Wild-type transthyretin cardiac amyloidosis (ATTRwt-CA), previously known as senile cardiac amyloidosis: clinical presentation, diagnosis, management and emerging therapies

Transthyretin amyloid cardiomyopathy. Features of histological diagnosis: study design

Aim. To compare efficiency and specific features of transthyretin amyloid staining by different histological dyes and thus to assess their suitability for diagnostic purposes. Materials and methods. Samples of left and right heart ventricles were taken from patients over 70 years-old of both genders (n=10) with immunohistochemically verified transthyretin amyloidosis (ATTR). All samples were stained with Congo red, Alcian blue, toluidine blue and methylene violet. Results. Specificity and sensitivity of Congo red staining was comparable to those of immunohistochemical staining. For verification of amyloid presence after Congo red staining one could use fluorescent microscopy instead of polarization microscopy. It allows a more accurate diagnosis of amyloidosis. Confocal microscopy with spectral unmixing improves detection sensitivity of amyloid by elimination of background fluorescence of muscle tissue and autofluorescence of lipofuscin. Alcian blue staining gives the same result as Congo red. In addition, its less labor-intensive and free of false-positive and false-negative results caused by final processing of slide preparation. Toluidine blue and methylene violet develop metachromatic staining upon binding to transthyretin fibrils, likely due to specific biochemical features of these fibrils. Conclusion. The most reliable method for histochemical diagnosis of ATTR is the Congo red staining with subsequent analysis using fluorescence or confocal microscopy. For diagnostic screening, the use of Sodium sulphate-Alcian blue staining method is highly promising. Metachromatic stains are less effective for ATTR diagnosis.

Flexor tenosynovectomy in carpal tunnel syndrome as a screening tool for early diagnosis of amyloidosis

INTRODUCTION

Amyloidosis is a heterogeneous group of diseases that most often presents with advanced cardiac pathology. Another presentation of the disease can include symptoms consistent with carpal tunnel syndrome; however, the true incidence of amyloidosis in patients with carpal tunnel syndrome remains unclear.

METHODS

We performed a retrospective chart review on all patients who underwent an open carpal tunnel release, with tenosynovium biopsy by a single surgeon between 01/2000 and 12/2018. Samples were stored in formalin following hematoxylin-eosin or congo red staining. A total of 199 patients were excluded for incomplete records, and carpal tunnel release performed for traumatic or infectious etiologies. Histologic findings of the attending pathologist were examined and categorized as follows: amyloidosis, fibrous tissue, tenosynovitis/inflammation edematous, benign tenosynovium, and gout.

RESULTS

Exactly 898 open carpal tunnel releases were performed, and 699 patients were included for final analysis. In all patients, biopsies for histology with hematoxylin-eosin (HE) staining were taken; in those HE stains where amylogenic proteins were suspected (73 or 10.4%), a subsequent congo red staining was additionally performed which confirmed the diagnosis of amyloidosis in 10 patients (1.4% of the carpal tunnel procedures). Overall, 10 patients were identified and constituted 1.4% of all HE stains (n = 10/699) and 13.7% of all congo red stains (n = 10/73).

CONCLUSION

Our results suggest that the incidence of amyloidosis in the general CTS patient population may be as high as 1.4% with routine screening by synovial biopsy and the diagnosis should be considered as a potential cause. Level of Evidence: III, retrospective study.

Nuclear Imaging for the Diagnosis of Cardiac Amyloidosis in 2021

Cardiac amyloidosis is caused by the deposition of misfolded protein fibrils into the extracellular space of the heart. The diagnosis of cardiac amyloidosis remains challenging because of the heterogeneous manifestations of the disease. There are many different types of amyloidosis with light-chain (AL) amyloidosis and transthyretin (ATTR) amyloidosis being the most common types of cardiac amyloidosis. Endomyocardial biopsy is considered the gold standard for diagnosing cardiac amyloidosis and differentiating amyloid subtypes, but its use is limited because of the invasive nature of the procedure, with risks for complications and the need for specialized training and centers to perform the procedure. Radionuclide cardiac imaging has recently become the most commonly performed test for the diagnosis of ATTR amyloidosis but is of limited value for the diagnosis of AL amyloidosis. Positron emission tomography has been increasingly used for the diagnosis of cardiac amyloidosis and its applications are expected to expand in the future. Imaging protocols are under refinement to achieve better quantification of the disease burden and prediction of prognosis.

Anticoagulation with warfarin compared to novel oral anticoagulants for atrial fibrillation in adults with transthyretin cardiac amyloidosis: comparison of thromboembolic events and major bleeding

BACKGROUND

Atrial fibrillation (AF) is common in patients with transthyretin cardiac amyloidosis (ATTR-CA). The optimal strategy to prevent strokes in patients with ATTR-CA and AF is unknown.

OBJECTIVES

To compare outcomes in patients with ATTR-CA and AF treated with warfarin versus novel oral anticoagulants (NOACs).

METHODS

This study was a retrospective analysis of patients with ATTR-CA stratified by presence or absence of AF and anticoagulation therapy. The primary outcome included a time to event analysis for the combined outcomes of stroke, transient ischaemic attack (TIA), major bleed, or death.

RESULTS

Of 290 patients, 217 patients (74.8%) had AF. Of those with AF (n = 217), 78 (35.9%) patients received warfarin compared with 116 (53.5%) patients who received NOACs. There were 17 thrombotic events, all in those diagnosed with AF compared with none in the patients without AF (p = .01). Over a mean follow-up of 2.4 years (range 0.1-12) there was no difference in primary outcome between those with AF treated with warfarin compared with NOACs (p = .35).

