clones of FLC spontaneously triggered aggregation of the nanoparticles, while in the presence of others, the nanoparticle solution became hyperstable. This is probably due to the structure of the chains themselves, unique protein-AgNPs interactions and perhaps correlates with the tendency of some FLC clones to form deposits. Nanoparticle technology has proven to be helpful in identifying clones of immunoglobulin FLC that tend to aggregate.

Emerging therapy in light-chain and acquired transthyretin-related amyloidosis: an Italian single-centre experience in heart transplantation

AIMS

The prognosis for patients affected by light-chain cardiac amyloidosis and acquired transthyretin-related (TTR) amyloidosis is poor. Heart transplantation (HTx) could improve prognosis also enabling autologous stem cell transplantation (ASCT) in the first group.

METHODS AND RESULTS

A total of 36 patients affected by systemic amyloidosis have been referred to our centre from 2009 to 2019. Of these, nine had cardiac involvement: seven by light-chain amyloidosis and two by acquired TTR amyloidosis. None died while waiting for HTx. A specific internal protocol useful to select candidates and to monitor the organ involvement after HTx was developed. Median age at diagnosis was 54 years and 66% were male. The most common short-term complication after HTx was renal failure (44%), followed by acute cardiac rejection more than 2R (22%). ASCT was performed in six out of seven light-chain cardiac amyloidosis patients, with a median time of 6 months after HTx. Two patients affected by light-chain cardiac amyloidosis died due to amyloidosis relapse: one before undergoing ASCT. After a median follow-up of 31 (7-124) months, 1- and 5-year survival was 88 and 66% in the cardiac light-chain amyloidosis group. Conversely, 1- and 5-year survival was 100% in the acquired TTR amyloidosis group.

CONCLUSION

HTx may represent a valuable option in carefully selected patients. ASCT after HTx is an effective treatment that could decrease amyloidosis relapse in light-chain cardiac amyloidosis patients. A multidisciplinary approach is mandatory to select the best candidates and to obtain the most effective results with a specific surveillance follow-up protocol.

Systemic amyloidosis from A (AA) to T (ATTR): a review

Systemic amyloidosis is a rare protein misfolding and deposition disorder leading to progressive organ failure. There are over 15 types of systemic amyloidosis, each caused by a different precursor protein which promotes amyloid formation and tissue deposition. Amyloidosis can be acquired or hereditary and can affect various organs, including the heart, kidneys, liver, nerves, gastrointestinal tract, lungs, muscles, skin and soft tissues. Symptoms are usually insidious and nonspecific resulting in diagnostic delay. The field of amyloidosis has seen significant improvements over the past decade in diagnostic accuracy, prognosis prediction and management. The advent of mass spectrometry-based shotgun proteomics has revolutionized amyloid typing and has led to the discovery of new amyloid types. Accurate typing of the precursor protein is of paramount importance as the type dictates a specific management approach. In this article, we review each type of systemic amyloidosis to provide the practitioner with practical tools to improve diagnosis and management of these rare disorders.

Wild-type Transthyretin Amyloid Myopathy With an Inclusion Body Myositis Phenotype

Senile systemic amyloidosis (SSA), or wild-type transthyretin (wtATTR) amyloidosis, is associated most commonly with cardiomyopathy and carpal tunnel syndrome. SSA-associated skeletal myopathy is rare. We describe the case of a patient with SSA who exhibited asymmetric quadriceps and finger flexor weakness, a phenotype usually seen in inclusion body myositis.

Outcome of patients with severe AL amyloidosis and biopsy-proven renal involvement ineligible for bone marrow transplantation

INTRODUCTION

AL amyloidosis is caused by a clone of plasma cell. Due to the impact of the disease on patient survival, careful evaluation of organ involvement is essential and treatment should be tailored to single patient's risk.

AIM

We analyzed the clinical, laboratory and histological characteristics of 21 elderly patients (pts) (mean age 74.7 ± 7.97 years, range 55-81) with AL amyloidosis, including 17 patients (81%) with biopsy-proven renal involvement, who were ineligible for bone marrow transplantation, and evaluated the impact of renal impairment on survival.

RESULTS

Cardiac and renal involvement was found in 14 (67%) cases. Among the 17 patients with renal involvement, 12 had renal failure with proteinuria, and one showed isolated renal failure and vascular amyloid deposition. Hematological response occurred in 57.1% after first line therapy (75% after three cycles). In six of the patients with renal involvement, proteinuria decreased from 4.2 to 1.1 g/24 h (range 0.2-3 g/24 h), serum Creatinina (sCr) levels declined or stabilized. Severe renal failure at diagnosis was found to directly influence patient survival, while the Staging System for Renal Outcome in AL Amyloidosis did not associate with outcomes.

