Local vs. systemic pulmonary amyloidosis—impact on diagnostics and clinical management

Multifaceted pulmonary manifestations of amyloidosis: state-of-the-art update

INTRODUCTION

Amyloidosis, a polymeric deposition disease classified according to protein subtype, may have varied pulmonary manifestations. Its anatomic-radiologic phenotypes include nodular, cystic, alveolar-septal, and tracheobronchial forms. Clinical presentation may range from asymptomatic parenchymal nodules to respiratory failure from diffuse parenchymal infiltration or diaphragmatic deposition.

AREAS COVERED

In this review, we systematically describe the molecular subtypes of amyloidosis and their clinical and radiologic findings in the lungs as well as key extrapulmonary organ systems. We detail novel treatment approaches to systemic amyloidosis. We also discuss prognostic elements for each subtype. We identify key clinical scenarios where reaching a precise diagnosis can be complicated, and we offer insights on the varied presentations of pulmonary amyloidosis.

EXPERT OPINION

Pulmonary amyloidosis is often difficult to diagnose as it may mimic other conditions, including fibrotic interstitial lung diseases and neoplasms, or can co-exist with certain connective tissue diseases. Despite some early artificial intelligence screening tools, improved familiarity among clinicians can aid in the more accurate and timely diagnosis of this multidimensional clinical entity. We additionally believe that multidisciplinary clinical pathwaysto diagnose and/or treat pulmonary amyloidosis have the potential to improve awareness, decrease diagnostic delay, and further elucidate knowledge on this multifaceted disease.

Amyloidosis in Childhood: A Review of Clinical Features and Comparison with Adult Forms

Amyloidosis is a rare multisystem disorder characterized by extracellular accumulation of insoluble fibrils in various organs and tissues. The most common subtype in the pediatric population is systemic reactive amyloidosis, typically developing secondary to chronic inflammatory conditions and resulting in deposition of serum amyloid A protein in association with apolipoprotein HDL3. Clinical presentation is highly variable and is mostly influenced by specific organs involved, precursor protein type, and extent of amyloid deposition, often closely reflecting clinical features of the underlying disease. The most critical determinants of prognosis are cardiac and renal involvement. Diagnosis of amyloidosis is confirmed by tissue biopsy, which remains the gold standard, followed by precise amyloid fibril typing. The primary therapeutic approach is directed towards controlling underlying disease and reducing serum levels of precursor proteins to prevent further amyloid deposition. This study aims to highlight the main clinical characteristics of amyloidosis with onset in childhood, emphasizing the key differences compared to adult form.

Tracheobronchial Amyloidosis Causing Left Lung Collapse: A Case Report

Tracheobronchial amyloidosis is a rare condition characterized by the deposition of amyloid proteins in the trachea and bronchi, leading to significant respiratory symptoms such as chronic mucoid, cough, dyspnea, and recurrent respiratory infections. We present the case of a 61-year-old individual who developed tracheobronchial amyloidosis, which poses a diagnostic challenge due to its clinical and radiological resemblance to other pulmonary disorders, including chronic bronchitis. Histologically, tracheobronchial amyloidosis is characterized by the presence of amyloid deposits confirmed by Congo red staining, which shows apple-green birefringence under polarized light. Further confirmation can be obtained through electron microscopy, revealing non-branching fibrils. This report explores the clinical presentation, diagnostic challenges, and management of tracheobronchial amyloidosis. Therapeutic interventions may include bronchoscopic procedures to remove obstructive amyloid deposits and systemic treatments such as chemotherapy or immunotherapy to address the underlying amyloid process, aiming to improve patient outcomes and quality of life.

A Case of Solitary Amyloid Lung Nodule Treated With Surgery

Primary or light-chain (AL) (lambda) amyloidosis is a rare systemic disorder that is characterized by the misfolding of autologous proteins and the extracellular deposition of abnormally folded proteins composed of immunoglobulin light chains, often caused by plasma cell dyscrasias. We present a unique case of a 57-year-old female with multiple comorbidities, including extensive smoking history and chronic kidney disease, who was incidentally discovered to have a left upper lobe lung nodule on a chest X-ray prompted by complaints of shortness of breath. The patient underwent biopsy of the lung nodule, and by utilizing the gold standard diagnostic technique of a Congo red stain, positive test results confirmed the diagnosis of AL amyloidosis. However, additional investigations, including bone marrow and fat pad biopsies, were negative for plasma cell dyscrasias. The patient subsequently underwent a wedge resection of the nodule, and a follow-up positron emission tomography-computed tomography (PET-CT) scan showed only post-surgical changes in the left upper lobe of the lung without evidence of disease progression or systemic involvement. Given the asymptomatic and multisystem symptomology of most cases, treatment options for AL amyloidosis are individualized. This case discusses pulmonary nodular AL amyloidosis and highlights the diagnostic and treatment options for this disorder.

