Pulmonary hypertension and amyloidosis--an uncommon association: a case report and review of the literature

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.

The spectrum of pulmonary amyloidosis

Amyloidosis is a disease caused by misfolded proteins that deposit in the extracellular matrix as fibrils, resulting in the dysfunction of the involved organ. The lung is a common target of Amyloidosis, but pulmonary amyloidosis is uncommonly diagnosed since it is rarely symptomatic. Diagnosis of pulmonary amyloidosis is usually made in the setting of systemic amyloidosis, however in cases of localized pulmonary disease, surgical or transbronchial tissue biopsy might be indicated. Pulmonary amyloidosis can be present in a variety of discrete entities. Diffuse Alveolar septal amyloidosis is the most common type and is usually associated with systemic AL amyloidosis. Depending on the degree of the interstitial involvement, it may affect alveolar gas exchange and cause respiratory symptoms. Localized pulmonary Amyloidosis can present as Nodular, Cystic or Tracheobronchial Amyloidosis which may cause symptoms of airway obstruction and large airway stenosis. Pleural effusions, mediastinal lymphadenopathy and pulmonary hypertension has also been reported. Treatment of all types of pulmonary amyloidosis depends on the type of precursor protein, organ involvement and distribution of the disease. Most of the cases are asymptomatic and require only close monitoring. Diffuse alveolar septal amyloidosis treatment follows the treatment of underlying systemic amyloidosis. Tracheobronchial amyloidosis is usually treated with bronchoscopic interventions including debulking and stenting or with external beam radiation. Long-term prognosis of pulmonary amyloidosis usually depends on the type of lung involvement and other organ function.

Ultrasound-controlled transthoracic true-cut needle biopsy in pulmonary nodular amyloidosis

The current case report presents a 59-year-old man with imaging studies of the thorax showing nodular lesions in the lungs bilaterally. Based on radiographic and CT images, preliminary diagnoses for possible granulomatosis (tuberculosis) or pulmonary metastatic dissemination of a neoplastic process were made. An ultrasound-controlled transthoracic true-cut needle biopsy of a subpleural lesion was performed. Special staining with Congo red and examination with a polarizing light microscope for detection of amyloid confirmed the diagnosis of 'pulmonary nodular amyloidosis' by visualizing green birefringence.

Cardiac amyloidosis presenting as pulmonary arterial hypertension: A case report

BACKGROUND

Pulmonary hypertension is a rare cardiopulmonary disease, with an insidious onset that usually worsens rapidly. Amyloid light chain (AL) amyloidosis is a rare systemic disease caused by extracellular deposition of pathologic, insoluble, and proteinaceous fibrils in organs and tissues; however, it is difficult to diagnose given its varied and nonspecific symptoms. To date, rare cases of amyloidosis with pulmonary hypertension have been reported. Of note, the optimal treatments for cardiac amyloidosis complicated with pulmonary hypertension remain unclear.

CASE SUMMARY

We report a case of a 51-year-old woman who presented with progressively worsening dyspnea. Transthoracic echocardiography indicated severe pulmonary hypertension. Twenty-seven months after first admission, the patient returned with symptoms of progressive heart failure. A myocardial tissue sample stained with Congo red was positive, and the patient was ultimately diagnosed with AL amyloidosis with cardiac involvement.

CONCLUSION

Although pulmonary hypertension may be idiopathic, it is frequently associated with other conditions. In rare cases, pulmonary hypertension can be a complication of AL amyloidosis, which should be seriously considered in any adult presenting with nonspecific signs or symptoms of cardiac distress.

Cardiac Amyloidosis Presenting as Isolated Severe Pulmonary Artery Hypertension

A 58-year-old woman presented with dyspnea on exertion and bilateral pedal edema for 3 months. She was found to have severe pulmonary hypertension (PH) with the right ventricular failure. The detailed evaluation did not reveal any secondary cause for PH (cardiac disease, pulmonary embolism, interstitial or other lung disease, collagen vascular disease, portal hypertension, or chronic liver disease). Meanwhile, her workup revealed multiple myeloma. Abdominal fat pad biopsy was performed because PH as an isolated manifestation of cardiac amyloidosis was previously reported. Thus, she was diagnosed to have systemic amyloidosis secondary to myeloma. PH was attributed to cardiac amyloidosis. We present a patient with PH and amyloidosis secondary to multiple myeloma. PH and primary systemic amyloidosis without cardiac or parenchymal lung involvement are extremely rare with only a few cases reported in the past.

