Immune cells and vasa vasorum in the tunica media of atherosclerotic coronary arteries.

In coronary artery disease (CAD), the disruption of the tunica media immune privilege manifests as increased leukocyte infiltration and the formation of vasa vasorum. We aimed to characterize the immune privilege status of the tunica media in human coronary arteries (CAs) with atherosclerotic plaques, by comparing the abundance and composition of immune-cell infiltrates within the individual arterial-wall layers, and by evaluating vasa vasorum neovascularization of the tunica media. The tissue samples were obtained from 36 symptomatic patients with diffuse CAD (aged 60-72 years) who underwent coronary endarterectomy. T and B cells, macrophages and endothelial cells in the CAs were detected by immunohistochemistry. Morphological analysis of CAs showed significant atherosclerotic changes in all specimens. In the media, we observed damage and loss of smooth muscle cells, destruction of the extracellular matrix architecture, and fibrosis. There were 43.3% of immune cells in the intima, 50% in the adventitia, and 6.7% in the media. In the media, 51.1% of the immune cells were T cells (p ˂ 0.001 compared to B cells and macrophages; ANOVA, Scheffe post hoc analysis), 23.5% were B cells, and 25.4% were macrophages. The number of vasa vasorum in the media was 1 in 38.9% of CAs, 2-3 in 36.1%, and ≥4 in 25% of CAs. Our results indicate that, in atherosclerotic CAs, the immune privilege of the media is disrupted by the infiltration of T and B cells, macrophages, and the presence of vasa vasorum.

Deficiency of mast cells in coronary artery endarterectomy of male patients with type 2 diabetes.

BACKGROUND: Type 2 diabetes is an important risk factor for the development of coronary artery disease (CAD). Focal or diffuse inflammation is often present in the vessels of patients with CAD. Mast cells are frequently present in the plaques as well as in the inflammatory infiltrates in the atherosclerotic vessel wall. In the study we wanted to examine whether there are differences in the morphology, number and distribution of mast cells and in their ability to modify the atherosclerotic process in coronary arteries (CA) in the diabetic vs. the hypertensive population of patients with CAD. METHODS: Coronary artery endarterectomy specimens were obtained from patients with diabetes or hypertension as the only risk factor for CAD. The specimens were stained with haematoxylin-eosin and Sulphated Alcian Blue for mast cells and with immunofluorescent methods for fibrinogen-fibrin and IgG deposits in the vessel wall. Both morphological and stereological assessments were conducted for mast cells and mononuclear cell infiltrates. RESULTS: The histological analysis of the vessel wall of diabetic patients in comparison with hypertensive patients showed a damaged endothelial cells layer and deposits of fibrin-fibrinogen and IgG in the tunica intima and media. The stereological count revealed a diminished numerical density of mast cells and a significantly higher volume density of the mononuclear cells. Mast cells displayed cytoplasmic vacuolization, extracellular extrusion of granule and pyknotic nuclei. CONCLUSION: This preliminary study suggests that the impaired mast cells might be the reason for more extensive inflammatory and immunologic atherosclerotic changes in the CA vessel wall of CAD patients with type 2 diabetes.

Histopathologic signs for the inflammatory role of Chlamydia pneumoniae in the high-grade atherosclerotic coronary artery wall.

The aim of the study was to prove the long-lasting and continuously harmful effect of chronic Chlamydia pneumoniae (CPn) infection on vessel walls in patients with diffuse coronary artery disease (CAD). In surgically obtained endarterectomized atherosclerotic plaques grade VI-VIII (Stary classification) from 10 patients with diffuse coronary artery disease and chronic (7) or past (3) CPn infection, signs of inflammatory response of the vessel wall on infectious agents were studied. In all 10 endarterectomized plaque step serial sections, immunologic signs of vessel wall response were present (positive T- and B-lymphocytes, macrophages, and capillarogenesis). In 8 of 10 patients' atherosclerotic plaque, unique features of active vasculitis in the neoarteriolar wall as well as arteriologenesis, were found. Seven of these 8 patients had serologically proven chronic CPn infection, and 1 had past infection. Features of vasculitis as well as arteriologenesis were absent in 2 patients who recovered from CPn infection at the time of surgery. In the endarterectomized segments of 3 randomly chosen patients in this study, the polymerase chain reaction method revealed positive DNA of CPn. Two of these patients had chronic infection, but the third had only a past CPn infection. This study provides evidence that CPn infection has continuous and a long-lasting inflammatory response in the high-grade atherosclerotic coronary artery vessel wall.

Apoptosis and histopathologic changes in diffuse coronary atherosclerosis.

The aims of the study were to investigate the histopathologic characteristics of atherosclerotic lesions and to evaluate the role of apoptosis or programmed cell death in diffuse coronary atherosclerosis. The study included 59 patients who underwent coronary artery bypass grafting coupled with coronary endarterectomy because of diffuse coronary atherosclerosis. Histopathologic analysis of endarterectomy sequesters showed atheroma with confluent extracellular lipid core-type IV lesions in 13 cases (22%); atheroma with lipid core and a cap of fibromuscular layers-type V lesions in 9 cases (15.3%); predominantly calcified fibrous tissue-type VII lesions in 13 cases (22%); and predominantly fibrous tissue-type VIII lesions in 24 cases (40.7%). TUNEL-positive cells were observed in 4 endarterectomy sequesters (6.8%) of subjects with diffuse coronary atherosclerosis. TUNEL-positive cells were demonstrated in the area of mononuclear infiltrates as well as in the vessel wall. The percentage of TUNEL-positive cells in mononuclear infiltrates was 0.5%. Intense mononuclear infiltrates in tunica intima were found in 50% of sequesters, and they consisted of macrophages (40%), T-lymphocytes (17%), and B-lymphocytes (14%). In the area of infiltrates the proportion of MIB-1-positive cells was 2.7%, which was higher than in the intima outside the area of infiltrates (0.5%). In conclusion, apoptosis, which is confined to mononuclear infiltrates, is most likely involved in the development of diffuse coronary atherosclerosis; however, the percentage of apoptotic cells was low (0.5%). A higher proportion of apoptotic cells in the area of infiltrates compared to the rest of the intima was associated with a higher proportion of MIB-1-positive cells. Atherosclerotic lesions in diffuse coronary atherosclerosis were advanced, with a predominance of type VII to VIII lesions.

Apoptosis of myocytes and proliferation markers as prognostic factors in end-stage dilated cardiomyopathy.

INTRODUCTION: The aim of the study was to evaluate the role of apoptosis, proliferation markers, volume density of interstitium, and myofibril volume fraction for the prognosis in patients with end-stage dilated cardiomyopathy (DCM). METHODS: Endomyocardial biopsy was performed during open-heart surgery in 56 patients with end-stage DCM. Patients were divided into two groups, one group with shorter survival (24+/-9 months, mean+/-S.D.) and another group with survival of more than 7 years after operation. The TUNEL method was used for the detection of apoptosis, and immunohistochemical methods were used for the evaluation of inhibitor of apoptosis (bcl-2) and proliferation markers (PCNA and Ki-67). RESULTS: The increased percentage of apoptotic myocytes, decreased expression of bcl-2, and decreased expression of PCNA and Ki-67 antigen was found in the group with early mortality compared to that with longer survival. Myofibril volume fraction was lower and volume density of interstitium was higher in the group with early mortality compared to that with longer survival. CONCLUSION: Apoptosis, bcl-2 expression, and proliferation activity of myocytes, myofibril volume fraction, and volume density of interstitial tissue might be useful in predicting the prognosis (progressive vs. nonprogressive form) of patients with heart failure due to DCM.