Nodular pulmonary amyloidosis diagnosed by ultrasound-guided percutaneous needle biopsy

Pulmonary amyloidosis is characterized by extracellular deposition of fibrous protein called amyloid in the lungs and has three subtypes: nodular, diffuse, and tracheobronchial amyloidosis. Pulmonary nodular amyloidosis can mimic other lung diseases including infectious diseases, metastatic lung tumors, sarcoidosis, and pulmonary hyalinizing granuloma. A biopsy of the lesion is essential for a definitive diagnosis. Herein, we report the case of a 66-year-old man who presented for shortness of breath on exertion and was diagnosed with nodular pulmonary amyloidosis on ultrasound-guided percutaneous needle biopsy. A chest X-ray and computed tomography (CT) revealed bilateral slowly growing multiple calcified pulmonary nodules and cavities. Malignancy was suspected based on 18F-fluoro-deoxyglucose (18F-FDG) positron emission tomography/CT (PET/CT) images. An ultrasound-guided percutaneous needle biopsy was performed, and histopathologic examination of the lesion confirmed nodular pulmonary amyloidosis. This case highlights the importance of considering nodular pulmonary amyloidosis in the differential diagnosis of pulmonary nodules with increased uptake of 18F-FDG on PET/CT and the utility of ultrasound-guided needle biopsy in the definitive diagnosis.

Clinical spectrum of Transthyretin amyloidogenic mutations among diverse population origins

PURPOSE

Coding mutations in the Transthyretin (TTR) gene cause a hereditary form of amyloidosis characterized by a complex genotype-phenotype correlation with limited information regarding differences among worldwide populations.

METHODS

We compared 676 diverse individuals carrying TTR amyloidogenic mutations (rs138065384, Phe44Leu; rs730881165, Ala81Thr; rs121918074, His90Asn; rs76992529, Val122Ile) to 12,430 non-carriers matched by age, sex, and genetically-inferred ancestry to assess their clinical presentations across 1,693 outcomes derived from electronic health records in UK biobank.

RESULTS

In individuals of African descent (AFR), Val122Ile mutation was linked to multiple outcomes related to the circulatory system (fold-enrichment = 2.96, p = 0.002) with the strongest associations being cardiac congenital anomalies (phecode 747.1, p = 0.003), endocarditis (phecode 420.3, p = 0.006), and cardiomyopathy (phecode 425, p = 0.007). In individuals of Central-South Asian descent (CSA), His90Asn mutation was associated with dermatologic outcomes (fold-enrichment = 28, p = 0.001). The same TTR mutation was linked to neoplasms in European-descent individuals (EUR, fold-enrichment = 3.09, p = 0.003). In EUR, Ala81Thr showed multiple associations with respiratory outcomes related (fold-enrichment = 3.61, p = 0.002), but the strongest association was with atrioventricular block (phecode 426.2, p = 2.81 × 10- 4). Additionally, the same mutation in East Asians (EAS) showed associations with endocrine-metabolic traits (fold-enrichment = 4.47, p = 0.003). In the cross-ancestry meta-analysis, Val122Ile mutation was associated with peripheral nerve disorders (phecode 351, p = 0.004) in addition to cardiac congenital anomalies (fold-enrichment = 6.94, p = 0.003).

CONCLUSIONS

Overall, these findings highlight that TTR amyloidogenic mutations present ancestry-specific and ancestry-convergent associations related to a range of health domains. This supports the need to increase awareness regarding the range of outcomes associated with TTR mutations across worldwide populations to reduce misdiagnosis and delayed diagnosis of TTR-related amyloidosis.

Imaging in pleural amyloidosis: A diagnostic challenge

Pleural amyloidosis does not present with specific imaging findings and is difficult to diagnose unless pleural biopsy is performed. However, distinguishing pleural amyloidosis from malignant disease is important and biopsy should be performed wherever possible to establish a treatment plan as early as possible.

Pulmonary manifestations of amyloidosis

Amyloidosis is caused by abnormal protein deposition in various tissues, including the lungs. Pulmonary manifestations of amyloidosis may be categorized by areas of involvement, such as parenchymal, large airway and pleural involvement. We describe four distinct manifestations of amyloidosis involving the lung and review their clinical, radiological and pathological features and summarize the evidence for treatment in each of these presentations. We describe alveolar-septal amyloidosis, cystic amyloid lung disease, endobronchial amyloidosis and pleural amyloidosis.

