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Aims: transthyretin amyloid cardiomyopathy (ATTR-CM) is predominantly diagnosed in men. The few available studies suggest affected women have a more favourable cardiac phenotype. We aimed to characterize sex differences among consecutive patients with non-hereditary and two prevalent forms of hereditary (h)ATTR-CM diagnosed over a 20-year period. Methods and results: analysis of deep phenotyping at presentation, changes on serial echocardiography and overall prognosis were evaluated. In total, 1732 consecutive patients were studied, comprising: 1095 with wild-type (wt)ATTR-CM; 206 with T60A-hATTR-CM; and 431 with V122I-hATTR-CM. Female prevalence was greater in T60A-hATTR-CM (29.6%) and V122I-hATTR-CM (27.8%) compared to wtATTR-CM (6%). At presentation, females were 3.3 years older than males (wtATTR-CM: 81.9 vs. 77.8 years; T60A-hATTR-CM: 68.7 vs. 65.1 years; V122I-hATTR-CM: 77.1 vs. 74.9 years). Body size significantly influenced measures of disease severity; when indexed, overall structural and functional phenotype was similar between sexes, the few significant differences suggested a mildly worse phenotype in females. No significant differences were observed in both disease progression on serial echocardiography and mortality across the overall population (p = 0.459) and when divided by genotype (wtATTR-CM: p = 0.730; T60A-hATTR-CM: p = 0.161; V122I-hATTR-CM: p = 0.056). Conclusion: this study of a well-characterized large cohort of ATTR-CM patients did not demonstrate overall differences between sexes in either clinical phenotype, when indexed, or with respect to disease progression and prognosis. Non-indexed wall thickness measurements may have contributed to both under-representation and delays in diagnosis for affected females and highlights the potential role of utilizing indexed echocardiographic parameters for a more accurate assessment of patients at diagnosis and for disease prognostication.

The effect of liposomes bi-functionalized with phosphatidic acid and with a synthetic peptide derived from human apolipoprotein E has been evaluated on the aggregation features of different amyloidogenic proteins: human Amyloid β1–40 (Aβ1–40), transthyretin (TTR) variant S52P, human β2microglobulin (β2m) variants ΔN6 and D76N, Serum Amyloid A (SAA). The formation of fibrillar aggregates of the proteins was investigated by ThioflavinT fluorescence assay and validated by Atomic Force Microscopy. The results show that liposomes are preventing the transition of non-aggregated forms to the fibrillar state, with stronger effects on Aβ1–40, β2m ΔN6 and SAA. Liposomes also induce disaggregation of the amyloid aggregates of all the proteins investigated, with stronger effects on Aβ1–40, β2 D76N and TTR. SPR assays show that liposomes bind Aβ1–40 and SAA aggregates with high affinity (KD in the nanomolar range) whereas binding to TTR aggregates showed a lower affinity (KD in the micromolar range). Aggregates of β2m variants showed both high and low affinity binding sites. Computed Structural analysis of protein fibrillar aggregates and considerations on the multidentate features of liposomes allow to speculate a common mechanism of action, based on binding the β-stranded peptide regions responsible for the amyloid formation. Thus, multifunctional liposomes perform as pharmacological chaperones with anti-amyloidogenic activity, with a promising potential for the treatment of a number of protein-misfolding diseases.Key messageAmyloidosis is a group of diseases, each due to a specific protein misfolding.Anti-amyloidogenic nanoparticles have been gaining the utmost importance as a potential treatment for protein misfolding disorders.Liposomes bi-functionalized with phosphatidic acid and with a synthetic peptide derived from human apolipoprotein E showed anti-amyloidogenic activity. Amyloidosis is a group of diseases, each due to a specific protein misfolding. Anti-amyloidogenic nanoparticles have been gaining the utmost importance as a potential treatment for protein misfolding disorders. Liposomes bi-functionalized with phosphatidic acid and with a synthetic peptide derived from human apolipoprotein E showed anti-amyloidogenic activity.

ObjectivesAmyloid light chain (AL)-κ and AL-λ share common histopathologic changes; however, the potential difference in clinical manifestations, histologic findings, and clinical significance between the 2 subtypes remain unclear.MethodsIn a retrospective study, 94 kidney biopsies for AL amyloidosis were evaluated using the composite scarring injury score (CSIS) and amyloid score (AS). Results were then compared between AL-κ and AL-λ.ResultsComparing AS and CSIS between AL-κ and AL-λ, the AS was significantly higher in AL-κ than in AL-λ, with 2 components of AS (capillary wall and vascular amyloid) scoring higher in AL-κ than in AL-λ, while mesangial and interstitial ASs were similar in the 2 cohorts. In addition, the proportion of periodic acid–Schiff strong-staining amyloid in AL-κ was markedly higher than in AL-λ. There was no significant difference in CSIS and its components between the 2 subtypes of AL amyloidosis.ConclusionsOverall, AL-κ presents with higher serum creatinine and a higher AS score than AL-λ at biopsy, which may indicate a worse prognosis and be an important reference for clinical management.

Aims: Cardiac amyloidosis (CA) is due to a deposition of amyloid fibrils in the heart causing an increase in wall thickness. A left ventricular (LV) wall thickness ≥12 mm plus at least one red flag should raise the suspicion of CA. As normal values of LV wall thickness are lower in women, the adoption or the same cut-off values for men and women could lead to underdiagnosis or delayed diagnosis in women. We investigated the relationship between LV wall thickness and the severity of cardiac involvement in women and men with transthyretin (ATTR) CA. Methods and results: We evaluated 330 consecutive patients diagnosed with ATTR-CA at three centres (Pisa, n = 232; Brescia, n = 69; Trieste, n = 29). Interventricular septum (IVS) and posterior wall (PW) thickness values were lower in women (n = 53, 16%) than men, but most differences were abolished when indexing by body surface area (BSA), height, or height, suggesting similar disease severity when accounting for the smaller body size of women. PW thickness indexed for height was even higher in women. We also searched for correlations between IVS and PW thickness and other indicators of the severity of cardiac disease. IVS values indexed by height displayed tighter associations with N-terminal pro-B-type natriuretic peptide values than non-indexed IVS values. Similarly, indexed values displayed closer relationships with relative wall thickness, E/e' ratio, and tricuspid annular plane systolic excursion. Conclusions: Indexed LV wall thickness values, particularly by height, reflect more accurately the severity of cardiac involvement than non-indexed values.

Backgrounds Hereditary transthyretin amyloidosis (ATTRv) presymptomatic subjects undergo multidisciplinary evaluation to detect, as early as possible, a subclinical involvement of multisystem disease. Quantitative sensory testing (QST) that investigates and discriminates the function of C, Aδ and Aβ fibers is included as an instrumental test to monitor nerve fiber function. The purpose of this study was to evaluate the role of QST in the context of the multidisciplinary evaluation in late onset carriers. Methods Four-teen presymptomatic (namely carriers) were enrolled. Subjects underwent thermal [cold and warm detection threshold (CDT, WDT), cold and heat pain (CP and HP)] and tactile QST in four body sites: foot dorsum, distal lateral leg, distal thigh, hand dorsum. Results Overall, presymptomatic subject showed a significant difference in all thermal QST findings compared to the control group. All subjects had at least one altered thermal QST finding; the sites more frequently altered were foot and leg, whilst the thermal modalities which were more frequently abnormal were CDT, WDT and CP. Conclusions Our study highlights the importance of performing thermal QST in subjects carrying TTR mutation, given the high frequency of abnormal findings. Notably, performing both innocuous and painful stimulation in foot and/or leg increases the chance of detecting nerve fiber dysfunction. Moreover, the investigation of the hand may provide useful information in monitoring disease progression before the Predicted Age of Disease Onset (PADO).