CONCLUSIONS

To the best of our knowledge this is the first case series in which the whole cohort of patients with urinary or functional abnormalities underwent a histological evaluation. None of the patients were eligible for bone marrow transplantation. Hematologic response was 57.1%, while renal response was much lower (35%). Of note, the Staging System did not completely apply to this peculiar setting of patients in whom renal involvement was not presumptive but biopsy-proven. More aggressive approaches may be needed in these patients to avoid the inexorable progression of the disease.

Cardiac Care of Patients with Cardiac Amyloidosis

Cardiac amyloidosis, the majority of cases of which are due to immunoglobulin light chain amyloidosis (AL) and transthyretin amyloidosis (ATTR), affects different aspects of the heart and cardiovascular system. Amyloid-induced cardiomyopathy, clinically manifesting with heart failure and electrophysiological abnormalities, has distinct characteristics compared to non-amyloid cardiomyopathies. Accordingly, specific management strategies are required. This paper will review the cardiovascular manifestations of patients with cardiac amyloidosis and their suggested treatment strategies, emphasizing the importance of multidisciplinary care.

Diagnosing cardiac amyloidosis in every-day practice: A practical guide for the cardiologist

Cardiac amyloidosis (CA) has emerged as a previously underestimated cause of heart failure and mortality. Underdiagnosis resulted mainly from unawareness of the true disease prevalence and the non-specific symptoms of the disease. CA results from extracellular deposition of misfolded protein fibrils, commonly derived from transthyretin (ATTR) or immunoglobulin light chains (AL). A significant proportion of older patients with heart failure and other extracardiac manifestations suffer from ATTR-CA, whereas AL-CA is still considered a rare disease. This article provides an overview of CA with a special focus on current and emerging diagnostic modalities. Furthermore, we provide a diagnostic algorithm for the evaluation of patients with suspected CA in every-day practice.

Disentangling the Amyloid Pathways: A Mechanistic Approach to Etiology

Amyloids are fibrillar protein aggregates associated with diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), type II diabetes and Creutzfeldt-Jakob disease. The process of amyloid polymerization involves three pathological protein transformations; from natively folded conformation to the cross-β conformation, from biophysically soluble to insoluble, and from biologically functional to non-functional. While amyloids share a similar cross-β conformation, the biophysical transformation can either take place spontaneously via a homogeneous nucleation mechanism (HON) or catalytically on an exogenous surface via a heterogeneous nucleation mechanism (HEN). Here, we postulate that the different nucleation pathways can serve as a mechanistic basis for an etiological classification of amyloidopathies, where hereditary forms generally follow the HON pathway, while sporadic forms follow seed-induced (prions) or surface-induced (including microbially induced) HEN pathways. Critically, the conformational and biophysical amyloid transformation results in loss-of-function (LOF) of the original natively folded and soluble protein. This LOF can, at least initially, be the mechanism of amyloid toxicity even before amyloid accumulation reaches toxic levels. By highlighting the important role of non-protein species in amyloid formation and LOF mechanisms of toxicity, we propose a generalized mechanistic framework that could help better understand the diverse etiology of amyloid diseases and offer new opportunities for therapeutic interventions, including replacement therapies.

Fundamentals of Light Chain Cardiac Amyloidosis: A Focused Review

The estimated prevalence of AL CA in the US is approximately 8-12 cases per million. Almost 30-50% diagnosed cases of AL amyloid in the US have multisystem involvement, including cardiac involvement. Even with the availability of advanced diagnostic testing and novel therapies, prognosis remains poor. It is overlooked as a cause of heart failure with preserved ejection fraction leading to a delay in diagnosis when management options are limited and associated with poor survival outcomes. Therefore, the education of physicians is needed to ensure that it would be highly considered as a differential diagnosis. The purpose of this manuscript is to review the advances in the diagnosis and management of cardiac amyloidosis with the aim of educating colleagues who provide care in the primary care setting. We have summarized the pathogenesis of amyloidosis, its association with plasma cell dyscrasias, novel diagnostic and surveillance approaches including echocardiography, cardiovascular magnetic resonance imaging, histopathologic techniques, systemic biomarkers, and advanced treatment approaches including supportive symptomatic management and standard of care chemotherapy targeting the amyloid deposits. Given the overall poor prognosis of amyloidosis, we have also discussed the role of palliative and hospice care.