Noninvasive Diagnostics of Renal Amyloidosis: Current State and Perspectives

Amyloidoses is a group of diseases characterized by the accumulation of abnormal proteins (called amyloids) in different organs and tissues. For systemic amyloidoses, the disease is related to increased levels and/or abnormal synthesis of certain proteins in the organism due to pathological processes, e.g., monoclonal gammopathy and chronic inflammation in rheumatic arthritis. Treatment of amyloidoses is focused on reducing amyloidogenic protein production and inhibition of its aggregation. Therapeutic approaches critically depend on the type of amyloidosis, which underlines the importance of early differential diagnostics. In fact, the most accurate diagnostics of amyloidosis and its type requires analysis of a biopsy specimen from the disease-affected organ. However, absence of specific symptoms of amyloidosis and the invasive nature of biomaterial sampling causes the late diagnostics of these diseases, which leads to a delayed treatment, and significantly reduces its efficacy and patient survival. The establishment of noninvasive diagnostic methods and discovery of specific amyloidosis markers are essential for disease detection and identification of its type at earlier stages, which enables timely and targeted treatment. This review focuses on current approaches to the diagnostics of amyloidoses, primarily with renal involvement, and research perspectives in order to design new specific tests for early diagnosis.

Supportive Care and Symptom Management for Patients With Immunoglobulin Light Chain (AL) Amyloidosis

Immunoglobulin light chain (AL) amyloidosis is a disorder of clonal plasma cells characterized by deposition of amyloid fibrils in a variety of tissues, leading to end-organ injury. Renal or cardiac involvement is most common, though any organ outside the central nervous system can develop amyloid deposition, and symptomatic presentations may consequently vary. The variability and subtlety of initial clinical presentations may contribute to delayed diagnoses, and organ involvement is often quite advanced and symptomatic by the time a diagnosis is established. Additionally, while organ function can improve with plasma-cell-directed therapy, such improvement lags behind hematologic response. Consequently, highly effective supportive care, including symptom management, is essential to improve quality of life and to maximize both tolerance of therapy and likelihood of survival. Considering the systemic nature of the disease, close collaboration between clinicians is essential for effective management.

Multidisciplinary supportive care in systemic light chain amyloidosis

The immunoglobulin light-chain amyloidosis is a multisystemic disease which manifests by damage to the vital organs by light chain-derived amyloid fibril. Traditionally, the treatment has been directed to the underlying plasma cell clone with or without high dose chemotherapy followed by autologous stem cell transplantation using melphalan based conditioning. Now with the approval of highly tolerable anti-CD38 monoclonal antibody daratumumab based anti-plasma cell therapy in 2021, high rates of hematologic complete responses are possible even in patients who are otherwise deemed not a candidate for autologous stem cell transplantation. However, despite the progress, there remains a limitation in the strategies to improve symptoms particularly in patients with advanced cardiac involvement, those with nephrotic syndrome and autonomic dysfunction due to underlying systemic AL amyloidosis. The symptoms can be an ordeal for the patients and their caregivers and effective strategies are urgently needed to address them. The supportive care is aimed to counteract the symptoms of the disease and the effects of the treatment on involved organs’ function and preserve patients’ quality of life. Here we discuss multidisciplinary approach in a system-based fashion to address the symptom management in this dreadful disease. In addition to achieving excellent anti-plasma cell disease control, using treatment directed to remove amyloid from the vital organs can theoretically hasten recovery of the involved organs thereby improving symptoms at a faster pace. Ongoing phase III clinical trials of CAEL-101 and Birtamimab will address this question.

Local Insulin-Derived Amyloidosis Model Confronted with Silymarin: Histological Insights and Gene Expression of MMP, TNF-α, and IL-6

Amyloidosis is a heterogeneous group of protein deposition diseases associated with the presence of amyloid fibrils in tissues. Analogs of insulin that are used for treating diabetic patients (including regular insulin) can form amyloid fibrils, both in vitro and in vivo as reported in patients. The main purpose of this study was the induction of localized insulin-generated amyloidosis and the observation of silymarin effects on this process. In order to obtain amyloid structures, regular insulin was incubated at 37 °C for 24 h. Congo red absorbance and transmission electron microscopy images validated the formation of amyloid fibrils. Those fibrils were then injected subcutaneously into rats once per day for 6, 12 or 18 consecutive days in the presence or absence of silymarin, and caused development of firm waxy masses. These masses were excised and stained with Hematoxylin and Eosin, Congo red and Thioflavin S. Histological examination showed adipose cells and connective tissue in which amyloid deposition was visible. Amyloids decreased in the presence of silymarin, and the same effect was observed when silymarin was added to normal insulin and injected subsequently. Furthermore, plasma concentrations of MMP2, TNF-α, and IL-6 inflammatory factors were measured, and their gene expression was locally assessed in the masses by immunohistochemistry. All three factors increased in the amyloidosis state, while silymarin had an attenuating effect on their plasma levels and gene expression. In conclusion, we believe that silymarin could be effective in counteracting insulin-generated local amyloidosis.