[A rare cause of pulmonary arterial hypertension: Thoracic amyloidosis]

Isolated thoracic involvement in amyloidosis is a rare and serious condition. Its association with pulmonary arterial hypertension (PAH) usually weakens the prognosis. We report the case of a 40-year-old man with a smoking history, hospitalized for chest pain, abdominal pain and acute respiratory distress. The cardiac ultrasound revealed a circumferential pericardial effusion as well as a pulmonary artery systolic pressure (PAPS) at 80mmHg. Chest imaging (computed tomography scan and magnetic resonance imaging) showed a tissue process developed in the pericardial sheath (60×45mm) sheathing the ascending aorta and infiltrating the trunk of the pulmonary artery and its right branch. Anatomopathological and immunohistochemical study of the process revealed AL amyloidosis. Note that the patient had no signs of extrathoracic amyloidosis. Blood and urine electrophoresis and immunoelectrophoresis as well as bone marrow mylogram and biopsy were normal. The patient was put on oral anticoagulant as he presented with PAH. A therapeutic protocol with thalidomide and dexamethasone has been initiated. The course of the disease was marked by total regression of the clinical signs, a marked decrease in the amyloid process on imaging and a normalization of the PAPS; our follow-up being three years.

Pulmonary Vascular Disease Due to Plasma Cell Dyscrasia

Pulmonary hypertension (PH) has been described in myeloproliferative disorders; monoclonal plasma cell disorder such as polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes syndrome; and plasma cell dyscrasias such as multiple myeloma and amyloidosis. We describe 4 cases of PH likely due to pulmonary vascular involvement and myocardial deposition from light chain deposition disease, amyloidosis, and multiple myeloma. On the basis of our clinical experience and literature review, we propose screening for plasma cell dyscrasia in patients with heart failure with preserved ejection fraction, unexplained PH, and hematological abnormalities. We also recommend inclusion of cardiopulmonary screening in patients with monoclonal gammopathy of undetermined significance.

A preliminary study of the effect of a high-salt diet on transcriptome dynamics in rat hypothalamic forebrain and brainstem cardiovascular control centers

BACKGROUND

High dietary salt intake is strongly correlated with cardiovascular (CV) diseases and it is regarded as a major risk factor associated with the pathogenesis of hypertension. The CV control centres in the brainstem (the nucleus tractus solitarii (NTS) and the rostral ventrolateral medulla (RVLM)) and hypothalamic forebrain (the subfornical organ, SFO; the supraoptic nucleus, SON and the paraventricular nucleus, PVN) have critical roles in regulating CV autonomic motor outflows, and thus maintaining blood pressure (BP). Growing evidence has implicated autonomic regulatory networks in salt-sensitive HPN (SSH), but the genetic basis remains to be delineated. We hypothesized that the development and/ or maintenance of SSH is reliant on the change in the expression of genes in brain regions controlling the CV system.

METHODOLOGY

We used RNA-Sequencing (RNA-Seq) to describe the differential expression of genes in SFO, SON, PVN, NTS and RVLM of rats being chronically fed with high-salt (HS) diet. Subsequently, a selection of putatively regulated genes was validated with quantitative reverse transcription polymerase chain reaction (qRT-PCR) in both Spontaneously Hypertensive rats (SHRs) and Wistar Kyoto (WKY) rats.

RESULTS

The findings enabled us to identify number of differentially expressed genes in SFO, SON, PVN, NTS and RVLM; that are either up-regulated in both strains of rats (SON- Caprin2, Sctr), down-regulated in both strains of rats (PVN- Orc, Gkap1), up-regulated only in SHRs (SFO- Apopt1, Lin52, AVP, OXT; SON- AVP, OXT; PVN- Caprin2, Sclt; RVLM- A4galt, Slc29a4, Cmc1) or down-regulated only in SHRs (SON- Ndufaf2, Kcnv1; PVN- Pi4k2a; NTS- Snrpd2l, Ankrd29, St6galnac6, Rnf157, Iglon5, Csrnp3, Rprd1a; RVLM- Ttr, Faim).