Background: Diagnostic and therapeutic advances have led to much greater awareness of transthyretin cardiac amyloidosis (ATTR-CA). We aimed to characterize changes in the clinical phenotype of patients diagnosed with ATTR-CA over the past 20 years. Methods: This is a retrospective observational cohort study of all patients referred to the National Amyloidosis Centre (2002–2021) in whom ATTR-CA was a differential diagnosis. Results: We identified 2995 patients referred with suspected ATTR-CA, of whom 1967 had a diagnosis of ATTR-CA confirmed. Analysis by 5-year periods revealed an incremental increase in referrals, with higher proportions of patients having been referred after bone scintigraphy and cardiac magnetic resonance imaging (2% versus 34% versus 51% versus 55%, chi-square P P P P P =0.01) and higher left ventricular ejection fraction (46.0%±8.9% versus 46.8%±11.0% versus 47.8%±11.0% versus 49.5%±11.1%, P P P P Conclusions: There has been a substantial increase in ATTR-CA diagnoses, with more patients being referred after local advanced cardiac imaging. Patients are now more often diagnosed at an earlier stage of the disease, with substantially lower mortality. These changes may have important implications for initiation and outcome of therapy and urgently need to be factored into clinical trial design.

Hereditary transthyretin (TTR) amyloidosis (ATTRv) is a dominantly inherited, adult-onset, progressive, and fatal disease caused by mutations in the transthyretin gene. Therapeutic agents approved for this disease include the TTR stabilizer tafamidis and the gene-silencing drugs patisiran and inotersen. Inotersen is an antisense oligonucleotide that suppresses the hepatic production of transthyretin. After European Medical Agency approval in 2018, an early-access program was opened in Italy, and in this article, we present the long-term outcome of a cohort of Italian ATTRv patients who received inotersen within this program.This is a multicenter, observational, retrospective study of patients affected by ATTRv that started inotersen during the early-access program. The primary end point was safety. Secondary end points included change from baseline in familial amyloid polyneuropathy (FAP) stage, Polyneuropathy Disability, Neuropathy Impairment Scale, Compound Autonomic Dysfunction Test, Norfolk Quality of Life-Diabetic Neuropathy, troponin, N-terminal pro-brain natriuretic peptide, interventricular septum thickness, and body mass index.In total, 23 patients were enrolled. No patient permanently discontinued the treatment because of thrombocytopenia, and no cases of severe thrombocytopenia were observed. Five patients discontinued the treatment permanently because of voluntary withdrawal (two patients), renal failure after infective pyelonephritis, not related to inotersen, drug-related hypotension, and amyloid-negative crescentic glomerulonephritis. In seven patients, dosing frequency was reduced to every 2 weeks due to recurrent thrombocytopenia. Considering the FAP stage, only two patients worsened, whereas the other 21 patients remained stable until the last follow-up available.The long-term safety profile of inotersen is favorable. Neurologic disease severity at baseline is the main factor associated with progression.

Amyloid cardiomyopathy is a condition characterized by intra-myocardial deposit of protein-like material, in fibrillar shape (amyloid), which presence determine a progressive thickening and stiffening of the cardiac walls leading to a cardiac dysfunction. The proteins most often involved with cardiac amyloid are the light chains of the immunoglobulin, typical of amyloidosis AL, and transthyretin, responsible for transthyretin amyloidosis, in both its forms, hereditary and wild type. An accurate estimate of the incidence of cardiac amyloidosis is still difficult due to the variety and complexity of the clinical presentation of the condition. Nonetheless, the condition has stimulated the interest of the scientific community, so that a specific diagnostic path has been developed, beginning from the clinical suspicion and first-line testing, such as electrocardiogram, echocardiogram, and blood work, to progress to the diagnostic confirmation using more sophisticated testing such as magnetic resonance, scintiscan, and eventually cardiac biopsy. To understand and recognize this condition is very important, stemming from the availability of ‘aetiology oriented therapies’ (designed to prevent, control and possibly regress amyloid deposition), which should be added to the ‘supportive therapies’, used for the treatment of the complication of the condition, namely heart failure.

Amyloid diseases are global epidemics with no cure currently available. In the past decade, the use of engineered nanomaterials as inhibitors or probes against the pathogenic aggregation of amyloid peptides and proteins has emerged as a new frontier in nanomedicine. In this Minireview, we summarize for the first time the pivotal role of chemical synthesis in enabling the development of this multidisciplinary field.

Amyloidoses are characterized by the accumulation and aggregation of misfolded proteins into fibrils in different organs, leading to cell death and consequent organ dysfunction. The specific substitution of Leu 75 for Pro in Apolipoprotein A-I protein sequence (ApoA-I; L75P-ApoA-I) results in late onset amyloidosis, where deposition of extracellular protein aggregates damages the normal functions of the liver. In this work, we describe that the autophagic process is inhibited in the presence of the L75P-ApoA-I amyloidogenic variant in stably transfected human hepatocyte carcinoma cells. The L75P-ApoA-I amyloidogenic variant alters the redox status of the cells, resulting into excessive mitochondrial stress and consequent cell death. Moreover, L75P-ApoA-I induces an impairment of the autophagic flux. Pharmacological induction of autophagy or transfection-enforced overexpression of the pro-autophagic transcription factor EB (TFEB) restores proficient proteostasis and reduces oxidative stress in these experimental settings, suggesting that pharmacological stimulation of autophagy could be a promising target to alleviate ApoA-I amyloidosis.

Restrictive cardiomyopathy (RCM) is a heterogeneous group of diseases characterized by restrictive left ventricular pathophysiology, i.e. a rapid rise in ventricular pressure with only small increases in filling volume due to increased myocardial stiffness. More precisely, the defining feature of RCM is the coexistence of persistent restrictive pathophysiology, diastolic dysfunction, non-dilated ventricles, and atrial dilatation, regardless of ventricular wall thickness and systolic function. Beyond this shared haemodynamic hallmark, the phenotypic spectrum of RCM is wide. The disorders manifesting as RCM may be classified according to four main disease mechanisms: (i) interstitial fibrosis and intrinsic myocardial dysfunction, (ii) infiltration of extracellular spaces, (iii) accumulation of storage material within cardiomyocytes, or (iv) endomyocardial fibrosis. Many disorders do not show restrictive pathophysiology throughout their natural history, but only at an initial stage (with an evolution towards a hypokinetic and dilated phenotype) or at a terminal stage (often progressing from a hypertrophic phenotype). Furthermore, elements of both hypertrophic and restrictive phenotypes may coexist in some patients, making the classification challenge. Restrictive pathophysiology can be demonstrated by cardiac catheterization or Doppler echocardiography. The specific conditions may usually be diagnosed based on clinical data, 12-lead electrocardiogram, echocardiography, nuclear medicine, or cardiovascular magnetic resonance, but further investigations may be needed, up to endomyocardial biopsy and genetic evaluation. The spectrum of therapies is also wide and heterogeneous, but disease-modifying treatments are available only for cardiac amyloidosis and, partially, for iron overload cardiomyopathy.