A central role for amyloid fibrin microclots in long COVID/PASC: origins and therapeutic implications

Post-acute sequelae of COVID (PASC), usually referred to as 'Long COVID' (a phenotype of COVID-19), is a relatively frequent consequence of SARS-CoV-2 infection, in which symptoms such as breathlessness, fatigue, 'brain fog', tissue damage, inflammation, and coagulopathies (dysfunctions of the blood coagulation system) persist long after the initial infection. It bears similarities to other post-viral syndromes, and to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Many regulatory health bodies still do not recognize this syndrome as a separate disease entity, and refer to it under the broad terminology of 'COVID', although its demographics are quite different from those of acute COVID-19. A few years ago, we discovered that fibrinogen in blood can clot into an anomalous 'amyloid' form of fibrin that (like other β-rich amyloids and prions) is relatively resistant to proteolysis (fibrinolysis). The result, as is strongly manifested in platelet-poor plasma (PPP) of individuals with Long COVID, is extensive fibrin amyloid microclots that can persist, can entrap other proteins, and that may lead to the production of various autoantibodies. These microclots are more-or-less easily measured in PPP with the stain thioflavin T and a simple fluorescence microscope. Although the symptoms of Long COVID are multifarious, we here argue that the ability of these fibrin amyloid microclots (fibrinaloids) to block up capillaries, and thus to limit the passage of red blood cells and hence O2 exchange, can actually underpin the majority of these symptoms. Consistent with this, in a preliminary report, it has been shown that suitable and closely monitored 'triple' anticoagulant therapy that leads to the removal of the microclots also removes the other symptoms. Fibrin amyloid microclots represent a novel and potentially important target for both the understanding and treatment of Long COVID and related disorders.

Pulmonary amyloidosis and multiple myeloma mimicking lymphoma in a patient with Sjogren’s syndrome: A case report

BACKGROUND

Sjogren’s syndrome (SS), which affect salivary gland function, is an autoimmune disease. SS may involve extraglandular organs. Approximately 10 to 20 percent of SS patients have clinically significant lung disease, but presentation of pulmonary amylodosis is extremly rare. The incidence of benign monoclonal gammopathy in SS patients is high, but multiple myeloma is rare. No case involving the simultaneous occurrence of two rare diseases, pulmonary amyloidosis and multiple myeloma, in the same patient with SS has been reported so far.

CASE SUMMARY

A 41-year-old male patient was referred to our hematology department due to incidentally detected gastric plasmacytoma. He had been diagnosed with SS four years earlier. Multiple miliary nodules, ground glass opacity in both lung fields, and enlargement of both inguinal lymph nodes was observed on chest and abdomen computer tomography. Based on the pathological findings of lung and lymph node biopsied specimens, the patient was diagnosed with pulmonary amyloidosis and multiple myeloma. Pulmonary amyloidosis and multiple myeloma associated with SS has rarely been reported.

CONCLUSION

This is an extremely rare case of simultaneous pulmonary amyloidosis and multiple myeloma in the same patient with SS.

Case Report: Management of Primary Tracheobronchial Light Chain Amyloidosis in a Patient With Biclonal Gammopathy Using a Systemic Bortezomib-Based Regimen

Primary tracheobronchial light chain (AL) amyloidosis is a rare and heterogeneous disease characterized by the buildup of amyloid deposits in the airway mucosa. Although its treatment remains challenging, the current view is that the localized form can be treated conservatively due to its slow progression. While radiotherapy has proven effective in treating localized form of the disease, some patients do not respond to local treatment and continue to experience poor quality of life, highlighting the need to explore additional treatment strategies. In this report, we discuss a case of primary tracheobronchial AL amyloidosis with biclonal gammopathy (IgA κ and IgG κ) in a 46-year-old man who was transferred to our hospital due to dyspnea progression over the preceding 3 years. Chest computed tomography revealed irregular tracheobronchial stenosis with wall thickening, and histological examination of the bronchial biopsies confirmed the diagnosis of endobronchial AL amyloidosis. Owing to the poor effect of radiation therapy and treatments for improving airway patency, he was treated with a systemic chemotherapy regimen [cyclophosphamide-bortezomib-dexamethasone (CyBorD)]. We observed substantial improvements in his dyspnea, highlighting the potential of systemic therapy to improve quality of life of patients with tracheobronchial AL amyloidosis. However, the long-term pathological changes associated with local bronchial lesions require further investigation.

The amyloid proteome: a systematic review and proposal of a protein classification system

Amyloidosis is a disease caused by pathological fibril aggregation and deposition of proteins in different tissues and organs. Thirty-six fibril-forming proteins have been identified. So far, proteomic evaluation of amyloid focused on the detection and characterization of fibril proteins mainly for diagnostic purposes or to find novel fibril-forming proteins. However, amyloid deposits are a complex mixture of constituents that show organ-, tissue-, and amyloid-type specific patterns, that is the amyloid proteome. We carried out a comprehensive literature review on publications investigating amyloid via liquid chromatography coupled to tandem mass spectrometry, including but not limited to sample preparation by laser microdissection. Our review confirms the complexity and dynamics of the amyloid proteome, which can be divided into four functional categories: amyloid proteome-category 1 (APC1) includes exclusively fibrillary proteins found in the patient; APC2 includes potential fibril-forming proteins found in other types of amyloid; and APC3 and APC4 summarizes non-fibril proteins-some being amyloid signature proteins. Our categorization may help to systemically explore the nature and role of the amyloid proteome in the manifestation, progression, and clearance of disease. Further exploration of the amyloid proteome may form the basis for the development of novel diagnostic tools, thereby enabling the development of novel therapeutic targets.

