Density of Chlamydia pneumoniae is increased in fibrotic and calcified areas of degenerative aortic stenosis.

BACKGROUND: The process of aortic degeneration associated with calcified aortic stenosis shares many similarities with coronary artery atherosclerosis. Inflammation and infection are involved in both diseases. Chlamydia pneumoniae has been identified in atherosclerotic plaques. However, the studies about the presence of C. pneumoniae in degenerative aortic stenotic valves are not conclusive. OBJECTIVE: We investigated whether an association exists between the density of C. pneumoniae and fibrosis or calcification in aortic stenosis. DESIGN: Autopsy and surgical specimens were divided into 3 groups: Normal, 11 normal autopsy valves Atherosclerosis, 10 autopsy valves from patients with systemic atherosclerosis and no aortic stenosis and Aortic stenosis, 14 surgical specimens of aortic valves replaced due to aortic stenosis. SETTING: Heart Institute (InCor), University of São Paulo Medical School. PATIENTS: Aortic valves from patients aged 52+/-16 years, 69+/-9 years, and 71+/-8 years. INTERVENTION: Specimens were evaluated by immunohistochemical technique (to detect C. pneumoniae antigens), in situ hybridization, and electron microscopy (to quantify the density of C. pneumoniae in the valves). MEASUREMENTS: The aortic stenosis group was analyzed according to 3 subregions: aortic stenosis-preserved, peripheral preserved regions; aortic stenosis-fibrosis, peri-calcified fibrotic tissue; and aortic stenosis-calcification, calcified nodules. RESULTS: The median values of C. pneumoniae antigens were 0.09, 0.30, 0.18, 1.33, and 3.3 in groups Normal, Atherosclerosis, Aortic stenosis-preserved, Aortic stenosis-fibrosis, and Aortic stenosis-calcification, respectively. The amount of C. pneumoniae was greater in the Atherosclerosis and Aortic stenosis-calcification groups than in the Normal group (P<0.05). C. pneumoniae was greater in the Aortic stenosis group in the calcified and fibrotic regions than in preserved region (P<0.05). CONCLUSION: An association was found between the higher density of C. pneumoniae and fibrosis/calcification in stenotic aortic valves.

[Chlamydia pneumoniae and Mycoplasma pneumoniae in calcified nodes of stenosed aortic valves]. / Chlamydia pneumoniae e Mycoplasma pneumoniae nos nódulos de calcificação da estenose da valva aórtica.

OBJECTIVE: We investigated whether Chlamydia pneumoniae (CP) and Mycoplasma pneumoniae (MP) are present in aortic valve stenosis (AS). METHODS: Immunohistochemistry was utilized to identify CP antigens, in situ hybridization to identify MP DNA, and electron microscopy was used to evaluate the following three groups: Normal - 11 normal autopsy valves; Atherosclerosis - 10 autopsy valves from patients with systemic atherosclerosis and no AS; and AS - 14 surgical specimens of AS analyzed in 3 sub-regions: AS-Preserved - peripheral, preserved regions; AS-Fibrosis - peri-calcified fibrotic tissue; and AS-Calcification - calcified nodules. RESULTS: The positive area fraction of CP antigen median values were 0.09, 0.30, 0.18, 1.33, and 3.3 in groups Normal, Atherosclerosis, AS-Preserved, AS-Fibrosis, and AS-Calcification, respectively. CP density was significantly greater in Atherosclerosis and AS-Calcification than in Normal (P<0.05). Within the AS group, the amount of CP was greater in the Calcification and Fibrosis regions (P<0.05). MP-DNA positive area fraction (median values) were 0.12, 0.44, 0.07, 0.36, and 1.52 in groups Normal, Atherosclerosis, AS-Preserved, AS-Fibrosis, and AS-Calcification, respectively. The amount of MP-DNA was greater in AS-Calcification than in Normal (P<0.05). Within the AS group, MP-DNA was in larger quantity in the Calcification and Fibrosis regions (P<0.05). CONCLUSION: AS Calcified nodes present higher concentration of CP and MP suggesting that these bacteria may be associated with the development of calcification and inflammation. This adds novel similarities between AS and the atherosclerosis process, which may have infection mechanisms involved.

Chlamydia pneumoniae e Mycoplasma pneumoniae nos nódulos de calcificacão da estenose da valva aórtica / Chlamydia pneumoniae and Mycoplasma pneumoniae in calcified nodes of stenosed aortic valves

OBJETIVO: Investigar se chlamydia pneumoniae (CP) ou mycoplasma pneumoniae (MP) estão presentes na estenose da valva aórtica (EA). MÉTODOS: Imuno-histoquímica foi utilizada para identificar os antígenos de CP (Ag-CP), a hibridizacão in situ para identificar o DNA de MP, e microscopia eletrônica para avaliacão dos dois agentes, nos grupos: normal - 11 valvas normais de autópsia; aterosclerose - 10 valvas de pacientes com aterosclerose sistêmica de autópsia e sem EA; e EA - 14 espécimes cirúrgicos provenientes de pacientes com EA analisados em 3 sub-regiões: EA-preservada - regiões mais preservadas na periferia da valva; EA-fibrose - tecido fibrótico peri-calcificacão; e EA-calcificacão - nódulos calcificados. RESULTADOS: As medianas da fracão de área positiva para Ag-CP foram 0,09; 0,30; 0,18; 1,33; e 3,3 nos grupos acima descritos, respectivamente. A densidade de CP foi significativamente maior nos grupos aterosclerose e EA-calcificacão em relacão ao normal (p<0,05). Dentro do grupo EA, a quantidade de CP foi maior nas regiões de fibrose e calcificacão (p<0,05). As fracões de área positivas para MP-DNA (medianas) foram 0,12; 0,44; 0,07; 0,36; e 1,52 nos grupos acima descritos, respectivamente. A quantidade de MP-DNA foi maior na EA-calcificacão em relacão ao normal (p<0,05). Dentro do grupo EA, maior quantidade de MP-DNA foi encontrada nas regiões de calcificacão e fibrose (p<0,05). CONCLUSAO: Os nódulos de calcificacão da EA tinham maior concentracão de CP e MP sugerindo que essas bactérias possam estar associadas ao desenvolvimento de calcificacão e inflamacão, apontando novas semelhancas entre os processos de EA e aterosclerose, que podem ter mecanismos infecciosos envolvidos.