Over the last year, 5 national or international scientific societies have issued documents regarding cardiac amyloidosis (CA) to highlight the emerging clinical science, raise awareness, and facilitate diagnosis and management of CA. These documents provide useful guidance for clinicians managing patients with CA, and all include: 1) an algorithm to establish a diagnosis; 2) an emphasis on noninvasive diagnosis with the combined use of bone scintigraphy and the exclusion of a monoclonal protein; and 3) indications for novel disease-modifying therapies for symptomatic CA, either with or without peripheral neuropathy. Nonetheless, the documents diverge on specific details of diagnosis, risk stratification, and treatment. Highlighting the similarities and differences of the documents by the 5 scientific societies with respect to diagnosis, risk stratification, and treatment offers useful insight into the knowledge gaps and unmet needs in the management of CA. An analysis of these documents, therefore, highlights "gray zones" requiring further investigation.

Apolipoprotein A-I (ApoA-I) amyloidosis is a rare protein misfolding disease where fibrils of the N-terminal domain of the protein accumulate in several organs, leading to their failure. Although ApoA-I amyloidosis is systemic, the different amyloidogenic variants show a preferential tissue accumulation that appears to correlate with the location of the mutation in the protein sequence and with the local extracellular microenvironment. However, the factors leading to cell/tissues damage, as well as the mechanisms behind the observed organ specificity are mostly unknown. Therefore, we investigated the impact of ApoA-I variants on cell physiology and the mechanisms driving the observed tissue specificity. We focused on four ApoA-I amyloidogenic variants and analyzed their cytotoxicity as well as their ability to alter redox homeostasis in cell lines from different tissues (liver, kidney, heart, skin). Moreover, variant-specific interactions with extracellular matrix (ECM) components were measured by synchrotron radiation circular dichroism and enzyme-linked immunosorbent assay. Data indicated that ApoA-I variants exerted a cytotoxic effect in a time and cell-type-specific manner that seems to be due to protein accumulation in lysosomes. Interestingly, the ApoA-I variants exhibited specific preferential binding to the ECM components, reflecting their tissue accumulation pattern in vivo. While the binding did not to appear to affect protein conformations in solution, extended incubation of the amyloidogenic variants in the presence of different ECM components resulted in different aggregation propensity and aggregation patterns.

Cardiac amyloidosis is an infiltrative disorder caused by transthyretin or immunoglobulin free light-chain deposition, which determines clinical disease with similar phenotype but different time course, prognosis and therapy. Multimodality imaging is the cornerstone for disease diagnosis and management. Multimodality imaging has revolutionized the approach to the disease favoring its awareness and simplifying its diagnosis, especially in ATTR cardiac amyloidosis. This describes the different imaging tools, from the traditional to the more novel ones, and highlights the different approach in each different setting (prognosis, subtyping, prognosis, monitoring disease progression, and response to therapy).

The authors present a case of fatal amyloid cardiomyopathy, which was diagnosed only upon autopsy. A 57-year-old man was admitted to the hospital for scheduled percutaneous cardiac procedure of transcatheter radiofrequency ablation due to persistent atrial fibrillation and atrial flutter. Ventricular fibrillation was recorded in the monitor 2 h after the surgical procedure. Therefore, he was defibrillated and intubated, but he died for nosocomial pneumonia 26 days after being admitted. A judicial autopsy was ordered by the prosecutor due to an alleged medical malpractice. The autopsy confirmed the cause of death being pneumonia, but also revealed an occult restrictive cardiomyopathy with a thick and firm myocardium. Viscera samples were then collected for microscopic examination. Histopathologic analysis showed diffuse amyloid deposits in the myocardium, especially in the perivascular and subendocardial spaces. Amyloid deposits were also detected in all the other organs, except for the brain. Furthermore, immunohistochemistry for light chains was performed on the heart tissue sample, resulting to be positive. In the case presented herein, autopsy and histopathologic examination were crucial to diagnose an occult systemic amyloidosis (AL-type). In fact, it has been observed that the rarity of systematic amyloidosis and its unusual clinical onset were at first mistakenly perceived as a medical malpractice due to a technical error within the catheter ablation for atrial fibrillation. As a consequence, upon discussing the clinical and medicolegal implications concerning the case, the focus was placed on the undiagnosed systemic amyloidosis and on the causality between surgical procedure and the patient's death.

Cardiac amyloidosis (CA) is increasingly diagnosed due to the advancements made in diagnostics and therapeutics in the last decades, particularly in the field of transthyretin-related CA. Studies that have used bone scintigraphy for screening at-risk conditions have shown that about one out of ten patients with heart failure with preserved ejection fraction (HFpEF), aortic stenosis undergoing valve replacement, or hypertrophic cardiomyopathy (HCM) diagnosed later in life might have an underlying or concomitant CA. At the same time, the epidemiology of these conditions is also rapidly evolving. HFpEF has become the leading form of heart failure, and HFpEF patients are increasingly cared for in non-cardiology settings due to their older age and substantial burden of comorbidities. Aortic stenosis is increasingly treated percutaneously at earlier stages of the disease, determining a significant gain in survival. Hypertrophic cardiomyopathy is nowadays mostly diagnosed in middle-aged adults with near-normal life expectancy, with a greater chance of misdiagnosing CA as HCM or of an overlap between the two conditions. In all these contexts, the therapeutic and prognostic implications of diagnosing CA will have to be further investigated. Meanwhile, the diagnostic workup of patients with suspected CA should always be completed with the systematic exclusion of a plasma cell dyscrasia, the acquisition of tomographic imaging at bone scintigraphy, and the completion of genetic testing for transthyretin-related forms.

Hereditary TTR amyloidosis (ATTRv) is a progressive e disabling disease, leading to a gradual loss of ambulation and death. In the last decade, new treatments have drastically revolutionized natural history of disease, and they are more efficacious if precociously administered. However, diagnostic delay still represents an important challenge to resolve. We reported a case of two asymptomatic brothers that received a very precocious diagnosis of ATTRv thanks to the diagnosis of carpal tunnel syndrome. We proposed screening of the well-defined carpal tunnel syndrome to detect patients with ATTRv in a pre-symptomatic stage.