MALDI mass spectrometry imaging unravels organ and amyloid-type specific peptide signatures in pulmonary and gastrointestinal amyloidosis

PURPOSE

Amyloidosis is a disease group caused by pathological aggregation and deposition of peptides in diverse tissue sites. Recently, matrix-assisted laser desorption/ionization mass spectrometry imaging coupled with ion mobility separation (MALDI-IMS MSI) was introduced as a novel tool to identify and classify amyloidosis using single sections from formalin-fixed and paraffin-embedded cardiac biopsies. Here, we tested the hypothesis that MALDI-IMS MSI can be applied to lung and gastrointestinal specimens.

EXPERIMENTAL DESIGN

Forty six lung and 65 gastrointestinal biopsy and resection specimens with different types of amyloid were subjected to MALDI-IMS MSI. Ninety three specimens included tissue areas without amyloid as internal negative controls. Nine cases without amyloid served as additional negative controls.

RESULTS

Utilizing a peptide filter method and 21 known amyloid specific tryptic peptides we confirmed the applicability of a universal peptide signature with a sensitivity of 100% and a specificity of 100% for the detection of amyloid deposits in the lung and gastrointestinal tract. Additionally, the frequencies of individual m/z-values of the 21 tryptic marker peptides showed organ- and tissue-type specific differences.

CONCLUSIONS AND CLINICAL RELEVANCE

MALDI-IMS MSI adds a valuable analytical approach to diagnose and classify amyloid and the detection frequency of individual tryptic peptides is organ-/tissue-type specific.

Pulmonary amyloidosis mimicking interstitial lung disease and malignancy - A case series with a review of a pulmonary patterns

BACKGROUND

Amyloidosis is an uncommon condition, which results from accumulation of misfolded extracellular insoluble protein in tissues and organs of the body, causing its damage and dysfunction. Histologically, after staining with Congo red, the amyloid deposits show an apple-green birefringence under polarized light microscope. Amyloidosis can affect all organ systems and is classified into hereditary or acquired, localized or systemic. Respiratory involvement occurs in 50% of the patients with amyloidosis and it may take tracheobronchial, nodular parenchymal, diffuse alveolar septal and lymphatic forms.

METHODS

We report four cases of pulmonary amyloidosis. A female patient with localized form of tracheobronchial and nodular parenchymal pulmonary amyloidosis, which was initially misdiagnosed as sarcoidosis. A male patient who was referred to our department for further evaluation of multiple tumors in lungs accompanied by mediastinal lymphadenopathy, liver and peritoneal tumors. A male patient with suspect of lung malignancy. A male patient with diagnosed idiopathic pulmonary fibrosis and the possibility of malignancy.

RESULTS

All the diagnoses were established by demonstration of amyloid protein in tissue specimens obtained in transbronchial or open lung biopsies.

CONCLUSIONS

Due to its nonspecific clinical and radiological findings, amyloidosis can often mimic other diseases and should be considered as one of the differential diagnoses. In order to confirm the diagnosis, proving the presence of amyloid deposition with positive Congo red staining in respiratory specimen is mandatory.

Systemic AL amyloidosis presenting with diffuse alveolar septal involvement and respiratory failure: a case report and review of the literature

Background

Amyloidosis is the extracellular deposition of amyloid fibril protein in any tissue or organ. The clinical manifestations of pulmonary amyloidosis are variable and without specific symptoms. We report a rare case of diffuse alveolar septal amyloidosis which is an extremely rare pattern of involvement, with a very poor prognosis, to improve our understanding of the disease.

Case presentation

A 27-year-old man complained of shortness of breath and cyanosis. High-resolution computed tomography revealed diffuse ground-glass opacifications with interlobular septal thickening in both lungs. The immune-histochemistry showed monoclonal lambda light chains. This case also showed nephrotic syndrome and cardiac arrhythmia, suggesting an involvement of the kidney and the heart. Diagnosis: The diagnosis was finally established by tru-cut transthoracic sonar guided lung biopsy (TSLB), and histological examination revealed Congo red-positive amorphous eosinophilic deposits in the alveolar sept. Interventions: The patient was admitted to a respiratory intensive care unit and put on non-invasive ventilation, then discharged on domiciliary oxygen therapy, and started treatment with chemotherapy melphalan 2 mg daily plus prednisone 60 mg daily immediately after the result of histopathology. Outcomes: Three months after treatment, dyspnea and hypoxemia improved, and he continued treatment. The patient was in a good clinical condition after 10 months of follow-up, but he died suddenly.