CONCLUSIONS

These findings demonstrated the adverse effects of HS diet on BP, which may be mediated via modulating the signaling systems in CV centers in the hypothalamic forebrain and brainstem.

The lung in amyloidosis

Amyloidosis is a disorder caused by misfolding of autologous protein and its extracellular deposition as fibrils, resulting in vital organ dysfunction and eventually death. Pulmonary amyloidosis may be localised or part of systemic amyloidosis.

Pulmonary interstitial amyloidosis is symptomatic only if the amyloid deposits severely affect gas exchange alveolar structure, thus resulting in serious respiratory impairment. Localised parenchymal involvement may be present as nodular amyloidosis or as amyloid deposits associated with localised lymphomas. Finally, tracheobronchial amyloidosis, which is usually not associated with evident clonal proliferation, may result in airway stenosis.

Because the treatment options for amyloidosis are dependent on the fibril protein type, the workup of all new cases should include accurate determination of the amyloid protein. Most cases are asymptomatic and need only a careful follow-up. Diffuse alveolar-septal amyloidosis is treated according to the underlying systemic amyloidosis. Nodular pulmonary amyloidosis is usually localised, conservative excision is usually curative and the long-term prognosis is excellent. Tracheobronchial amyloidosis is usually treated with bronchoscopic interventions or external beam radiation therapy.

Pulmonary arterial hypertension in primary amyloidosis

Amyloidosis involves extravascular deposition of fibrillar proteins within tissues and organs. Primary light chain amyloidosis represents the most common form of systemic amyloidosis involving deposition of monoclonal immunoglobulin light chains. Although pulmonary amyloid deposition is common in primary amyloidosis, clinically significant pulmonary amyloidosis is uncommon, and elevated pulmonary artery pressures are rarely observed in the absence of other underlying etiologies for pulmonary hypertension, such as elevated filling pressures secondary to cardiac amyloid. In this case report, we present a patient with primary light chain amyloidosis and pulmonary arterial hypertension in the setting of pulmonary vascular and right ventricular myocardial amyloid deposition.

Gelsolin amyloid angiopathy causes severe disruption of the arterial wall

Hereditary gelsolin amyloidosis (HGA) is a dominantly inherited systemic disease reported worldwide. HGA is characterized by ophthalmological, neurological, and dermatological manifestations. AGel amyloid accumulates at basal lamina of epithelial and muscle cells, thus amyloid angiopathy is encountered in nearly every organ. HGA patients have cardiovascular, hemorrhagic, and potentially vascularly induced neurological problems. To clarify pathomechanisms of AGel angiopathy, we performed histological, immunohistochemical, and electron microscopic analyses on facial temporal artery branches from 8 HGA patients and 13 control subjects. We demonstrate major pathological changes in arteries: disruption of the tunica media, disorganization of vascular smooth muscle cells, and accumulation of AGel fibrils in arterial walls, where they associate with the lamina elastica interna, which becomes fragmented and diminished. We also provide evidence of abnormal accumulation and localization of collagen types I and III and an increase of collagen type I degradation product in the tunica media. Vascular smooth muscle cells appear to be morphologically and semi-quantitatively normal, only their basal lamina is often thickened. In conclusion, angiopathy in HGA results in severe disruption of arterial walls, characterized by prominent AGel deposition, collagen derangement and severe elastolysis, and it may be responsible for several, particularly hemorrhagic, disease manifestations in HGA.

Pulmonary arterial hypertension due to pulmonary vascular amyloid deposition in a patient with multiple myeloma

Systemic amyloidosis is characterized by amyloid deposition throughout the body and subsequent dysfunction of various organs. Although pulmonary amyloidosis does occur, pulmonary hypertension (PH) caused by amyloidosis is extremely rare. In most of these cases, amyloid deposition occurred diffusely in alveolar septa, indicating that PH was due to lung disease and/or hypoxia. On the other hand, the mechanism of PH due to amyloid deposition in the pulmonary arteries has never been demonstrated. Here, we report the first case of PH due to amyloid deposition in pulmonary elastic arteries and muscular artery, which was complicated by multiple myeloma (MM). In the autopsy specimen of the patient, amyloid deposition was found mainly in the pulmonary arterial media, along with intimal thickening with luminal narrowing. PH thus appeared to be caused by marked decrease of pulmonary elasticity due to the amyloid deposition in the arterial media that resulted in stasis of the blood flow and subsequent luminal narrowing. Our present data demonstrates a new concept of PH caused by amyloidosis, namely, pulmonary arterial hypertension due to amyloidosis.