Introduction This study aimed to validate the increased wall thickness (IWT) score, a multiparametric echocardiographic score to facilitate diagnosis of cardiac amyloidosis (CA), in an independent population of patients with increased LV wall thickness suspicious for CA. Methods Between January 2019 and December 2020, 152 consecutive patients with increased LV wall thickness suspicious for CA were included. For all patient, the multiparametric echocardiographic score (IWT score) was calculated. To validate the diagnostic accuracy of an IWT score ≥ 8 to predict the diagnosis of CA, sensibility (Se), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), and predictive accuracy (PA) were calculated. Results Among the 152 patients included in the study, 50 (33%) were diagnosed as CA, 25 (16%) had severe aortic stenosis, 25 (16%) had hypertensive remodeling, and 52 (34%) had hypertrophic cardiomyopathy. Among the 50 and 102 patients with and without CA, 19 (38%) and 1 (1%) showed an IWT score ≥ 8, respectively. Overall, the diagnostic accuracy of an IWT score ≥ 8 for the diagnosis of CA in our population was the following: Se 38% (95%CI 25–53%); Sp 99% (95%CI 95–100%); PPV 95% (95%CI 72–99%); NPV 77% (95%CI 73–80%); PA 79% (95%CI 72–85%). Conclusions This study reports the first external validation of the IWT score for the diagnosis of CA in patients with increased LV wall thickness. A score ≥ 8 showed a high Sp, PPV and PA, suggesting that the IWT score can be used to identify CA patients in those with increased LV wall thickness.

Protein function and flexibility is directly related to the native distribution of its structural elements and any alteration in protein architecture leads to several abnormalities and accumulation of misfolded proteins. This phenomenon is associated with a range of increasingly common human disorders, including Alzheimer and Parkinson diseases, type II diabetes, and a number of systemic amyloidosis characterized by the accumulation of amyloid aggregates both in the extracellular space of tissues and as intracellular deposits. Post-translational modifications are known to have an active role in the in vivo amyloid aggregation as able to affect protein structure and dynamics. Among them, a key role seems to be played by non-enzymatic glycation, the most unwanted irreversible modification of the protein structure, which strongly affects long-living proteins throughout the body. This study provided an overview of the molecular effects induced by glycation on the amyloid aggregation process of several protein models associated with misfolding diseases. In particular, we analyzed the role of glycation on protein folding, kinetics of amyloid formation, and amyloid cytotoxicity in order to shed light on the role of this post-translational modification in the in vivo amyloid aggregation process.

Background: The prevalence of cardiac amyloidosis (CA) is unknown.Aims and Methods: We sought to (a) determine the prevalence of CA in unselected patients ≥75 years undergoing autopsy, (b) characterize cardiological profiles of CA and non-CA patients by providing clinical-histological correlations, and (c) compare their cardiological profiles. After dedicated staining, the localization (interstitial or vascular) and the distribution (non-diffuse or diffuse) of amyloid deposition were analyzed. Cardiological data at last evaluation were retrospectively assessed for the presence of CA red-flags.Results: CA (50% light chains, 50% transthyretin) was found in 43% (n = 24/56) of the autopsied hearts. Atria were involved in 96% of cases. Amyloid localized both at the perivascular and interstitial levels (95.5 and 85%, respectively) with a slightly predominant non-diffuse distribution (58% of cases). Compared to the other patients, CA patients had a more frequent history of heart failure (HF) (79 vs. 47%, p = 0.014), advanced NYHA functional class (III-IV 25 vs. 6%, p = 0.047), atrial fibrillation (68 vs. 36%, p = 0.019), discrepancy between QRS voltage and left ventricular (LV) thickness (70 vs. 12%, p < 0.001), thicker LV walls (15 vs. 11 mm, p < 0.001), enlarged left atrium (49 vs. 42 mm, p = 0.019) and restrictive filling pattern (56 vs. 19%, p = 0.020). The presence of right ventricular amyloidosis seemed to identify hearts with a higher amyloid burden. Among the CA patients, >30% had ≥3 echocardiographic red-flags of disease.Conclusion: CA can be found in 43% of autopsied hearts from patients ≥75 years old, especially in patients with HF, LV hypertrophy and atrial fibrillation.

Laryngeal amyloidosis is a rare and idiopathic disease that represents about 1% of all benign laryngeal lesions. It is characterized by the extracellular deposition of an abnormal amount of non-soluble fibrillar proteins in larynx. This disease presents unspecific symptoms and laringoscopic findings that make difficult to diagnose it. Management of these lesions consists of endoscopic resection of the mass through microdirect laryngoscopy. Recurrence is possible and it can occur up to 10 years after treatment; therefore a close and long-term follow-up is requested. A 60-year-old man presented with hoarseness and dysphonia. Laryngoscopy revealed a smooth, translucent and yellowish formation involving the middle-third of the left true vocal cord. The patient was first managed conservatively with speech therapy and after 6 months the lesion was removed by endoscopic CO2 laser surgery without evidence of recurrence in 2 years of follow-up. Laryngeal amyloidosis is a rare disorder that can be mistaken for a benign vocal cord polyp, nodule, retention cyst or laringocele. CO2 laser technique represents the highly effective approach to treat these lesions. Clinicians should know this rare amyloidosis site in order to avoid a delayed diagnosis and to treat it.

Purpose Localized amyloidosis of the tongue is a benign condition in which surgical management may be considered. The aim of the study was to review the current literature and report a case. Materials and Methods We searched the PubMed database for all relevant articles reporting cases of localized tongue amyloidosis published between 1980 and February 2020. In addition, we updated 1 case diagnosed and treated in our department. Results A 49-year-old male patient presented with an asymptomatic tongue nodule of the dorsum mimicking median rhomboid glossitis. The results of an incisional biopsy showed an amyloid on Congo red staining and positive findings for the κ light chain by immunohistochemical analysis. The findings of the systemic workup were negative. Therefore, a diagnosis of localized κ light-chain amyloidosis was made. The patient underwent a resection of the lesion, and no recurrence or progression was observed during a period of 18 months. The literature review showed 12 reports describing 21 patients (11 men, 52.3%) with localized tongue amyloidosis. The most common clinical presentation was nodular with a single lesion of the tongue dorsum (15 patients, 71.4%). All cases showed positive findings on Congo red staining. Immunohistochemical analysis findings were available for only 9 patients (42.8%) and showed light-chain amyloidosis. No case showed any systemic involvement or the development of systemic disease. Surgical excision was performed in 9 cases, with recurrence at the site of operation in 2 cases. Conclusions Localized amyloidosis of the tongue is a rare disease in which surgical excision may be therapeutic when a multidisciplinary evaluation does not show any systemic disease. We recommend an excision when the lesion is persistent or shows an enlargement or when discomfort is reported. In the case of any further local recurrence, resection may be repeated.

Hereditary amyloidogenic transthyretin (ATTRv) amyloidosis is a rare autosomal dominantly inherited disorder caused by mutations in the transthyretin (TTR) gene. The pathogenetic model of ATTRv amyloidosis indicates that amyloidogenic, usually missense, mutations destabilize the native TTR favouring the dissociation of the tetramer into partially unfolded species that self-assemble into amyloid fibrils. Amyloid deposits and monomer-oligomer toxicity are the basis of multisystemic ATTRv clinical involvement. Peripheral nervous system (autonomic and somatic) and heart are the most affected sites. In the last decades, a better knowledge of pathomechanisms underlying the disease led to develop novel and promising drugs that are rapidly changing the natural history of ATTRv amyloidosis. Thus, clinicians face the challenge of timely diagnosis for addressing patients to appropriate treatment. As well, the progressive nature of ATTRv raises the issue of presymptomatic testing and risk management of carriers. The main aim of this review was to focus on what we know about ATTRv so far, from pathogenesis to clinical manifestations, diagnosis and hence patient’s monitoring and treatment, and from presymptomatic testing to management of carriers.