Conclusion

As it is difficult to distinguish diffuse alveolar septal amyloidosis from other interstitial and granulomatous lung diseases because of their similar symptoms and imaging findings, thus, transthoracic sonar guided lung biopsy and histological examination is very important in the diagnosis of diffuse alveolar septal amyloidosis.

Localized immunoglobulin light chain amyloidosis: Novel insights including prognostic factors for local progression

In localized light chain amyloidosis (locAL), amyloidogenic light chains (aLC) are produced and deposited locally by a B-cell clone. We present 293 patients with immunohistochemically confirmed locAL. Lung (nodular pulmonary) with 63 patients was the most involved organ. The aLC was λ in 217 cases (κ:λ ratio 1:3). A local B-cell clone was identified in 30% of cases. Sixty-one (21%) had a concomitant autoimmune disorder (cAD). A monoclonal component (MC) were present in 101 (34%) patients and were more frequent in subjects with cAD (51% vs 34%; P = .03). Cigarette smoking was more prevalent in lung locAL (54% vs 37%; P = .018). After a median follow-up of 44 months, 16 patients died and 5- and 10-years locAL progression-free survival (PFS) were 62% and 44%. Interestingly, locAL-PFS was shorter among patients with an identified clonal infiltrate at amyloid deposition site (40 vs 109 months; P = .02) and multinuclear giant cells and/or an inflammatory infiltrate resulted in longer locAL-PFS in lung involvement (65 vs 42 months; P = .01). However, no differences in locAL PFS were observed in patients with cAD, a MC and involved organ site. Treatment was administered in 163 (54%) patients and was surgical in 135 (46%). Median locAL-PFS after first treatment was 56 months. Responders had longer locAL-PFS (78 vs 17 months; P < .001). Three patients with lung locAL and a MC were diagnosed as systemic AL amyloidosis at follow-up. In summary, locAL pathogenesis seems to be heterogeneous and the clonal infiltrate leads local progression.

Amyloidosis of the respiratory system: 16 patients with amyloidosis initially diagnosed ante mortem by pulmonologists

Background

Ante mortem diagnosis of amyloidosis of the respiratory system is rare. Few data are available regarding clinical presentation, precursor proteins, diagnostic procedures, comorbidities, complications, and outcome. We assessed clinical features of a series of patients with amyloidosis of the respiratory system in two Japanese centres.

Methods

Medical records of 16 patients with amyloidosis of the respiratory system were retrospectively analysed. Amyloid was diagnosed by polarisation microscopy using Congo red-stained tissue specimens and classified immunohistochemically.

Results

Median patient age was 71 years, and median follow-up period was 5 years. Immunoglobulin light-chain (AL)-λ amyloidosis was found in eight and AL-κ in five patients. Two patients harboured wild-type transthyretin and one harboured serum amyloid A-derived amyloid. Five different forms of amyloidosis of the respiratory system were observed: nodular pulmonary amyloidosis (seven patients), diffuse alveolar-septal amyloidosis (five), mediastinal lymph node amyloidosis (three), tracheobronchial amyloidosis (one), and pleural amyloidosis (one). One patient had diffuse alveolar-septal amyloidosis and mediastinal lymph node amyloidosis. Three of five patients with diffuse alveolar-septal amyloidosis were diagnosed by transbronchial lung biopsy as having concurrent diffuse alveolar haemorrhage or pneumocystis pneumonia. Two of three patients with mediastinal lymph node amyloidosis were diagnosed by endobronchial ultrasound-guided transbronchial needle aspiration.

Conclusions

Not only nodular pulmonary amyloidosis, diffuse alveolar-septal amyloidosis, and tracheobronchial amyloidosis but also mediastinal lymph node amyloidosis and pleural amyloidosis should be considered in the differential diagnosis of amyloidosis of the respiratory system. Useful diagnostic methods include transbronchial lung biopsy for diffuse alveolar-septal amyloidosis and endobronchial ultrasound-guided transbronchial needle aspiration for mediastinal lymph node amyloidosis.

Not only nodular, diffuse alveolar-septal and tracheobronchial amyloidosis but also mediastinal lymph node and pleural amyloidosis should be considered in the differential diagnosis of amyloidosis of the respiratory systemhttps://bit.ly/2ZfZcxo

Atypical primary pulmonary amyloidosis: A rare case report

RATIONALE

Pulmonary amyloidosis is a rare respiratory disease characterized by amyloid deposition in the lungs. The clinical manifestations of pulmonary amyloidosis are variable and without specific symptoms.

PATIENT CONCERNS

We report a rare case of tracheobronchial amyloidosis to improve our understanding of the disease.

DIAGNOSES

The diagnosis of tracheobronchial amyloidosis was finally established by transbronchoscopic lung biopsy and histological examination.

INTERVENTIONS

The patient significantly improved with methylprednisolone sodium succinate for injection (40 mg/day) for 5 days and low-dose oral prednisone for 10 days.

OUTCOMES

After treatment, discomfort, such as cough, stridor, dyspnea, and chest tightness, disappeared, and he was discharged. The patient was in good clinical condition after 8 months of follow-up.

