Transbronchial biopsies safely diagnose amyloid lung disease

Coexistence of Sjögren's syndrome and pulmonary nodular amyloidosis

There are very few cases in the literature on the coexistence of Sjögren's syndrome and pulmonary nodular amyloidosis being treated with rituximab. When nodules with central calcification and cystic lesions are seen on computed tomography, amyloid lung should be considered. Biopsy is recommended as it can be confused with malignancies. In this article, we present a 66-year-old female patient who has been followed up for Sjögren's syndrome for 26 years. Multiple cystic lesions with central calcification in the lung were detected and it was evaluated as amyloid nodule in the biopsy performed. The patient is being followed and is stable under rituximab treatment. Pulmonary noduler amyloidosis is very rare in Sjögren patients and there are very few cases where rituximab is used for treatment. We decided to publish in order to guide clinicians who will encounter similar cases.

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.

Pulmonary function tests reveal unrecognised lung dysfunction and have independent prognostic significance in patients with systemic AL amyloidosis

BACKGROUND

Lung involvement in AL amyloidosis is not very common, but post-mortem data and retrospective studies suggest it is likely underrecognized.

AIM

To perform a comprehensive evaluation of lung function with pulmonary function tests (PFTs) in patients with newly diagnosed AL amyloidosis.

METHODS

A prospective, non-interventional study of 139 consecutive patients with newly diagnosed AL amyloidosis.

RESULTS

PFTs indicated normal breathing physiology in 68% of patients, obstructive in 9% and restrictive in 23%; the latter was associated with worse survival (28.6 vs 76 months for obstructive/normal physiology, p = 0.002) and remained significant after adjustment for Mayo stage and abnormal chest-CT. Forced vital capacity <80% of predicted value, forced expiratory volume <80% of predicted value, and carbon monoxide diffusion capacity <70% were independently associated with poorer survival. Respiratory muscle strength (as assessed by maximal expiratory (Pe) and inspiratory (Pi) pressure) was affected in most patients (64% had Pi < 55% and 57% had Pe < 70% of predicted values). Pe% was an independent prognostic factor for survival (HR: 0.984 per 1% unit increase, p = 0.007).

CONCLUSIONS

Pulmonary dysfunction, as assessed with PFTs, is common and underrecognized in patients with systemic AL amyloidosis, with significant prognostic and potentially therapeutic implications, independent of the degree of cardiac dysfunction or chest-CT findings.

Transcriptomic analysis reveal the responses of dendritic cells to VDBP

BACKGROUND

Vitamin D binding protein (VDBP) is an essential plasma carrier protein, which plays possible roles in reproductive health, disease and so on. However, the effects of VDBP on immunity have not been fully studied and the pertinent literatures remain very limited.

OBJECTIVE

In this study, we introduced the exogenous VDBP into DC2.4 and established a stable DC2.4/VDBP cell line to explore the role of this gene in immunity.

METHODS

Dendritic cells (DCs), as the most effective antigen presenting cells (APC) found so far, are directly involved in regulating some innate immunity. In order to evaluate the biological role of VDBP in DCs, we stably overexpressed VDBP in DCs, and conducted Cell Counting Kit‑8 (CCK-8 kit) and flow cytometry to detect changes in cell function. CCK-8 kit was used to monitor the viability of DCs after gene overexpression, and flow cytometry was used to detect changes in cell cycle distribution and apoptosis. Subsequently, in order to reveal the mechanism of VDBP regulating DCs, we adopted RNA sequencing (RNA-seq).

RESULTS

CCK-8 results revealed VDBP successfully inhibited viability of DCs. Besides, we found that overexpression of this gene greatly promoted apoptosis and obviously altered the cell cycle distribution of DCs in G1 and G2 phases. Moreover, RNA-seq was carried out and 151 differently expression genes (DEGs) were obtained. In addition, gene differential expression analysis showed that most of them were uniformly enriched in immunity-related pathways.

CONCLUSION

These results indicated that VDBP greatly repressed proliferation, facilitated apoptosis and changed cell cycle in DCs via altering the expression levels of gene associated with their cellular immunity.

Pulmonary 99mTc-HMDP uptake correlates with restrictive ventilatory defects and abnormal lung reactance in transthyretin cardiac amyloidosis patients

BACKGROUND

Pulmonary involvement in individuals with transthyretin cardiac amyloidosis is unclear. The aim of this study was to quantify 99mTc-hydroxy methylene diphosphonate (HMDP) lung retention in hereditary transthyretin (ATTRv) cardiac amyloidosis patients and to relate tracer uptake intensity to pulmonary function and aerobic capacity.

METHODS

We prospectively enrolled 20 patients with biopsy-proven ATTRv cardiac amyloidosis and 20 control subjects. Cardiac involvement was confirmed by echocardiography and nuclear imaging using 99mTc-HMDP. Semi-quantitative analysis of the heart, rib and lung retention was assessed using a simple region of interest technique. Pulmonary function was evaluation by the means of whole-body plethysmography, diffusing capacity of the lung for carbon monoxide, forced oscillation technique and cardiopulmonary exercise testing.

RESULTS

Pulmonary tracer uptake estimated by lung to rib retention ratio was higher in ATTRv amyloidosis patients compared with control subjects: median 0.62 (0.55-0.69) vs 0.51 (0.46-0.60); p = 0.014. Analysis of relation between lung 99mTc-HMDP retention and pulmonary function parameters shown statistically significant correlations with total lung volume (% predicted), lung reactance (Xrs 5 Hz) and peak VO2, suggesting total lung capacity restriction impaired elastic properties of the lung and poor aerobic capacity.