A 70-Year-Old Man With Large Cervical and Mediastinal Lymphadenopathies

We present a case of a 70-year-old man with enlarged mediastinal and cervical lymph nodes that provided interesting radiologic and pathologic observations. The 70-year-old black man was found to have enlarged mediastinal lymph nodes. He had symptoms of atypical chest pain and generalized weakness for 2 weeks prior to the diagnosis. He denied shortness of breath, fever, chills, or night sweats. He was treated for hypertension and onychomycosis. Basic laboratory findings were within normal limits. Pulmonary function tests at the time of presentation showed FEV1, FVC, and FEV1/FVC ratio of 123% predicted, 133% predicted, and 0.7, respectively. Meanwhile, total lung capacity and carbon monoxide diffusing capacity were 103% and 107% predicted, respectively. Two weeks before he presented to our institution, the patient underwent bronchoscopy with transbronchial biopsies of the right lower lobe and endobronchial ultrasound-guided transbronchial needle aspiration of the right hilar lymph nodes.

Pulmonary hypertension complicating multiple myeloma

Pulmonary hypertension (PH) is an infrequently reported complication of multiple myeloma (MM). PH has been more commonly associated with amyloidosis, myeloproliferative diseases, and the POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, skin changes) syndrome. PH in MM is typically mild to moderate and may be secondary to a variety of conditions, which include left ventricular dysfunction, high-output cardiac failure, chronic kidney disease, treatment-related toxicities, and precapillary involvement. We describe 3 patients with MM and severe PH. Each patient underwent right heart catheterization. All patients demonstrated elevated pulmonary pressures, transpulmonary gradients, and pulmonary vascular resistance. Each patient was ultimately treated with pulmonary vasodilator therapy with improvement in cardiopulmonary symptoms. Additional studies are needed to define the prevalence, prognosis, and pathogenesis of PH in this complex population and to help clarify who may benefit from targeted PH therapy.

Respiratory Tract Amyloidosis. State-of-the-Art Review with a Focus on Pulmonary Involvement

Amyloidosis is a constellation of disease entities characterized by abnormal extracellular deposition and accumulation of protein and protein derivatives, which show apple-green birefringence when stained with Congo red and viewed under polarized light. Amyloid can infiltrate virtually all organ systems and can display multiple and diverse imaging findings. Pathologically, respiratory involvement occurs in 50 % of patients with amyloidosis, and its clinical signs and symptoms vary depending on whether the disease is systemic or localized. The four main patterns of respiratory tract involvement are tracheobronchial, nodular parenchymal, diffuse alveolar septal, and lymphatic. Imaging findings of amyloidosis are nonspecific and vary in each pattern; knowledge about the disease impairment type is thus very important, and amyloidosis should be considered in the differential diagnosis of other very common diseases, such as infectious diseases, neoplasms, and vasculitis. This literature review describes the main clinical and imaging manifestations of amyloidosis, focusing on respiratory tract involvement and differential diagnosis.

Autoimmune disease leading to pulmonary AL amyloidosis and pulmonary hypertension

A 33-year-old woman with past history of Sjögren's syndrome and systemic lupus erythematosus presented with dyspnea and syncope secondary to pulmonary hypertension. After progressive symptoms over 4 years, she received bilateral lung transplantation. Histopathology of the explanted lungs showed isolated pulmonary amyloid light-chain amyloidosis and pulmonary cysts. No evidence of systemic amyloidosis was found at the time of transplantation. Seven years post lung transplantation, she remains well with no evidence of systemic amyloidosis recurrence.

Pulmonary hypertension in interstitial lung disease

Pulmonary hypertension (PH) may complicate the course of many forms of advanced interstitial lung disease (ILD) and has been shown to portend a worse outcome. The aetiology of PH is likely multifactorial with variable contribution of factors amongst the different diseases. The most common such conditions include idiopathic pulmonary fibrosis, sarcoidosis, connective tissue disease-related ILD and pulmonary langerhans cell histiocytosis. Whether the course and impact of PH in these conditions can be modified by therapy requires further study.