CONCLUSION

This case clearly shows that it is difficult to distinguish tracheobronchial amyloidosis from other diseases with manifestations of cough, dyspnea and chest tightness because of their similar symptoms and imaging findings. Thus, the role of transbronchoscopic lung biopsy and histological examination in the diagnosis of tracheobronchial amyloidosis is very important.

Pulmonary nodules associated with pulmonary embolism: A rare and misleading presentation of amyloidosis

Amyloidosis is a rare disease especially the localized form involving pulmonary parenchyma. We report the case of a 74 years old woman who presented with chest pain and dyspnoea. CT scan showed pulmonary embolism and bilateral nodules. Laboratory examinations highlighted circulating Kappa IgM. 18F-FDG PET/CT showed intense activity of the nodules. Histological investigation supported the diagnosis of nodular pulmonary amyloidosis. There were no sign of systemic amyloidosis or autoimmune disease. No treatment was initiated: the patient remains asymptomatic after one year. Localized pulmonary amyloidosis related to MGUS was the most likely diagnosis. Malignancy, a differential diagnosis of pulmonary amyloidosis, must be excluded: histological examinations are overriding. Difference between systemic and localized amyloidosis conditions treatment and prognosis. This observation emphasizes the difficulty to establish the diagnosis of pulmonary nodular amyloidosis and the complex relationship between amyloidosis and thromboembolism.

CT features in amyloidosis of the respiratory system - Comprehensive analysis in a tertiary referral center cohort

PURPOSE

Amyloidosis of the respiratory system is rare and challenging since imaging findings have several more prevalent alternative diagnoses. We analyze and quantify chest CT findings in a large tertiary referral center patient cohort with confirmed amyloidosis of the respiratory system.

METHODS

67 patients with histology-proven amyloidosis of the respiratory system and with available chest CT scans were retrospectively enrolled (years 2002-2018): 41 patients with local pulmonary parenchymal, 20 with local tracheobronchial, and 6 with systemic amyloidosis. CT was scored for findings like mass lesions, nodules, cysts, lymphadenopathy, calcifications and pleural, interstitial and tracheobronchial manifestations. Clinical data and imaging findings' frequencies among patients with local pulmonary parenchymal and tracheobronchial amyloidosis were compared.

RESULTS

Patients with local pulmonary parenchymal amyloidosis were older (67 vs. 56 years; P = 0.013) and less frequently symptomatic for cough (24% vs. 70%; P = 0.018) and bronchopulmonal infections (7% vs. 55%; P < 0.001) than patients with tracheobronchial amyloidosis. Local pulmonary parenchymal amyloidosis showed higher frequency of mass-like lesions (41% vs. 0%; P = 0.002) and nodules (95% vs. 20%; P < 0.001, with 10 or more nodules in 56% vs. 0%; P < 0.001 and predominantly pleura-associated in 32% vs. 0%; P = 0.02). Tracheobronchial amyloidosis leads to wall thickening of the bronchi (100% vs. 5%; P < 0.001) and the trachea (70% vs. 2%; P < 0.001). Systemic amyloidosis went along with a predominant alveolar septal pattern in 4 out of 6 patients.

CONCLUSION

Patients with local pulmonary parenchymal amyloidosis differ significantly from patients with tracheobronchial amyloidosis regarding clinical data and CT findings' frequencies. Being familiar with radiological manifestations of all three respiratory amyloidosis distribution patterns is essential to accelerate the diagnosis.

The Pathology of Amyloidosis in Classification: A Review

BACKGROUND

The amyloidoses are a rare and heterogeneous group of disorders that are characterized by the deposition of abnormally folded proteins in tissues ultimately leading to organ damage. The deposits are mainly extracellular and are recognizable by their affinity for Congo red and their yellow-green birefringence under polarized light. Current classification of amyloid in medical practice is based on the amyloid protein type. To date, 36 proteins have been identified as being amyloidogenic in humans.

SUMMARY

in clinical practice, it is critical to distinguish between treatable versus non-treatable amyloidoses. Moreover, amyloidoses with a genetic component must be distinguished from the sporadic types and systemic amyloidoses must be distinguished from the localized forms. Among the systemic amyloidoses, AL continues to be the most common amyloid diagnosis in the developed world; other clinically significant types include AA, ALECT2, and ATTR. The latter is emerging as an underdiagnosed type in both the hereditary and wild-type setting. Other hereditary amyloidoses include AFib, several amyloidoses derived from apolipoproteins, AGel, ALys, etc. In a dialysis setting, systemic amyloid derived from β2 microglobulin (Aβ2M) should be considered, although a very rare hereditary variant has also been reported; several amyloidoses may be typically associated with aging and several iatrogenic types have also emerged. Determination of the amyloid protein type is imperative before specific therapy can be implemented and the current methods are briefly summarized. A brief overview of the target organ involvement by amyloid type is also included. Key Messages: (1) Early diagnosis of amyloidosis continues to pose a significant challenge and requires the participation of many clinical and laboratory specialties. (2) Determination of the protein type is imperative before specific therapy can be implemented. (3) While mass spectrometry has emerged as the preferred method of amyloid typing, careful application of immune methods is still clinically useful but caution and experience, as well as awareness of the limitations of each method, are necessary in their interpretation. (4) While the spectrum of amyloidoses continues to expand, it is critical to distinguish between those that are currently treatable versus those that are untreatable and avoid causing harm by inappropriate treatment.