Multiparametric Echocardiography Scores for the Diagnosis of Cardiac Amyloidosis

OBJECTIVES

This study aimed to investigate the accuracy of a broad range of echocardiographic variables to develop multiparametric scores to diagnose CA in patients with proven light chain (AL) amyloidosis or those with increased heart wall thickness who had amyloid was suspected. We also aimed to further characterize the structural and functional changes associated with amyloid infiltration.

BACKGROUND

Cardiac amyloidosis (CA) is a serious but increasingly treatable cause of heart failure. Diagnosis is challenging and frequently unclear at echocardiography, which remains the most often used imaging tool.

METHODS

We studied 1,187 consecutive patients evaluated at 3 referral centers for CA and analyzed morphological, functional, and strain-derived echocardiogram parameters with the aim of developing a score-based diagnostic algorithm. Cardiac amyloid burden was quantified by using extracellular volume measurements at cardiac magnetic resonance.

RESULTS

A total of 332 patients were diagnosed with AL amyloidosis and 339 patients with transthyretin CA. Concentric remodeling and strain-derived parameters displayed the best diagnostic performance. A multivariable logistic regression model incorporating relative wall thickness, E wave/e' wave ratio, longitudinal strain, and tricuspid annular plane systolic excursion had the greatest diagnostic performance in AL amyloidosis (area under the curve: 0.90; 95% confidence interval: 0.87 to 0.92), whereas the addition of septal apical-to-base ratio yielded the best diagnostic accuracy in the increased heart wall thickness group (area under the curve: 0.80; 95% confidence interval: 0.85 to 0.90).

CONCLUSIONS

Specific functional and structural parameters characterize different burdens of CA deposition with different diagnostic performances and enable the definition of 2 scores that are sensitive and specific tools with which diagnose or exclude CA.

Hiding in Plain Sight: Cardiac Amyloidosis, an Emerging Epidemic

Amyloidosis is a term used to describe a group of rare heterogeneous diseases that ultimately result in the deposition and accumulation of misfolded proteins. These misfolded proteins, known as amyloids, are associated with a variety of precursor proteins that have amyloidogenic potential. Ultimately, the specific type of amyloidosis is dependent on multiple factors including genetic variability of precursor proteins and the tissue or organ in which the amyloid accumulates. Several types of amyloid have a predilection for the heart and thus contribute to cardiac amyloidosis, a major cause of restrictive cardiomyopathy. Individuals with cardiac amyloidosis present clinically with heart failure with preserved ejection fraction. Although improved diagnostics and increased awareness of cardiac amyloidosis have led to a relative increase in diagnosis, cardiac amyloidosis remains an underrecognized and underdiagnosed cause of heart failure with preserved ejection fraction. It is essential to properly identify cases of cardiac amyloidosis and determine the pathology responsible for the formation of amyloid to appropriately provide management. This review aims to encourage physician awareness of cardiac amyloidosis by focusing on clinical presentation and the distinctions between types. Furthermore, epidemiology is central to understanding the affected demographics and sometimes hereditary nature of the disease. Improved understanding of cardiac amyloidosis will ideally lead to earlier diagnosis and interventions to improve patient outcomes.

Ten-year survivors in AL amyloidosis: characteristics and treatment pattern

Improvement in survival in Light chain (AL) amyloidosis has been seen over recent decades, enabling more patients to achieve long-term survival. Patients with AL amyloidosis who survived ≥10 years from time of diagnosis (n = 186) were the subject of this study. Ten-year survivors represented 22% of the total population. These patients were characterized by favourable patient, organ and plasma cell features. Of note, trisomies were less common among 10-year survivors compared to those who did not survive to 10 years. All-time best haematological response was complete response in 67%, very good partial response in 30%, partial response in 2% and no response in 1%, with 11% having received a consolidative strategy for inadequate response to first line therapy. The overall organ response rate to first-line therapy was 76%, which increased to 86% when considering subsequent line(s) of therapy. Forty-seven percent of the 10-year survivors did not require a second-line therapy. The median treatment-free survival (TFS) among the 10-year survivors was 10·5 years (interquartile range 7·4-12·2). On multivariate analysis independent predictors for TFS were the achievement of complete haematological response and lack of cardiac involvement. Long-term survivors are increasingly seen in AL amyloidosis and present distinct patient, organ and clonal disease features.

A Modern Primer on Light Chain Amyloidosis in 592 Patients With Mass Spectrometry-Verified Typing

OBJECTIVE

To describe the clinical and laboratory characteristics of patients with meticulously typed light chain (AL) amyloidosis.