Left ventricular hypertrophy is a common complication of different diseases. Among these, cardiac involvement of amyloidosis or Anderson-Fabry disease are often unrecognized. Early diagnosis is therefore crucial because new therapies can impact the progression of these diseases. Different specific signs unmasked by clinical, laboratory, and non-invasive diagnostic tests such as echocardiography or cardiac magnetic resonance could guide clinicians towards an appropriate diagnosis. The aim of this review is to underline the major diagnostic clues of different forms of left ventricular hypertrophy in adult patients, guiding clinicians towards a more appropriate diagnosis.

Purpose: To assess the clinical utility of 18F-Fluorodeoxyglucose positron emission tomography (FDG-PET) for detection of early signs of neurodegeneration in conditions of increased risk for Alzheimer’s disease (AD) as defined by: subjective cognitive decline (SCD), evidence of cerebral amyloid-pathology, apolipoprotein E (APOE) ε4-positive genotype, or autosomal dominant forms of AD (ADAD) in asymptomatic stages. Methods: A comprehensive literature search was conducted using the PICO model to extract evidence from relevant studies. An expert panel then voted using the Delphi method on three different diagnostic scenarios. Results: The level of empirical study evidence for the use of FDG-PET to detect meaningful early signs of neurodegeneration was considered to be poor for ADAD and lacking for SCD and asymptomatic persons at risk, based on APOE ε4-positive genotype or cerebral amyloid pathology. Consequently, and consistent with current diagnostic criteria, panelists decided not to recommend routine clinical use of FDG-PET in these situations and to currently mainly reserve it for research purposes. Conclusion: Currently, there is limited evidence on which to base recommendations regarding the clinical routine use of FDG-PET to detect diagnostically meaningful early signs of neurodegeneration in asymptomatic subjects with ADAD, with APOE ε4-positive genotype, or with cerebral amyloid pathology, and in subjects with SCD. Future prospective studies are warranted and in part already ongoing, aiming to assess the added value of FDG-PET in this context beyond research applications.

Deposition of amyloidogenic proteins leading to the formation of amyloid fibrils in the myocardium cause cardiac amyloidosis. Although any form of systemic amyloidosis can affect the heart, light-chain (AL) or transthyretin amyloidosis (ATTR) account for the majority of diagnosed cardiac amyloid deposition. The extent of cardiac disease independently predicts mortality. The reversal or arrest of adverse cardiac remodeling is the target of current therapies, as cardiac-related mortality worsens prognosis in patients where the underlying systemic amyloidosis was successfully treated. Here, we provide a condensed overview on the pathophysiology of AL and ATTR cardiac amyloidoses and describe treatments that are currently used or investigated in clinical or preclinical trials. We also briefly touch on acquired amyloid deposition in cardiovascular disease other than AL or ATTR.

Prion diseases are progressive neurodegenerative disorders affecting humans and other mammalian species. The term prion, originally put forward to propose the concept that a protein could be infectious, refers to PrP(Sc), a misfolded isoform of the cellular prion protein (PrP(C)) that represents the pathogenetic hallmark of these disorders. The discovery that other proteins characterized by misfolding and seeded aggregation can spread from cell to cell, similarly to PrP(Sc), has increased interest in prion diseases. Among neurodegenerative disorders, however, prion diseases distinguish themselves for the broader phenotypic spectrum, the fastest disease progression and the existence of infectious forms that can be transmitted through the exposure to diseased tissues via ingestion, injection or transplantation. The main clinicopathological phenotypes of human prion disease include Creutzfeldt–Jakob disease, by far the most common, fatal insomnia, variably protease‐sensitive prionopathy, and Gerstmann–Sträussler–Scheinker disease. However, clinicopathological manifestations extend even beyond those predicted by this classification. Because of their transmissibility, the phenotypic diversity of prion diseases can also be propagated into syngenic hosts as prion strains with distinct characteristics, such as incubation period, pattern of PrP(Sc) distribution and regional severity of histopathological changes in the brain. Increasing evidence indicates that different PrP(Sc) conformers, forming distinct ordered aggregates, encipher the phenotypic variants related to prion strains. In this review, we summarize the most recent advances concerning the histo‐molecular pathology of human prion disease focusing on the phenotypic spectrum of the disease including co‐pathologies, the characterization of prion strains by experimental transmission and their correlation with the physicochemical properties of PrP(Sc) aggregates.

Cardiac amyloidosis (CA) is a rare and phenotypically heterogeneous disease, with pathophysiological clinical and morphological variability. From an imaging point of view, CA is one of the cardiomyopathies with a hypertrophic phenotype and is frequently misdiagnosed on echocardiography as sarcomeric or idiopathic hypertrophic cardiomyopathy. However, there are morphological and functional features that could unravel the underlying myocardial infiltration, and relative apical sparing of longitudinal strain (LS) impairment is among the most specific and almost invariably reported findings.

Conformational plasticity and flexibility are key structural features of ApoAI in lipid metabolism. Amyloidogenic single point mutations, associated with incurable familial amyloidosis with fibril deposition in peripheral organs, may have a dramatic impact on the structural and functional features of ApoAI. Here, the consistent body of data on ApoAI variants has been reviewed, with the aim of highlighting the hallmarks of the pathology. In accordance with our observations, as well as that of others, we propose a model that accounts for the alteration of the delicate balance between lipid-free/lipid-bound dynamic states which is based on monomer-to-dimer interconversion via domain swapping.

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Aims: Cardiac amyloidosis remains a great challenge for the cardiologist. One of the three main aetiological forms, transthyretin-related hereditary amyloidosis (ATTRm), can present with several phenotypes, depending mainly on the specific mutation. We aimed to characterize the phenotype of patients with ATTRm due to Ile68Leu mutation, comparing them to patients with wild-type transthyretin amyloidosis (ATTRwt). Methods and results: Data of 67 Ile68Leu ATTRm patients from two Italian referral centres (Bologna and Florence) were retrospectively analysed and compared to those of 82 ATTRwt patients. Fifty-five unaffected mutation carriers were also analysed. Cumulative disease onset was 50% at age 71. A total of 56/67 (84%) patients had a predominantly cardiac phenotype at presentation with concentric increase in left ventricular wall thickness [median 17 mm], and normal or near normal left ventricular ejection fraction (79% of patients). Low QRS voltages were present only in 29% of patients but voltage/mass ratio was low (0.5). Carpal tunnel syndrome was noted in 43%. The overall phenotypic profile was similar to ATTRwt but Ile68Leu ATTRm patients typically presented younger (median 71 vs. 78 years) and were more likely to have (mild) symptomatic neurological involvement (19% vs. 2%). Male prevalence was 44% in unaffected mutation carriers and 78% in affected patients. Age-adjusted survival was comparable between groups. Conclusions: Ile68Leu ATTRm is a cause of familial amyloidotic cardiomyopathy endemic in central-northern Italy and presents as hypertrophic/restrictive cardiomyopathy quite similar to ATTRwt. Male preponderance is present in affected patients but not in unaffected mutation carriers. Age-adjusted survival is similar to ATTRwt.