CONCLUSION

Our study suggests that some grade of pulmonary retention of 99mTc-HMDP may occur in patients with cardiac ATTRv amyloidosis, which can elicit deleterious effects on patient's lung function and aerobic capacity.

An Unusual Case of Chronic Hemoptysis

CASE PRESENTATION

A 62-year-old African American man was admitted to the hospital with hemoptysis. He had a complicated medical history significant for active tobacco use (>50 pack-year history), coronary artery disease, and heart failure with reduced ejection fraction. He reported intermittent episodes of coughing up streaks of blood in the sputum for the past 3 years. For the past few days before this presentation, he had multiple episodes of coughing up over a tablespoon of only blood. He was not on any anticoagulant agents. There were no risk factors for TB, nor was there a history of fevers, chills, shortness of breath, leg swelling, changes in his urine color and frequency or urgency, or unintended weight loss. On admission, he was noted to be breathing comfortably. Vital signs revealed a temperature of 36.6ºC, BP of 138/70 mm Hg, heart rate of 66 beats/min, respiratory of rate of 18 breaths/min, and a blood oxygen saturation level of 98% on room air. Physical examination was significant for decreased bilateral breath sounds with no wheezing, crackles, or rhonchi. Cardiovascular examination revealed normal cardiac rhythm without murmur, rubs, or gallops. There was no clubbing or edema on his extremities.

Likelihood of amyloid formation in COVID-19-induced ARDS

Severe coronavirus disease 2019 (COVID-19) infection leads to multifactorial acute respiratory distress syndrome (ARDS), with little therapeutic success. The pathophysiology associated with ARDS or post-ARDS is not yet well understood. We hypothesize that amyloid formation occurring due to protein homeostasis disruption can be one of the complications associated with COVID-19-induced-ARDS.

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

Quantitative [18F]florbetapir PET/CT may identify lung involvement in patients with systemic AL amyloidosis

PURPOSE

The clinical diagnosis of pulmonary involvement in individuals with systemic AL amyloidosis remains challenging. [18F]florbetapir imaging has previously identified AL amyloid deposits in the heart and extra-cardiac organs. The aim of this study is to determine quantitative [18F]florbetapir pulmonary kinetics to identify pulmonary involvement in individuals with systemic AL amyloidosis.

METHODS

We prospectively enrolled 58 subjects with biopsy-proven AL amyloidosis and 9 control subjects (5 without amyloidosis and 4 with ATTR cardiac amyloidosis). Pulmonary [18F]florbetapir uptake was evaluated visually and quantified as distribution volume of specific binding (Vs) derived from compartmental analysis and simpler semiquantitative metrics of maximum standardized uptake values (SUVmax), retention index (RI), and target-to-blood ratio (TBR).

RESULTS

On visual analysis, pulmonary tracer uptake was absent in most AL subjects (40/58, 69%); 12% (7/58) of AL subjects demonstrated intense bilateral homogeneous tracer uptake. In this group, compared to the control group, Vs (median Vs 30-fold higher, 9.79 vs. 0.26, p < 0.001), TBR (median TBR 12.0 vs. 1.71, p < 0.001), and RI (median RI 0.310 vs. 0.033, p < 0.001) were substantially higher. Notably, the AL group without visually apparent pulmonary [18F]florbetapir uptake also demonstrated a > 3-fold higher Vs compared to the control group (median 0.99 vs. 0.26, p < 0.001). Vs was independently related to left ventricular SUVmax, a marker of cardiac AL deposition, but not to ejection fraction, a marker of cardiac dysfunction. Also, intense [18F]florbetapir lung uptake was not related to [11C]acetate lung uptake, suggesting that intense [18F]florbetapir lung uptake represents AL amyloidosis rather than heart failure.

CONCLUSIONS

[18F]florbetapir PET/CT offers the potential to noninvasively identify pulmonary AL amyloidosis, and its clinical relevance warrants further study.

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.

An Organ System-Based Approach to Differential Diagnosis of Amyloid Type in Surgical Pathology

CONTEXT.—

Amyloidosis is an uncommon but important entity. A protein-based classification of amyloidosis defines the underlying disease process, directing clinical management and providing prognostic information. However, in routine surgical pathology there often is no attempt to classify amyloid other than staining to determine light chain-associated amyloidosis. Systemic and localized amyloidosis vary with respect to frequency of organ involvement by different amyloid types, and most amyloid proteins have commercial antibodies available for identification.

OBJECTIVE.—

To provide a guide for the likelihood of amyloid type by organ system.

DATA SOURCES.—

Literature review based on PubMed searches containing the word amyloid, specifically addressing the prevalence and significance of amyloid proteins in each organ system other than the brain, and the authors' practice experience.

CONCLUSIONS.—

In patients with amyloidosis, determination of the responsible protein is critical for appropriate patient care. In large subspecialty practices and reference laboratories with experience in using and analyzing relevant immunohistochemistry, most amyloid proteins can be identified with an organ-specific algorithm. Referring to an organ-based algorithm may be helpful in providing clinicians with a more specific differential diagnosis regarding amyloid type to help guide clinical evaluation and treatment. When the protein cannot be characterized, mass spectrometry can be performed to definitively classify the amyloid type.