PATIENTS AND METHODS

Patients (N=592) with biopsy-proven, mass spectrometry-confirmed AL amyloidosis diagnosed from January 1, 2008, through August 31, 2015, were included.

RESULTS

The median patient age at diagnosis was 63 years. Thirty-four percent of patients (n=204) had isolated organ involvement, mostly heart (19% [n=115]) followed by kidney (9% [n=53]). In contrast, 25% (n=146) had more than 2 involved organs. Patients with isolated cardiac involvement had similar cardiac dysfunction compared with those with nonisolated cardiac amyloidosis. In contrast, isolated renal involvement was associated with increased proteinuria and higher estimated glomerular filtration rate compared with nonisolated renal amyloidosis. Serum and urine immunofixation electrophoresis results were positive in 80% and 88% of patients, respectively, with 94% of patients having at least 1 positive immunofixation electrophoresis result (serum or urine). The serum free light chain ratio was abnormal in 91% of patients. When all monoclonal protein studies were combined, only 1 patient (0.2%) had normal results. The 1- and 5-year survival rates were 65% and 46%, respectively. Survival of patients with cardiac amyloidosis was not influenced by the number of involved organs (1 vs >1 organ), emphasizing the prognostic significance of cardiac involvement.

CONCLUSION

When mass spectrometry is used to definitively type amyloid, only a fraction of a percent of patients with AL have negative monoclonal protein studies, unlike historical reports. Patient characteristics and outcomes of accurately typed patients are described.

Haematological response and overall survival in two consecutive Dutch patient cohorts with AL amyloidosis diagnosed between 2008 and 2016

BACKGROUND

Although survival has improved in recent decades, the short-term prognosis of patients with immunoglobulin light chain (AL) amyloidosis remains grim. We aimed to assess overall survival (OS) of AL amyloidosis patients by comparing cohorts in two consecutive time periods.

METHODS

Data were collected and compared on 126 patients from two tertiary referral centres in The Netherlands during the time periods 2008-2012 and 2013-2016.

RESULTS

There was a non-significant trend to improved 6-month OS in the last cohort (78% vs. 67%, p = .216, crude odds ratio 1.66, 95%CI 0.74-3.70, adjusted odds ratio 2.22, 95%CI 0.88-5.56). Patients in this cohort had higher Mayo risk scores (stage III 40% vs. 24%, p < .001 and revised stage IV 14% vs. 11%, p < .001), higher use of bortezomib (50% vs. 30%), and better haematological response (complete response/very good partial response in 39% vs. 27%, p < .001). Diagnostic delay was similar in both time periods.

CONCLUSIONS

In the 2013-2016 cohort there was a trend toward improved 6-month OS, and an improved haematological response. Patients in this cohort had more advanced cardiac disease and received bortezomib more frequently, but diagnostic delay was similar to the 2008-2012 cohort. For further prognostic improvement, practitioners should be more alert, especially for cardiac amyloidosis.

MR neurography biomarkers to characterize peripheral neuropathy in AL amyloidosis

Objective

To detect, localize, and quantify peripheral nerve lesions in amyloid light chain (AL) amyloidosis by magnetic resonance neurography (MRN) in correlation with clinical and electrophysiologic findings.

Methods

We prospectively examined 20 patients with AL-polyneuropathy (PNP) and 25 age- and sex-matched healthy volunteers. After detailed neurologic and electrophysiologic testing, the patient group was subdivided into mild and moderate PNP. MRN in a 3.0 tesla scanner with anatomical coverage from the lumbosacral plexus and proximal thigh down to the tibiotalar joint was performed by using T2-weighted and dual-echo 2-dimensional sequences with spectral fat saturation and a 3-dimensional, T2-weighted inversion recovery sequence. Besides evaluation of nerve T2-weighted signal, detailed quantification of nerve injury by morphometric (nerve caliber) and microstructural MRN markers (proton spin density, T2 relaxation time) was conducted.

Results

Nerve T2-weighted signal increase correlated with disease severity: moderate (420.2 ± 60.1) vs mild AL-PNP (307.2 ± 17.9; p = 0.0003) vs controls (207.0 ± 6.4; p < 0.0001). Proton spin density was also higher in moderate (tibial: 525.5 ± 53.0; peroneal: 553.6 ± 64.5; sural: 492.0 ± 56.6) and mild AL-PNP (tibial: 431.6 ± 22.0; peroneal: 457.6 ± 21.7; sural: 404.8 ± 25.2) vs controls (tibial: 310.5 ± 14.1; peroneal: 313.6 ± 11.6; sural: 261.7 ± 11.0; p < 0.0001 for all nerves). T2 relaxation time was elevated in moderate AL-PNP only (tibial: p = 0.0106; peroneal: p = 0.0070; sural: p = 0.0190). Tibial nerve caliber was higher in moderate (58.0 ± 8.8 mm3) vs mild AL-PNP (46.5 ± 2.5 mm3; p = 0.008) vs controls (39.1 ± 1.2 mm3; p < 0.0001).