CONCLUSION

Patient with ATTR-CA and AF are at increased risk for stroke compared to patients with ATTR-CA and without AF. Thrombotic events and major bleeds did not differ between those who received warfarin and NOACs.

Diagnosis and treatment of transthyretin-related amyloidosis cardiomyopathy

Transthyretin-related amyloidosis (ATTR) is a subgroup of amyloidosis that results from extracellular misassembled and toxic amyloid deposits affecting multiple organ systems, and cardiac tissues in particular. Because ATTR often presents as heart failure with preserved ejection fraction (HFpEF), it has been largely underdiagnosed. Once considered incurable with a grave prognosis, ATTR cardiomyopathy has seen the development of promising alternatives for diagnosis and treatment, with early diagnosis and treatment of ATTR cardiomyopathy highly beneficial due to its high mortality rate. For instance, diagnosing ATTR cardiomyopathy previously required a cardiac biopsy, but new modalities, such as cardiac magnetic resonance imaging and radionuclide bone scans, show promise in accurately diagnosing ATTR cardiomyopathy. Ongoing research and clinical trials have focused on identifying new treatments which primarily target amyloid fiber formation by inhibiting TTR gene expression, stabilizing the TTR tetramer, preventing oligomer aggregation, or affecting degradation of amyloid fibers. In this review, we describe the advances made in the diagnosis and treatment of ATTR in order to increase awareness of the disease and encourage a lower threshold for ATTR workup. Our review also highlights the need for improving the screening, diagnosis, and treatment guidelines for ATTR cardiomyopathy.

A case of unilateral shoulder joint hydrarthrosis with wild-type amyloidogenic transthyretin amyloidosis

Wild-type amyloidogenic transthyretin (ATTR) amyloidosis, known as systemic senile amyloidosis (SSA), is an age-related nonhereditary amyloidosis, which is known to cause cardiomyopathy and carpal tunnel syndrome (CTS). Herein, we report a case of unilateral hydrarthrosis with arthritis of the right shoulder joint in an 82-year-old Japanese housewife who has a seven year history of polyneuropathy due to an unknown aetiology. At first, her joint pain was thought to be caused by overuse of her right upper arm. Despite treatment with non-steroidal anti-inflammatory drugs (NSAIDs) and repeated arthrocentesis, her symptoms did not improve. She then visited our hospital, where magnetic resonance imaging (MRI) of her right shoulder suggested synovitis and hydrarthrosis. She also had an arthroscopic synovectomy of the right shoulder joint. The pathological testing revealed a diagnosis of non-specific arthritis with amyloidosis. After further pathological examination, wild-type ATTR was identified and she was diagnosed with senile amyloidosis.

Pulmonary light chain deposition disease: a case series and literature review

Background

Light chain deposition disease (LCDD) is a systemic disorder typically characterized by non-amyloid monoclonal immunoglobulin light chain deposition in tissues. LCDD is recognized as a multisystem disease, in which the kidneys and liver are often affected. However, it is rarely encountered as a localized pulmonary disease. This study set out to characterize the clinical manifestations and features of pulmonary light-chain deposition disease (PLCDD) by conducting a retrospective analysis of clinical data obtained from patients, with the aim of improving clinical understanding of PLCDD.

Methods

Data from inpatients diagnosed with PLCDD at Shanghai Pulmonary Hospital (Shanghai, China) between January 2010 and December 2018 were retrospectively collected and analyzed.

Results

A total of 4 PLCDD patients confirmed with PLCDD by pulmonary tissue biopsy were analyzed. All of the patients were female and were found by physical examination. Chest images of each patient’s lungs showed multiple cystic cavities with nodules. A history of Sjogren’s syndrome was present with 1 patient, 2 patients were diagnosed with Sjogren’s syndrome after surgery (including 1 diagnosed with Sjogren’s syndrome in the 8th year of follow up), and 3 patients had leukopenia. The longest follow-up period was 8 years. During the follow-up period, 2 patients developed pulmonary lesions (1 patient had an enlarged original cystic lesion in basal segment of right lower lobe 2 years after surgery, while the other developed new nodules 7 years after surgery).

Conclusions

PLCDD is characterized by multiple cystic changes with nodules in both lungs and can be easily complicated by lymphoid diseases such as Sjogren’s syndrome. The clinical symptoms cannot be characterized, and the diagnosis depends on lung biopsy.

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.

Hypoxia and Inflammation as a Consequence of β-Fibril Accumulation: A Perspective View for New Potential Therapeutic Targets

Amyloidoses are heterogeneous diseases that result from the deposition of toxic insoluble β-sheet fibrillar protein aggregates in different tissues. The cascade of molecular events leading to amyloidoses and to the related clinical manifestations is not completely understood. Nevertheless, it is known that tissue damage associated to this disease involves alteration of tissue architecture, interaction with cell surface receptors, inflammation elicited by the amyloid protein deposition, oxidative stress, and apoptosis. However, another important aspect to consider is that systemic protein massive deposition not only subverts tissue architecture but also determines a progressive cellular hypertrophy and dilation of the extracellular space enlarging the volume of the organ. Such an alteration increases the distance between cells and vessels with a drop in pO₂ that, in turn, causes both necrotic cell death and activation of the hypoxia transcription factor HIF-1α. Herewith, we propose the hypothesis that both cell death and hypoxia represent two important events for the pathogenesis of damage and progression of amyloidoses. In fact, molecules released by necrotic cells activate inflammatory cells from one side while binding to HIF-1α-dependent membrane receptors expressed on hypoxic parenchymal cells on the other side. This latter event generates a signaling cascade triggering NFκB activation and chronic inflammation. Finally, we also suggest that this scenario, once proved and detailed, might suggest important targets for new therapeutic interventions.