Hypertrophic cardiomyopathy (HCM) is the most common known inherited heart disorder, with a prevalence of 1: 500 of the adult population. Etiology of HCM can be heterogeneous, with sarcomeric gene disease as the leading cause in up to 60% of the patients, and with a number of possible different diseases (phenocopies) in about 10%-15% of the patients. Early diagnosis of storage and infiltrative disorders, particularly those with specific treatments (i.e., Fabry disease and/or amyloidosis), means early management and treatment, with a significant impact on patients prognosis. Here, we report on four different cases of HCM, highlighting difficulties to make differential diagnosis of different forms of cardiomyopathies, and their potential impact on the management.

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Background Amyloidosis is a life threatening disease caused by deposition of various types of blood serum proteins in organs and tissues. Knowing the type of protein involved is the basis of a correct diagnosis and personalized medical treatment. While the classical approach uses immunohistochemistry, in recent years, laser micro-dissection, followed by high resolution LC-MS/MS, has been shown to provide superior diagnostic sensitivity and specificity. This techniques, however, is only available at major reference proteomics centers. Objective To perform clinical amyloid protein typing using low-resolution mass spectrometry and no laser micro dissection (LMD), we developed a targeted proteomics approach for the determination of both frequently encountered amyloid proteins (i.e., κ and -λ immunoglobulin light chains and transthyretin (TTR)) and specific reference proteins (i.e., actin (A) for cardiac muscle tissue, or fatty acid binding protein 4 (FBP4) for subcutaneous adipose tissue) in histologic specimens. Method Small tissue fragments and/or histological sections were digested to yield a protein mixture that was subsequently reduced, alkylated and trypsinized to obtain a peptide mixture. After SPE purification and LC separation, proteotypic peptides were detected by their MRM transitions. Results The method showed high specificity and sensitivity for amyloid protein proteotypic peptides. LODs were 1.0, 0.1, 0.2 picomoles in cardiac muscle tissue (CMT) and 0.1, 0.2, 0.5 picomoles in subcutaneous adipose tissue (SAT) for TTR, κ-, and λ-LC proteins, respectively. Amyloid to tissue-specific protein signal ratios correlated with the presence of amyloid deposits in clinical samples. Conclusions This targeted proteomics approach enables sensitive and specific discrimination of amyloidosis affected tissues for the purpose of clinical research.

Amyloid heart disease is one of the most frequent types of cardiomyopathy with restrictive pathophysiology. The familial amyloidoses constitute an extremely heterogeneous group of diseases. The form linked to transthyretin (TTR) mutations is by far the most common variety of familial amyloidosis. The clinical picture is non-specific with progressive chronic heart failure. A definitive diagnosis can readily be made from cardiac histopathology with evidence of amyloid deposits in other tissues. However, amyloid heart disease remains underdiagnosed. 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. The electrocardiographic and echocardiographic findings are often misleading and indistinguishable from other cardiac conditions including hypertrophic cardiomyopathy and coronary artery disease. In most cases, since the clinical manifestations of systemic amyloidosis are manifold, patients may be referred to any one of a variety of specialists (especially hematologists, nephrologists and neurologists) without necessarily referred to the cardiologist. For patients with transthyretin amyloidosis, there are numerous disease modifying therapies that are currently in late-phase clinical trials.

Background Cardiac magnetic resonance (CMR) has gained a central role in the diagnosis of cardiac amyloidosis (CA). While the diagnostic role of a typical late gadolinium enhancement (LGE) pattern (global subendocardial enhancement coupled with accelerated contrast washout) has been identified, evidence is still conflicting regarding the prognostic role of such examination. Methods and results We retrospectively analysed all patients referring for CMR at Niguarda Hospital (Milan, Italy) from January 2006 to January 2015 for suspected CA. Primary outcome was all-cause mortality. We identified 42 patients and divided them into 2 groups, according to the presence (Group A) or absence (Group B) of a typical amyloidosis LGE pattern. At the end of the followup (median 37 months, interquartile range 10–50 months), 31 patients (74%) had died. The hazard ratio for all-cause death was 3.2 (95% confidence interval [CI] 1.5–6.4, p < 0.01) for Group A versus Group B. Median survival time was 17 months (95% CI 7–42 months) for Group A and 70 months (95% CI 49–94 months) for Group B (p < 0.01). Multivariate analysis did not find any adjunctive predictive role for biventricular volumes and ejection fraction, indexed left ventricular mass, transmitral E/e’ at echocardiography, age at diagnosis or serum creatinine. Conclusion In our population, a typical LGE pattern was significantly associated with higher mortality. Moreover, patients with a typical LGE pattern showed a globally worse prognosis. Our data suggest that the LGE pattern may play a central role in prognostic stratification of patients with suspected CA, thus prompting further diagnostic and therapeutic measures

Background Specific apolipoprotein A-I variants are associated to severe hereditary amyloidoses. The organ distribution of AApoAI amyloidosis seems to depend on the position of the mutation, since mutations in residues from 1 to 75 are mainly associated to hepatic and renal amyloidosis, while mutations in residues from 173 to 178 are mostly responsible for cardiac, laryngeal, and cutaneous amyloidosis. Molecular bases of this tissue specificity are still poorly understood, but it is increasingly emerging that protein destabilization induced by amyloidogenic mutations is neither necessary nor sufficient for amyloidosis development. Methods By using a multidisciplinary approach, including circular dichroism, dynamic light scattering, spectrofluorometric and atomic force microscopy analyses, the effect of target cells on the conformation and fibrillogenic pathway of the two AApoAI amyloidogenic variants AApoAIL75P and AApoAIL174S has been monitored. Results Our data show that specific cell milieus selectively affect conformation, aggregation propensity and fibrillogenesis of the two AApoAI amyloidogenic variants. Conclusions An intriguing picture emerged indicating that defined cell contexts selectively induce fibrillogenesis of specific AApoAI variants. General significance An innovative methodological approach, based on the use of whole intact cells to monitor the effects of cell context on AApoAI variants fibrillogenic pathway, has been set up.

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.

Left ventricular hypertrophy (LVH) develops in response to a variety of physical, genetic, and biochemical stimuli and represents the early stage of ventricular remodeling. In patients with LVH, subclinical left ventricular (LV) dysfunction despite normal ejection fraction (EF) may be present before the onset of symptoms, which portends a dismal prognosis. Strain measurement with two-dimensional speckle tracking echocardiography (STE) represents a highly reproducible and accurate alternative to LVEF determination. The present review focuses on current available evidence that supports the incremental value of STE in the diagnostic and prognostic workup of LVH. When assessing the components of LV contraction, STE has an incremental value in differentiating between primary and secondary LVH and in the differential diagnosis with storage diseases. In addition, STE provides unique information for the stratification of patients with LVH, enabling to detect intrinsic myocardial dysfunction before LVEF reduction.