Conclusions

MRN detects and quantifies peripheral nerve injury in AL-PNP in vivo with high sensitivity and in close correlation with the clinical stage. Quantitative parameters are feasible new imaging biomarkers for the detection of early AL-PNP and might help to monitor microstructural nerve tissue changes under treatment.

Advances in the understanding of IgM monoclonal gammopathy of undetermined significance

Among monoclonal gammopathies of undetermined significance (MGUSs), the immunoglobulin M (IgM) MGUS subtype stands as a unique entity and plays a pivotal role as a pre-malignant condition for multiple B-cell non-Hodgkin lymphomas, most notably Waldenström macroglobulinemia (WM). A relationship between IgM MGUS and WM has been proposed for decades. However, insight regarding the pathobiology of these two conditions improved significantly in recent years, strengthening the hypothesis that WM and IgM MGUS are different stages of the same disease. Therefore, the understanding of IgM MGUS and that of WM are interconnected and advances in one will likely impact the other. Furthermore, IgM MGUS has been more commonly recognized as the underlying etiology of IgM-related disorders. In this review, we explore recent advances in the understanding of the pathobiology of IgM MGUS and WM and the treatment of common IgM-related disorders.

Content validation of the SF-36v2® health survey with AL amyloidosis patients

Background

This study examined the content validity of the SF-36v2® Health Survey (SF-36v2) in patients with AL amyloidosis using qualitative interviews with physicians and patients. The study included three distinct phases of qualitative research: concept elicitation interviews among physicians, concept elicitation interviews among patients, and cognitive debriefing interviews among patients. The concept elicitation interviews focused on areas of health-related quality of life that are affected by AL amyloidosis and may be affected by treatment, while patient cognitive debriefings aimed to confirm whether the SF-36v2 instructions, recall period, items, and response choices were comprehensive and understandable to AL amyloidosis patients.

Results

Physicians discussed the importance of measuring physical functioning, general health, mental/emotional health, sleep, fatigue, and work impact; though they also reported that they do not routinely use a standard Patient-Reported Outcome (PRO) measure of health-related quality of life. Patients described social, physical, role, and emotional impacts of AL amyloidosis and various treatments. Cognitive debriefing interviews confirmed the relevance of the concepts measured by the SF-36v2 and indicated that patients found the SF-36v2 both easy to understand and complete, that the SF-36v2 instructions and items were comprehensive and understandable without change, and the response choices and recall period were appropriate for use with patients with AL amyloidosis.

Conclusions

The findings support the content validity of the SF-36v2 as an appropriate measure of health-related quality of life in patients with AL amyloidosis.

Prognostic impact of immunoparesis at diagnosis and after treatment onset in patients with light-chain amyloidosis

OBJECTIVES

Immunoparesis (IP) is a risk factor associated with an unfavourable outcome in several plasma cell disorders. It has been suggested that its presence in light-chain (AL) amyloidosis could be associated with worse prognosis. However, the relevance of IP after treatment has not been evaluated to date. The aim of this study was to determine the prognostic impact of IP at diagnosis and one year after treatment onset in patients with AL amyloidosis.

METHODS

The clinical records of 69 patients with AL amyloidosis treated at a single institution from January 2006 to January 2016 were included in the study.

RESULTS

IP was observed in 27.5% of patients at diagnosis. The presence of IP was associated with a lower probability to achieve very good partial response or better after first-line treatment (37.8% versus 62.2%; p = .04). However, only in the group of patients treated with autologous stem cell transplantation (ASCT), the presence of IP resulted in a shorter progression-free survival (PFS) (30.2 months versus not reached [NR]; p = .02) but not in overall survival (OS). Persistence of IP at one year after treatment onset was identified in only four (9.8%) of the 41 evaluable patients. In the ASCT group, the absence of IP at one year after treatment onset resulted in a longer median PFS and OS (NR versus 22.6 months; p = .006; and NR versus 35.2 months; p < .001; respectively). In the multivariate analysis, the absence of IP at one year after treatment onset was independently associated with longer survival.

CONCLUSION

IP at diagnosis has a negative impact on survival while its absence at one year after treatment is an independent marker for long-term survival.