Acute Chagas' disease: immunohistochemical characteristics of T cell infiltrate and its relationship with T. cruzi parasitic antigens.

OBJECTIVE: The present work analysed endomyocardial biopsies of patients with acute Chagas' disease in order to evaluate the frequency and intensity of T. cruzi antigens, CD4+ and CD8+ T cells to determine the characteristics of this recurrent disease in Venezuela. MATERIAL AND METHODS: Twelve endomyocardial biopsies of patients with Chagas' disease, 12 to 51 years old, (7M and 5F) were analysed. T. cruzi antigens and CD4+ (helper) and CD8+ (cytotoxic-suppressor) T cells were detected by the immunoperoxidase technique. The presence and intensity of lymphocytic myocarditis was evaluated according to the degree of myocardial fibre injury caused by inflammatory infiltrate. RESULTS: Myocarditis was present in 100% of the cases. The mean numbers of CD4+ T cell and CD8+ T cell were 11.00 (+/- 10.29); 14.69 (+/- 13.08) and the CD4/CD8 T cell ratio was 0.75. T. cruzi antigens were detected in 58%. There was a good correlation between the numbers of CD4 and CD8 T cells of each case and a lack of correlation with the amount of T. cruzi antigens. CONCLUSION: All patients with acute Chagas' disease show some degree of myocarditis that seems to be directly related to the presence of parasitic antigens. Both CD4 and CD8 T cells participate in this process. We are following these patients to see if patients with severe myocarditis and more parasite antigens in the acute phase will develop chronic heart failure.

Mycoplasma pneumoniae and Chlamydia pneumoniae in calcified nodules of aortic stenotic valves.

Aortic Valve Stenosis (AVS) has been explained as an atherosclerotic process of the valve as they often exhibit inflammatory changes with infiltration of macrophages, T lymphocytes and lipid infiltration. The present study investigated whether the bacteria Chlamydia pneumoniae (CP) and Mycoplasma pneumoniae (MP), detected previously in atherosclerotic plaques, are also present in AVS. Ten valves surgically removed from patients with AVS were analyzed by immunohistochemistry, in situ hybridization, and electron microscopy. The mean and standard deviation of the percentage areas occupied by CP antigens and MP - DNA were respectively 6.21 +/- 5.41 and 2.27 +/- 2.06 in calcified foci; 2.8 +/- 3.33 and 1.78+/- 3.63 in surrounding fibrotic areas, and 0.21 +/- 0.17 and 0.12 +/- 0.13 in less injured parts of the valve. There was higher amount of CP and MP in the calcified foci and in the surrounded fibrosis than in more preserved valvular regions. In conclusion, the fact that there were greater amounts of CP and MP in calcification foci of AVS favors the hypothesis that AS is not an inevitable degenerative process due to aging, but rather that it may be a response to the presence of these bacteria, similarly to the morphology detected in atherosclerosis damage.

Mycoplasma pneumoniae and Chlamydia pneumoniae in calcified nodules of aortic stenotic valves

Aortic Valve Stenosis (AVS) has been explained as an atherosclerotic process of the valve as they often exhibit inflammatory changes with infiltration of macrophages, T lymphocytes and lipid infiltration. The present study investigated whether the bacteria Chlamydia pneumoniae (CP) and Mycoplasma pneumoniae (MP), detected previously in atherosclerotic plaques, are also present in AVS. Ten valves surgically removed from patients with AVS were analyzed by immunohistochemistry, in situ hybridization, and electron microscopy. The mean and standard deviation of the percentage areas occupied by CP antigens and MP - DNA were respectively 6.21 +/- 5.41 and 2.27 +/- 2.06 in calcified foci; 2.8 +/- 3.33 and 1.78+/- 3.63 in surrounding fibrotic areas, and 0.21 +/- 0.17 and 0.12 +/- 0.13 in less injured parts of the valve. There was higher amount of CP and MP in the calcified foci and in the surrounded fibrosis than in more preserved valvular regions. In conclusion, the fact that there were greater amounts of CP and MP in calcification foci of AVS favors the hypothesis that AS is not an inevitable degenerative process due to aging, but rather that it may be a response to the presence of these bacteria, similarly to the morphology detected in atherosclerosis damage

Great amount of C.pneumoniae in rupture plaque vessel segments at autopsy: a comparative study with stable plaques

A possible relationship between C.pneumoniae (CP) infection, atherosclerosis and acute myocardial infarction is a debated matter. Now we performed the search of CP in histological segments of fatal ruptured plaques and of stable plaques by histochemistry (Macchiavello stain), immunohistochemistry and in situ hybridization techniques. Electron microscopy and confocal laser microscopy techniques were used in two additional cases. The semi-quantitification of CP + cells (0-4+) and quantification of lymphocytes demonstrated greater amount of CP + cells and more inflammation in the adventitia of vulnerable plaque vessel segments than of stable ones, larger amount of CP + cells in adventitia than in the plaque and high frequency of CP + cells in all groups studied. This preliminary study strongly suggests a direct pathogenetic involvement of adventitial CP in the rupture of the atheromatous plaque, development of acute myocardial infarction and also in the development of atherosclerosis.