A case report of pulmonary amyloidosis recognized by detection of AA amyloid exclusively in alveolar macrophages

Amyloidosis is a rare condition in which tissue deposits of inert fibrillar protein result in organ damage and dysfunction. There are several types of amyloid fibrils. Some of the most common forms are AL (amyloid light chain) protein and AA (amyloid-associated) type of amyloid fibril protein. Pulmonary amyloidosis is relatively common but is usually asymptomatic. Thus, the diagnosis may be easily overlooked. A 78-year-old male with a history of multiple myeloma followed by systemic amyloidosis presented with abnormal chest CT showing diffuse interlobular thickening in the whole lung field with bilateral pleural effusion. Bronchoalveolar lavage and transbronchial biopsy were performed. Due to the patient's poor condition and hemorrhage, only one fragment was available from forceps biopsy. Histologically, there was no amyloid deposition in the lung parenchyma; however, some histiocytes showed eosinophilic granular contents which prompted us to perform additional staining. The cytoplasmic material turned to be positive with direct fast scarlet (DFS) staining and AA amyloid immunostaining. Similar macrophages with AA amyloid were also found in the bronchoalveolar fluid. We experienced a case with AA amyloidosis affecting the lung diagnosed by the presence of intracytoplasmic amyloid in alveolar macrophages. The microscopic changes were so subtle that they may be overlooked. Recognition of amyloid deposition in alveolar macrophages may be an important clue to diagnose pulmonary amyloidosis. Such finding is of particular significance in the small-sized specimens, such as biopsies and cytologic smears.

Supportive Care in AL Amyloidosis

Immunoglobulin light-chain (AL) amyloidosis is a systemic disease characterized by the production and deposition of light chain-derived amyloid fibrils in different organs. Prompt treatment directed to the underlying plasma cell clone is crucial in order to achieve a rapid, deep and durable hematologic response. The decrease in the production of the amyloidogenic light chains is a required condition to obtain the organ response, which is commonly delayed. Meanwhile, supportive treatment is aimed to maintain quality of life of these patients and preserve their involved organs' function. From simple measures, such as salt restriction or compressive stockings, to very complex interventions, such as heart transplantation in very selected patients with isolated severe cardiac involvement, this supportive care is essential and has to be necessarily included in the multidisciplinary management of this disease.

Lower respiratory tract amyloidosis: Presentation, survival and prognostic factors. A multicenter consecutive case series

Lower-respiratory-tract (LRT) amyloidosis has rarely been investigated. Our study presents characteristics, outcomes and survival of LRT amyloidosis. This multicenter retrospective study, from 1995 to 2017, included 73 patients with amyloidosis and LRT involvement. Respiratory patterns were: tracheobronchial (n = 17), nodular (n = 10), interstitial (n = 14) or composite (several respiratory involvements, n = 32). Interstitial and composite patterns were associated with multi-organ amyloidosis (n = 37, 80%) while tracheobronchial and nodular patterns were associated with organ-limited amyloidosis (n = 21, 78%). Amyloid light chain (AL) amyloidosis was diagnosed in 43 patients (59%), mainly of lambda type (n = 33, 77%). Smokers' proportion was higher in tracheobronchial (71%) and nodular (90%) patterns than in interstitial (14%) and composite (34%) patterns. The B-cell neoplasms involved 15 patients (21%), solid neoplasms 8 (11%), connective tissue diseases 8 (11%) and multiple myeloma 6 (8%). The B-cell and solid neoplasms were most prevalent in nodular pattern. Median follow-up was 4.4 years (2.2-8.9). Twenty-four patients died, mostly from respiratory infection. Survival at 1, 5, 10 years was respectively 88%, 70% and 54% for multi-organ amyloidosis, 96%, 89% and 69% for organ-limited amyloidosis (P = .125). Tracheobronchial and nodular patterns survival was better than in other respiratory patterns (P = .039). Death risk factors (multivariate analysis) were: cardiac localization (hazard-ratio [HR] 4.3 [95% confidence interval 1.6-11.5]; P = .004), age (HR 2.1 [1.2-3.7]; P = .008) and dyspnea at diagnosis (HR 4.0 [1.3-12.3]; P = .014). Various LRT amyloidosis patterns depend on smoking habits, organ-limited or multi-organ extension and comorbidities. They are associated with a different survival, which is also predicted by age, cardiac localization and dyspnea at presentation.