Overuse of organ biopsies in immunoglobulin light chain amyloidosis (AL): the consequence of failure of early recognition

INTRODUCTION

The diagnosis of amyloidosis requires histological confirmation of Congo-red (CR) deposits. The tissue source is preferably fat aspiration and/or bone marrow (BM) biopsy, but at times organ biopsy is required.

METHODS

We studied 612 patients with systemic immunoglobulin light chain amyloidosis to characterise the tissues used to establish the diagnosis.

RESULTS

The median number of tissue samples was 3. About 95% of BM biopsies were stained for CR, while 79% of patients had fat aspiration CR-stained. CR stain sensitivity was 69% in BM, 75% in fat aspiration and 89% for both sources combined. In comparison, CR sensitivity was 97-100% for heart, renal and liver biopsies. About 42% of patients with renal involvement, 21% of patients with liver involvement and 13% of patients with heart involvement underwent organ biopsy, when a less invasive biopsy would have established the diagnosis. Predictors for the requirement for organ biopsy were male sex, limited organ involvement and lack of fat aspiration.

DISCUSSION

Fat aspiration is underutilised for histologic confirmation of amyloidosis. A high rate of organ biopsies represents a failure to recognise the disease. Early awareness of amyloidosis in patients with organ dysfunction may lead to more judicious use of organ biopsies in this disease. Key messages Fat pad aspiration is underutilised to establish the diagnosis of amyloidosis. Bone marrow and fat pad aspiration obviates the need for invasive biopsies. The excessive use of organ biopsy in AL amyloidosis reflects failure to recognise the disease early in its course.

Characterization of isolated amyloid myopathy

BACKGROUND AND PURPOSE

Amyloid myopathy frequently occurs in the setting of systemic amyloidosis and less commonly in isolation (isolated amyloid myopathy). Anoctaminopathy-5 and dysferlinopathy were recently recognized as causes of isolated amyloid myopathy. The present study aimed to characterize the isolated amyloid myopathy and to compare it with amyloid myopathy associated with systemic amyloidosis.

METHODS

We searched the Muscle Laboratory database to identify patients with pathologically confirmed amyloid myopathy seen in neurology clinics between January 1998 and September 2016. Patients with monoclonal gammopathy, peripheral neuropathy, organomegaly or symptoms or pathologic evidence of amyloid deposition outside skeletal muscle were classified as having systemic amyloidosis-associated myopathy.

RESULTS

Fifty-two patients were identified, including 14 with isolated amyloid myopathy (eight anoctaminopathy-5, two dysferlinopathy and four genetically unknown) and 38 with systemic amyloidosis (32 immunoglobulin light-chain amyloidosis, four familial amyloid polyneuropathy and two senile systemic amyloidosis). Compared with patients with systemic amyloidosis, patients with isolated amyloid myopathy had a younger age of onset (median, 41.5 vs. 65 years), no dysphagia (0% vs. 26%) or weight loss (0% vs. 26%), but more frequent calf atrophy (57% vs. 0%), small collections of inflammatory cells on muscle biopsy (43% vs. 0%) and asymptomatic hyperCKemia at onset (21% vs. 0%). All patients with isolated amyloid myopathy had creatine kinase (CK) values >2.5 times the upper limit of normal.

CONCLUSIONS

Isolated amyloid myopathy accounts for 27% of patients with amyloid myopathy, mostly due to anoctaminopathy-5. There are various clinical and laboratory parameters that can help to differentiate isolated amyloid myopathy from systemic amyloidosis.

Transthyretin Cardiac Amyloidosis

PURPOSE OF REVIEW

Transthyretin (TTR)-related cardiac amyloidosis is a progressive infiltrative cardiomyopathy that mimics hypertensive, hypertrophic heart disease and may go undiagnosed. Transthyretin-derived amyloidosis accounts for 18% of all cases of cardiac amyloidosis. Thus, the study's purpose is to provide a comprehensive review of transthyretin cardiac amyloidosis.

RECENT FINDINGS

Wild-type transthyretin (ATTRwt) protein causes cardiac amyloidosis sporadically, with 25 to 36% of the population older than 80 years of age are at risk to develop a slowly progressive, infiltrative amyloid cardiomyopathy secondary to ATTRwt. In contrast, hereditary amyloidosis (ATTRm) is an autosomal dominant inherited disease associated with more than 100 point mutations in the transthyretin gene and has a tendency to affect the heart and nervous system. Up to 4% of African-Americans carry the Val122Ile mutation in the transthyretin gene, the most prevalent cause of hereditary cardiac amyloidosis in the USA. Identifying transthyretin cardiac amyloidosis requires increased awareness of the prevalence, signs and symptoms, and diagnostic tools available for discrimination of this progressive form of cardiomyopathy associated with left ventricular hypertrophy. While there are no FDA-approved medical treatments, investigation is underway on agents to reduce circulating mutated transthyretin.

