Deposition of amyloid proteins in the epicardial coronary arteries of 58 patients with primary systemic amyloidosis.
ABSTRACT We sought to determine the distribution and the effect of amyloid on epicardial coronary arteries in patients with primary cardiac amyloidosis.
We reviewed pathologic specimens taken after autopsy or cardiac transplantation from 58 patients with primary cardiac amyloidosis. Patients were seen from 1981 to 2000. Multiple sections of epicardial coronary arteries (left anterior descending artery, left circumflex artery, and right coronary artery) were examined to determine the degree of amyloid deposition in the intima, media, adventitia, and vasa vasorum (vasa vasorum are nutrient arteries for the coronary arteries themselves).
In 56 of 58 patients (97%), amyloid was present in epicardial coronary arteries. Amyloid was identified in all artery layers (intima, media, and adventitia), and more patients had amyloid in the adventitia. However, amyloid did not cause intraluminal obstruction of epicardial coronary arteries in any patient. The vasa vasorum had considerable deposits and, in many patients, were obstructed by amyloid. Patients with obstruction of the vasa vasorum were significantly more likely to have obstructive intramural coronary amyloidosis than patients without vasa vasorum obstruction (P=.002).
The epicardial coronary arteries of patients with primary cardiac amyloidosis had extensive amyloid deposition. This deposition, however, did not lead to obstruction of epicardial coronary arteries and therefore did not contribute to ischemic syndromes observed in these patients. Obstruction of the vasa vasorum was associated with obstructive intramural coronary amyloidosis.
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ABSTRACT: BACKGROUND: Amyloidosis is a life-threatening protein misfolding disease and affects cardiac tissue, leading to heart failure, myocardial ischemia and arrhythmia. Amyloid deposits result in oxidative stress, inflammation and apoptosis. The purpose of this study was to examine the role of innate defense components, i.e., Deleted in Malignant Brain Tumors 1 (DMBT1) and the complement system, in different types of cardiac amyloidosis. METHODS: Expression of DMBT1 and of the complement proteins C1q, C3d and C4d in cardiac specimens of patients with different types of amyloidosis were determined by immunohistochemistry and correlated with amyloid deposits stained by Congo red dye. RESULTS: Strong DMBT1 staining adjacent to amyloid deposits was detected in different amyloidosis types, depending on the extent of the deposits. DMBT1 is localized in the endomysium and perimysium, in the endocardium, in the myocytes and in endothelial cells of affected transmural vessels. C1q, C3d and C4d were detected in the amyloid deposits but also in the endomysium and perimysium, in some myocytes, in endothelial cells, in the endocardium, and around the amyloid deposits. CONCLUSIONS: Up-regulated DMBT1 and complement activation in cardiac amyloidosis may be part of the activated pathways induced by protein aggregation and the consecutive inflammatory reaction.Cardiovascular pathology: the official journal of the Society for Cardiovascular Pathology 12/2012; · 1.63 Impact Factor
Article: Systemic Amyloidoses.[Show abstract] [Hide abstract]
ABSTRACT: The amyloidoses are a group of protein misfolding diseases in which the precursor protein undergoes a conformational change that triggers the formation of amyloid fibrils in different tissues and organs, causing cell death and organ failure. Amyloidoses can be either localized or systemic. In localized amyloidosis, amyloid deposits form at the site of precursor protein synthesis, whereas in systemic amyloidosis, amyloid deposition occurs distant from the site of precursor protein secretion. We review the type of proteins and cells involved and what is known about the complex pathophysiology of these diseases. We focus on light chain amyloidosis to illustrate how biochemical and biophysical studies have led to a deeper understanding of the pathogenesis of this devastating disease. We also review current cellular, tissue, and animal models and discuss the challenges and opportunities for future studies of the systemic amyloidoses. Expected final online publication date for the Annual Review of Biochemistry Volume 82 is June 02, 2013. Please see http://www.annualreviews.org/catalog/pubdates.aspx for revised estimates.Annual review of biochemistry 02/2013; · 29.88 Impact Factor
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ABSTRACT: Light chain amyloidosis is one of the unique examples within amyloid diseases where the amyloidogenic precursor is a protein that escapes the quality control machinery and is secreted from the cells to be circulated in the bloodstream. The immunoglobulin light chains are produced by an abnormally proliferative monoclonal population of plasma cells that under normal conditions produce immunoglobulin molecules such as IgG, IgM or IgA. Once the light chains are in circulation, the proteins misfold and deposit as amyloid fibrils in numerous tissues and organs, causing organ failure and death. While there is a correlation between the thermodynamic stability of the protein and the kinetics of amyloid formation, we have recently found that this correlation applies within a thermodynamic range, and it is only a helpful correlation when comparing mutants from the same protein. Light chain amyloidosis poses unique challenges because each patient has a unique protein sequence as a result of the selection of a germline gene and the incorporation of somatic mutations. The exact location of the misfolding process is unknown as well as the full characterization of all of the toxic species populated during the amyloid formation process in light chain amyloidosis.Current topics in medicinal chemistry 01/2013; · 4.47 Impact Factor