Myocardial inflammatory infiltrate in human chronic chagasic cardiomyopathy: Immunohistochemical findings.

Chagas' disease is the most common form of chronic myocarditis in the world. It is characterized by a progressive chronic myocarditis that leads to cardiomegaly, arrhythmias, cardiac failure, and thromboembolic phenomena. This communication reports studies on the immunohistochemistry of chronic infiltrates in 30 endomyocardial biopsies and in contracting and specialized myocardium of autopsies of four patients suffering from Chagas' cardiomyopathy. Expression of the following antigens was studied: common leucocyte antigen (CLA-CD45R), L-26(CD20), CD68, kappa and lambda light chains and T-UCLH-1 (CD45RO), and MB-1. Streptavidin-peroxidase and streptavidin-alkaline phosphatase with biotinylated anti-mouse IgG were used as detection systems. Double immunostaining for the simultaneous demonstration of T lymphocytes (CD45R0) and macrophages was performed using both immunoenzymatic techniques consecutively. Expression of CD31 was detected for the demonstration of endothelial cells. In endomyocardial biopsies, tissue forms of trypanosomes were not found. The percentage of fibrous tissue was 24.1% ± 12.8% (range 8.2%-49%). Eosinophils were scarce (1/high-power field), but associated with necrotic areas of the myocardium. Mast cells were scarce or absent. They were always situated in fibrotic areas. The most remarkable finding was the presence of infiltrates consisting of macrophages and CLA-positive mononuclear cells. Twenty-six and one-half percent of them were T lymphocytes, and 10.5% were B lymphocytes. Lymphocytic infiltration was particularly associated with necrotic and degenerative myocardial lesions. Thirty percent of the infiltrate was composed of macrophages (positive CD68 cells). The remaining infiltrate was composed of mononuclear cells resembling macrophages and CLA-negative mononuclear cells. Contacts between CD68-positive cells and T lymphocytes were frequently found. CD31 antibodies clearly pointed out normal endothelial cells, in either normal or damaged vessels. No isolated cells positive for these antibodies were found within the mononuclear infiltrate. In autopsied hearts, myocardial lesions consisted of a chronic inflammatory process with fibrotic scars and extensive mononuclear infiltrates. No amastigote nests were found. A statistically significant difference (p < 0.05) was obtained when the percentage of fibrosis was compared in the specialized and contracting myocardiums (51.6% ± 18% vs. 43.4 % ± 8%). Eosinophils were scarce in infiltrates, reaching 5%, and they were associated with necrotic myocardium. Mast cells also were scarce or absent in specialized and in contracting myocardium. Almost all the lymphocytic population was T lymphocytes. Such infiltrates were more prominent in the working myocardium (39%) and in the specialized cells of the left branch of the His bundle than in the atrioventricular node and in the right Hisian branch (34.4%). The 31% of mononuclear cells were CD68 positive, thus corresponding to macrophages. Contacts among T lymphocytes and macrophages were frequently observed. Although much that is concerned with Chagas' cardiomyopathy is controversial, these may be the major ingredients for its pathogenesis: the parasite or a part of it, lymphocytes and macrophages, and fibrosis. Then a multifactorial or "combined theory" may be suggested to explain the sequence of events that lead to the chronic stage of the disease.

Histopathology of the heart conducting system in experimental Chagas disease in mice.

Although mice infected with Trypanosoma cruzi develop a wide variety of electrocardiographic (ECG) alterations, the typical isolated right bundle branch block or its association with the left anterior hemiblock patterns are not found in this model. This has been explained as related to topographic differences in the anatomy of the murine conducting system. However, there is no conclusive evidence that the murine conducting system differs from the human system. In this study, the anatomy of the murine conducting system is described, as well as its involvement in the chronic stages of experimental infection. 24 three-month-old C3H mice were infected with 50 bloodstream forms of T. cruzi, Tulahuén strain. Animals were killed after 3, 8 and 12 months. Whole frontal sections of the heart, including the conducting system, were serially studied. The sinoatrial node was located in the right atrial appendage, or in the junction between the superior vena cava and the right atrium, or "riding" on the interatrial septum. The atrioventricular (A-V) node and the His bundle showed a similar anatomic course to that in man. Therefore, there was no important anatomical difference that might have explained the lack of the ECG patterns observed in human chagasic myocardiopathy. The inflammatory involvement and the lesions of the conducting system were diverse and rarely severe. No significant difference was observed in animals killed at different times. The lesions in the working myocardium were similar to those observed in humans (chronic inflammatory infiltrates). Nevertheless, the topography of lesions was different: there was a selective involvement in the neighbourhood of the A-V groove.(ABSTRACT TRUNCATED AT 250 WORDS)

Structural changes in implanted cardiac valvular bioprostheses constructed of glycerol-treated human dura mater.