Elevation of serum lactate dehydrogenase in AL amyloidosis reflects tissue damage and is an adverse prognostic marker in patients not eligible for stem cell transplantation

The significance of serum lactate dehydrogenase (LDH) in light chain (AL) amyloidosis has not been previously explored. We studied 1019 newly diagnosed patients and correlated the elevation of LDH above the upper limit of normal (ULN) with disease characteristics and outcome. Four hundred and nine patients had an LDH above ULN, representing 40% of the study population. Patients with an elevated LDH were older, were less likely to be male and had more extensive organ involvement compared to patients with a normal LDH. Patients with high LDH had greater cardiac and renal dysfunction. Elevated LDH was an independent prognostic marker for overall survival and for death within 6 months of diagnosis, but this was restricted to patients not eligible for stem cell transplant. Serum LDH may act as a marker for organ damage and should be explored as a potential marker for tissue healing and organ recovery.

Cardiac Amyloidosis and its New Clinical Phenotype: Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is now an emerging cardiovascular epidemic, being identified as the main phenotype observed in clinical practice. It is more associated with female gender, advanced age and comorbidities such as hypertension, diabetes, obesity and chronic kidney disease. Amyloidosis is a clinical disorder characterized by the deposition of aggregates of insoluble fibrils originating from proteins that exhibit anomalous folding. Recently, pictures of senile amyloidosis have been described in patients with HFpEF, demonstrating the need for clinical cardiologists to investigate this etiology in suspect cases. The clinical suspicion of amyloidosis should be increased in cases of HFPS where the cardio imaging methods are compatible with infiltrative cardiomyopathy. Advances in cardio imaging methods combined with the possibility of performing genetic tests and identification of the type of amyloid material allow the diagnosis to be made. The management of the diagnosed patients can be done in partnership with centers specialized in the study of amyloidosis, which, together with the new technologies, investigate the possibility of organ or bone marrow transplantation and also the involvement of patients in clinical studies that evaluate the action of the new emerging drugs.

Prognostic significance of interventricular septal thickness in patients with AL amyloidosis

The major prognostic determinant of immunoglobulin light chain (AL) amyloidosis is cardiac involvement. However, the role of interventricular septal thickness (IVST), which reflects the extent of cardiac involvement, remains unclear. Therefore, we analyzed 77 patients with newly diagnosed AL amyloidosis and evaluated the prognostic role of IVST. Fifty patients (64.9%) had cardiac involvement and 17 patients (22.1%) showed IVST >15mm. Among all patients, the revised Mayo Clinic Stage III-IV and IVST >15mm were independently associated with inferior overall survival (OS) in a multivariable analysis. IVST >15mm was also adversely prognostic for OS in a subgroup of advanced-stage (revised Mayo Clinic stage III-IV) patients in a multivariable analysis (P<0.001). Furthermore, advanced-stage patients with IVST >15mm did not show survival benefit from treatment with bortezomib-based regimens and/or autologous stem-cell transplantation (ASCT). Our study demonstrated that IVST >15mm is adversely prognostic independent of the revised Mayo Clinic staging system in patients with AL amyloidosis. In addition, the degree of IVST might be used as a useful prognostic indicator that can guide the management of patients with AL amyloidosis especially at an advanced stage.

Clinical trials evaluating potential therapies for light chain (AL) amyloidosis

INTRODUCTION

The field of systemic amyloidosis is experiencing major advances in diagnostic and prognostic methods coupled with a growing availability in treatment options.

AREAS COVERED

Treatment of AL amyloidosis traditionally targeted the clonal plasma cells, in order to block further production of amyloidogenic light chains. Currently, a research focus is placed on targeting the already formed amyloid deposits using monoclonal antibodies against epitopes on such deposits. Encouraging results were obtained from the three investigated antibodies: NEOD001, 11-1F4 and anti-SAP, but further validation is required before these antibodies can be commercialized. In this paper, we review the current active clinical research in AL amyloidosis, which includes the monoclonal antibodies targeting amyloid deposits, daratumumab, Venetoclax, doxycycline, green tea, pomalidomide, carfilzomib and ixazomib.

EXPERT OPINION

Monoclonal antibodies, targeting either the amyloid deposits or the plasma cell compartment will likely be integrated into routine treatment practice given their encouraging results and minimal toxicity in the fragile population of AL amyloidosis. Other therapeutic options hold promise to the field as well, but toxicity will likely challenge their routine use. Early recognition remains the best option for outcome enhancement.