Histological analysis of endomyocardial tissue is still the gold standard for the diagnosis of cardiac amyloidosis, but has its limitations. Accordingly, there is a need for non-invasive modalities to diagnose cardiac amyloidosis. Echocardiography and ultrasound and magnetic resonance imaging can show characteristics which may not be very specific for cardiac amyloid. Nuclear medicine has gained a precise role in this context: several imaging modalities have become available for the diagnosis and prognostic stratification of cardiac amyloidosis during the last two decades. The different classes of radiopharmaceuticals have the potential to bind different constituents of the amyloidotic infiltrates, with some relevant differences among the various aetiologic types of amyloidosis and the different organs and tissues involved. This review focuses on the background of the commonly used modalities, their present clinical applications, and future clinical perspectives in imaging patients with (suspected) cardiac amyloidosis. The main focus is on conventional nuclear medicine (bone scintigraphy, cardiac sympathetic innervation) and positron emission tomography.

Systemic light chain (AL) amyloidosis is caused by the clonal production of an unstable immunoglobulin light chain (LC), which affects organ function systemically. Although pathogenic LCs have been characterized biochemically, little is known about the biology of amyloidogenic plasma cells (PCs). Intrigued by the unique response rates of AL amyloidosis patients to the first-in-class proteasome inhibitor (PI) bortezomib, we purified and investigated patient-derived AL PCs, in comparison with primary multiple myeloma (MM) PCs, the prototypical PI-responsive cells. Functional, biochemical, and morphological characterization revealed an unprecedented intrinsic sensitivity of AL PCs to PIs, even higher than that of MM PCs, associated with distinctive organellar features and expression patterns indicative of cellular stress. These consisted of expanded endoplasmic reticulum (ER), perinuclear mitochondria, and a higher abundance of stress-related transcripts, and were consistent with reduced autophagic control of organelle homeostasis. To test whether PI sensitivity stems from AL LC production, we engineered PC lines that can be induced to express amyloidogenic and nonamyloidogenic LCs, and found that AL LC expression alters cell growth and proteostasis and confers PI sensitivity. Our study discloses amyloidogenic LC production as an intrinsic PC stressor, and identifies stress-responsive pathways as novel potential therapeutic targets. Moreover, we contribute a cellular disease model to dissect the biology of AL PCs.

Background Individually, heart failure (HF) and Alzheimer's disease (AD) are severe threats to population health, and their potential coexistence is an alarming prospect. In addition to sharing analogous epidemiological and genetic profiles, biochemical characteristics, and common triggers, the authors recently recognized common molecular and pathological features between the 2 conditions. Whereas cognitive impairment has been linked to HF through perfusion defects, angiopathy, and inflammation, whether patients with AD present with myocardial dysfunction, and if the 2conditions bear a common pathogenesis as neglected siblings are unknown. Objectives Here, the authors investigated whether amyloid beta (Aβ) protein aggregates are present in the hearts of patients with a primary diagnosis of AD, affecting myocardial function. Methods The authors examined myocardial function in a retrospective cross-sectional study from a cohort of AD patients and age-matched controls. Imaging and proteomics approaches were used to identify and quantify Aβ deposits in AD heart and brain specimens compared with controls. Cell shortening and calcium transients were measured on isolated adult cardiomyocytes. Results Echocardiographic measurements of myocardial function suggest that patients with AD present with an anticipated diastolic dysfunction. As in the brain, Aβ40 and Aβ42 are present in the heart, and their expression is increased in AD. Conclusions Here, the authors provide the first report of the presence of compromised myocardial function and intramyocardial deposits of Aβ in AD patients. The findings depict a novel biological framework in which AD may beviewed either as a systemic disease or as a metastatic disorder leading to heart, and possibly multiorgan failure. ADandHF are both debilitating and life-threatening conditions, affecting enormous patient populations. Our findingsunderline a previously dismissed problem of a magnitude that will require new diagnostic approaches andtreatmentsforbrain and heart disease, and their combination.

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Amyloidoses are devastating diseases characterized by accumulation of misfolded proteins which aggregate in fibrils. Specific gene mutations in Apolipoprotein A I (ApoAI) are associated with systemic amyloidoses. Little is known on the effect of mutations on ApoAI structure and amyloid properties. Here we performed a physico-chemical characterization of L75P- and L174S-amyloidogenic ApoAI (AApoAI) variants to shed light on the effects of two single point mutations on protein stability, proteolytic susceptibility and aggregation propensity. Both variants are destabilized in their N-terminal region and generate fibrils with different morphological features. L75P-AApoAI is significantly altered in its conformation and compactness, whereas a more flexible and pronounced aggregation-competent state is associated to L174S-AApoAI. These observations point out how single point mutations in ApoAI gene evocate differences in the physico-chemical and conformational behavior of the corresponding protein variants, with the common feature of diverting ApoAI from its natural role towards a pathogenic pathway.

Peripheral neuropathies are frequent in association with systemic diseases as well as isolated disorders. Recent advances in the therapy of specific neuropathies led to the approval of new drugs/treatments. This review selected those peripheral neuropathies where the most recent approvals were provided and revised the potential future developments in diabetic and toxic-induced neuropathies, although they do not have a currently available causal therapy in view of their epidemiological and social relevance. Data have been extracted from the most important published trials and from clinical experience. In addition, data from the Food and Drug Administration and European Medicine Agency indications on the treatment of the selected peripheral neuropathies and from recently updated international guidelines have also been included. The website of the U.S. National Institutes of Health www.clinicaltrials.gov registry has been used as the reference database for phase III clinical trials not yet published or ongoing. This review gives a general overview of the most recent advances in the treatment of amyloid, inflammatory, and paraproteinemic peripheral neuropathies. Moreover, it briefly describes the unmet medical need in disabling and frequent conditions, such as diabetic and chemotherapy-induced neuropathy, highlighting the most promising therapeutic approaches to their treatment.

Among the different families of intracellular molecules that can be modulated during cell damage and repair, mitogen-activated protein kinases (MAPKs) are particularly interesting because they are involved in several intracellular pathways activated by injury and regeneration signals. Despite most of the studies have been performed in non-neurological models, recently a causal role for MAPKs has been postulated in central nervous system disorders. However, also in some peripheral neuropathies, MAPK changes can occur and these modifications might be relevant in the pathogenesis of the damage as well as during regeneration and repair. In this review, the current knowledge on the role of MAPKs in peripheral neuropathies will be discussed.

Background About twenty variants of apolipoprotein A-I (ApoA-I) are associated to hereditary systemic amyloidoses. Although the molecular bases of this disease are still largely unknown, it has been hypothesized that ApoA-I proteolysis is a key event in pathogenesis, since it triggers the release of an N-terminal fragment (80–100 residue long) that misfolds to form amyloid deposits in peripheral organs and tissues. It is also known that cell membrane lipids play a key role in the fibrillogenic pathway. In the case of ApoA-I related amyloidosis caused by L174S mutation, the 93-residue N-terminal fragment of ApoA-I ([1-93]ApoA-I) was found to be the major constituent of ex vivo fibrils. Methods With the main goal to investigate the interaction of either [1-93]ApoA-I and ApoA-I with biomimetic membranes, we set-up an experimental system based on the Raman Tweezers methodology. We tested GUVs composed by two types of zwitterionic lipids with a different fluidity degree, i.e. dioleoylphosphatidylcholine (DOPC) and dipalmitoylphosphatidylcholine (DPPC). Results We found that [1-93]ApoA-I induces conformational disorder in an ordered lipid bilayer. When interacting with fluid phases, instead, the fragment was found to be able to penetrate the membrane bilayer inducing an alignment of lipid chains. Conclusions The interaction features of [1-93]ApoA-I with biomimetic membranes strongly depend on the lipid phase. Full-length ApoA-I was found to have similar effects, even if significantly less pronounced. General significance Our observations shed light on still largely unknown molecular bases of ApoA-I fibrillogenic domain interaction with membranes.