Addressing Common Questions Encountered in the Diagnosis and Management of Cardiac Amyloidosis

Advances in cardiac imaging have resulted in greater recognition of cardiac amyloidosis in everyday clinical practice, but the diagnosis continues to be made in patients with late-stage disease, suggesting that more needs to be done to improve awareness of its clinical manifestations and the potential of therapeutic intervention to improve prognosis. Light chain cardiac amyloidosis, in particular, if recognized early and treated with targeted plasma cell therapy, can be managed very effectively. For patients with transthyretin amyloidosis, there are numerous therapies that are currently in late-phase clinical trials. In this review, we address common questions encountered in clinical practice regarding etiology, clinical presentation, diagnosis, and management of cardiac amyloidosis, focusing on recent important developments in cardiac imaging and biochemical diagnosis. The aim is to show how a systematic approach to the evaluation of suspected cardiac amyloidosis can impact the prognosis of patients in the modern era.

The burden of amyloid light chain amyloidosis on health-related quality of life

Background

Light chain (AL) amyloidosis is a rare disease characterized by misfolded amyloid protein deposits in tissues and vital organs, and little is known about the burden of AL amyloidosis on health-related quality of life. This study aimed to quantify the burden of AL amyloidosis in terms of health-related quality of life in a diverse, community-based sample of AL amyloidosis patients.

Results

The SF-36v2® Health Survey (SF-36v2), a widely used generic measure of health-related quality of life (using physical and mental summary scales and subscales assessing eight aspects of functioning and well-being), was administered as an online survey of AL amyloidosis patients with AL amyloidosis (ClinicalTrials.gov, NCT02574676; n = 341). Compared with adjusted general population sample norms, health-related quality of life of AL amyloidosis patients was significantly worse across all SF-36v2 scales and summary measures based on analysis of variance (p < 0.05 for all). The largest decrement in AL amyloidosis patients was related to General Health (Δ = 9.7; p < 0.001). With the exception of Bodily Pain and Mental Health, differences were also clinically meaningful based on established clinically minimal important differences. The burden of AL amyloidosis overall and in key subgroups tended to be greater on physical health than on mental health. Stratified analyses indicated additional burden among patients with recently diagnosed disease and those with cardiac involvement than among their respective counterparts.

Conclusion

Understanding the burden of AL amyloidosis highlights the unmet need for treatment, helps physicians identify ancillary treatments and services geared towards improving patients’ functioning, well-being, and overall health-related quality of life. These findings also help to support the use of health-related quality of life end points as important outcome measures in current and future treatment studies.

Trial registration

ClinicalTrials.gov, NCT02574676. Registered October 5, 2015.

Regression of cardiac amyloidosis following stem cell transplantation: a comparison between echocardiography and cardiac magnetic resonance imaging in long-term survivors

BACKGROUND

AL amyloidosis and multiple myeloma result in extracellular deposition of insoluble fibrillary protein in tissue and organs. Untreated median survival is very poor, and even worse with cardiac involvement. Chemotherapy and peripheral blood stem cell transplantation (PBSCT) have been shown to dramatically improve survival, with hematologic remission documented. Regression of cardiac changes has previously been shown, as assessed by echocardiography (TTE) and cardiac magnetic resonance imaging (CMR). This study is a comparison of TTE and CMR in long-term survivors of cardiac amyloidosis with regression.

RESULTS

Four long-term survivors with cardiac amyloidosis and regression of cardiac features on TTE were identified. Mean age was 60 years and average survival was 139 months from the time of diagnosis of cardiac involvement. Statistically significant regression of the cardiac features of cardiac amyloidosis were demonstrated on TTE. In these survivors, post-PBSCT structural assessments were similar between TTE and CMR. Classical strain imaging features of cardiac amyloidosis were only present in 50%. All patients had diffuse, patchy gadolinium enhancement on CMR after PBSCT.

CONCLUSIONS

Treatment of cardiac amyloidosis with chemotherapy and PBSCT may result in regression of abnormalities on TTE with marked improvement in survival. Post treatment, TTE and CMR structural assessments appear similar. Gadolinium imaging suggests that microscopic residual infiltration persists despite macroscopic regression. Significant cardiac improvements with prolonged survival are seen nonetheless. Multimodality imaging has a vital role in the management of cardiac amyloidosis.

Macroglossia as a presenting feature of multiple myeloma

Macroglossia has been very rarely reported as a first clinical sign of multiple myeloma.