Background: Although atrial fibrillation (AF) is a known complication of amyloidotic cardiomyopathy (AC), a precise pathophysiological and prognostic characterization is not available. We therefore aimed to assess prevalence, incidence, risk factors and prognostic significance of AF in light-chain (AL), hereditary transthyretin-related (m-ATTR) and non-mutant transthyretin-related (wt-ATTR) AC. Methods: Retrospective study of 262 patients with AC (123 AL, 94 m-ATTR, 45 wt-ATTR) from a single center. Results: AF prevalence was 15% (AL 9%, m-ATTR 11%, wt-ATTR 40%). During a median follow-up of 1.2 years 11 patients developed AF (2.1% person-years). Age, heart failure (HF), left ventricular (LV) ejection fraction, renal involvement, left atrial size and right atrial pressure were independently associated with AF. AF was associated with incident HF but not with increased mortality. All AF patients were prescribed warfarin and none suffered thromboembolic events. Conclusions: In AC the prevalence of AF varies widely according to etiology with a mean value of 15% that reaches 40% in wt-ATTR amyloidosis. Age, HF, LV ejection fraction, left atrial size and right atrial pressure were the main independent risk factors, while wall thickness and etiology were not the main independent risk factors. AF does not seem to impact all-cause mortality but was strongly associated with prevalent and incident HF.

To the Editor: Recently, some authors defined the so-called monoclonal gammopathy of renal significance (MGRS), characterized by the presence of plasma cell dyscrasia, with the main renal damage and discriminated from classic monoclonal gammopathy of uncertain significance (MGUS) by a less benign course.1, 2 We appreciate the very exhaustive review of Bridoux et al.,3 in which they defined useful criteria to diagnose this entity, linking the development of MGRS with many hematological diseases. Contributing to this classification, we describe the interesting association between a controversial condition and renal impairment due to amyloid deposition, even without an evident plasma cell neoplastic clone. AL amyloidosis represents a frequent epiphenomenon of plasma cells dyscrasia (PCD), and their association has been extensively studied during past years.4, 5, 6, 7 Although systemic involvement is more likely linked with advanced diseases, like multiple myeloma (MM), conditions always considered as benign could give rise to such manifestations, with adequate latency periods, as described by Kourelis et al.4 For this reason, and for an adequate management, careful diagnostic assessment of these entities is crucial, and the recent development of more sensitive tools had a key role in this field. This improvement allowed the evolution of such condition defined by Mian et al.5 as idiopathic Bence-Jones proteinuria (iBJP), later revised by Dispenzieri et al.6 with the aid of serum free light chain (FLC) detection systems. In this context, we recently evaluated the case of a 66-year-old woman affected by polymyalgia rheumatica who initially did not fulfill the criteria for any known hematological condition (abnormal FLC ratio, increased level of FLC, no monoclonal heavy chain, fewer than 10% monoclonal plasma cells in the bone marrow). Interestingly, urine analysis demonstrated positivity to Bence-Jones protein, a hallmark already described by various authors.5, 6 Suddenly, the patient developed proteinuria within the nephrotic range (3.5 g per 24 h) and underwent renal biopsy. Despite the extremely low level of λ-FLC (28.24 mg/l), the histological study revealed renal AL amyloidosis (Figures 1a and b). Finally, these deposits were typified by electron microscopy (Figures 1c and d) with immunogold labeling.8 A subsequent bone marrow biopsy and electrophoresis confirmed the presence of monoclonal light chain component without morphological evidence of clonal plasma cells. Interestingly, bone marrow was focally replaced by the presence of metastatic carcinomatous cells from occult lobular breast carcinoma (Figure 1e). Moreover, the vessels’ walls of the bone marrow and breast tissue, collected to perform cancer diagnosis, displayed positivity to Congo red stain (Figure 1f). The systemic involvement made our case partially divergent from the benign course of the entity described by previous series,5, 6 although those could be applied to our patient because of our current limitations in detecting low levels of clonal cells using immunohistochemistry and flow cytometry on bone marrow specimens.9 It is interesting to underline the disproportion between the slight FLC component and the impressive systemic involvement by amyloid deposition, a phenomenon that could be differently interpreted. On one hand, there may be another pathophysiological process that promotes the development of disseminated amyloidosis, and we are actually unable to detect it; on the other hand, a MGUS with this kind of behavior may have a more aggressive course and a potential poor outcome. In this second hypothesis, a further update of the entity definition may be required, supported by other analog case reports. A multidisciplinary approach with different techniques (high sensitivity immunofluorescence and specific immunogold electron microscopy) was also used to typify amyloidosis, highlighting the difficulty in solving these kinds of diagnostic issues. Furthermore, the clinical features of our disseminated amyloidosis were in agreement with a previous series in which such occult proliferations evoked exaggerated and unexpected systemic consequences.10 Moreover, in a first instance, the unusual association between breast cancer and amyloid deposition was suggestive of a serum amyloid A–type amyloidosis, a phenomenon already reported in literature,11 and then the positivity to λ antisera in immunofluorescence represented for us a surprisingly finding. Finally, our case was also particularly intriguing due to the possible link between renal and hematological disorders. In this context, our experience may add a further condition to Bridoux classification,3 improving clinical management of monoclonal-related renal diseases.

In immunoglobulin (Ig) light-chain (LC) (AL) amyloidosis, AL deposition translates into life-threatening cardiomyopathy. Clinical and experimental evidence indicates that soluble cardiotoxic LCs are themselves harmful for cells, by which they are internalized. Hypothesizing that interaction of soluble cardiotoxic LCs with cellular proteins contributes to damage, we characterized their interactome in cardiac cells. LCs were purified from patients with AL amyloidosis cardiomyopathy or multiple myeloma without amyloidosis (the nonamyloidogenic/noncardiotoxic LCs served as controls) and employed at concentrations in the range observed in AL patients' sera. A functional proteomic approach, based on direct and inverse coimmunoprecipitation and mass spectrometry, allowed identifying LC-protein complexes. Findings were validated by colocalization, fluorescence lifetime imaging microscopy (FLIM)-fluorescence resonance energy transfer (FRET), and ultrastructural studies, using human primary cardiac fibroblasts (hCFs) and stem cell-derived cardiomyocytes. Amyloidogenic cardiotoxic LCs interact in vitro with specific intracellular proteins involved in viability and metabolism. Imaging confirmed that, especially in hCFs, cardiotoxic LCs (not controls) colocalize with mitochondria and spatially associate with selected interactors: mitochondrial optic atrophy 1-like protein and peroxisomal acyl-coenzyme A oxidase 1 (FLIM-FRET efficiencies 11 and 6%, respectively). Cardiotoxic LC-treated hCFs display mitochondrial ultrastructural changes, supporting mitochondrial involvement. We show that cardiotoxic LCs establish nonphysiologic protein-protein contacts in human cardiac cells, offering new clues on the pathogenesis of AL cardiomyopathy.