Histological, scanning and transmission electron microscope studies were made of normal human dura mater and cardiac valvular bioprostheses made of glycerol-treated human dura mater recovered after having been implanted in the aortic position (8 patients) or the mitral position (1 patient) for periods up to 4 years. Human dura mater has two layers: an inner or meningeal layer and an outer or endosteal layer. The surface of the inner layer is smoother than that of the outer layer. Both layers are composed mainly of large, wavy collagen fibrils (which are thought to correspond to type I collagen) and are relatively poor in elastic fibers and proteoglycans. Small calcific deposits were found in normal dura from older patients. Changes occurring in dura mater bioprostheses within 2 days after implantation consisted mainly of small surface thrombi. Calcific nodules, degenerated collagen and evidence of penetration of erythrocytes and plasma proteins into the cusps were observed in bioprostheses that had failed after being in place for 1-4 years. The calcific deposits and the degenerated collagen appeared structurally similar to those in glutaraldehyde-treated porcine aortic valvular bioprostheses. However, collagen fibrils in the latter were smaller than those in dura mater. Platelet aggregates on the cuspal surfaces were much less numerous in dura mater bioprostheses than in porcine aortic valvular bioprostheses. It is postulated that this difference is a function of the size of the collagen fibrils in the bioprostheses and that this accounts for the very low incidence of clinically evident thromboembolism in patients with implanted dura mater valves.

Presence of antiheart and antiskeletal muscle glycolipid autoantibodies in the sera of patients with chagasic cardiopathy.

OBJECTIVE: To characterize biochemically and isolate the skeletal and heart muscle cell epitope recognized by the autoantibodies present in the serum of chronically infected Trypanosoma cruzi patients. Secondly, to use that epitope in an immunoenzymatic assay for determining differences in antibody titre among Chagas' and other protozoan and heart diseases and between asymptomatic and cardiopathic chagasic patients. DESIGN: Isolated human skeletal and heart muscle cells were treated with organic solvents, pronase, neuraminidase and sodium metaperiodate before immunofluorescence assay. Glycolipids were extracted from human skeletal muscle for ELISA. PATIENTS: Sera were collected from 155 patients with positive serology for T cruzi infection; 44 healthy blood bank donors; and from patients after heart transplantation (16 patients), during the first month after cardiac infarction (eight) or cardiotomy (10), dilated myocardiopathy (21), leishmaniasis (12), acute toxoplasmosis (four) and hyperthyroid ophthalmopathy (five). MAIN RESULTS: Immunofluorescence assay revealed that the chagasic sera recognized epitopes that appeared to be glycolipid in nature. ELISA showed that the chagasic sera contained a higher titre of antiskeletal muscle glycolipid antibodies than the control sera and that, in the chagasic population, antibody titre was significantly higher in patients with heart failure than in asymptomatic subjects or in those presenting only electrocardiographic abnormalities. CONCLUSIONS: The skeletal and heart muscle epitope recognized by antibodies present in the sera of chagasic patients has the characteristics of a glycolipid. ELISA with glycolipids extracted from human skeletal muscle indicated that chagasic patients presented a higher antibody titre and that patients with heart failure showed a titre significantly higher than those who were asymptomatic or with electrocardiographic abnormalities, suggesting that those antibodies could be immunological markers and even predictors of heart failure in Chagas' disease.

Correlation of cineangiographic and pathology findings in coronary artery disease.

In order to correlate the percent of coronary lumen reduction measured by cineangiography and by pathology, we reviewed the coronary trees of 12 patients who died of coronary heart disease. The 36 arterial segments were divided in two groups: group I showing a good correlation in its 24 segments (less than 15% difference between both methods, r = 0.90), and group II (12 segments) with a poor correlation. No significant differences were found every time there was a greater than 70% stenosis. Milder lesions have a higher rate of discrepancies, due to pathology overestimation because of collapse of the vessel and tissue shrinkage, and to the angiographic underestimation that appears when comparing the stenotic segment with a remaining presumably normal artery.

Prenylamine inhibition of adriamycin-induced myocardiopathy.

Adriamycin (ADM) is an effective antineoplastic drug. However, ADM induces alterations in cardiac function which limit the safe dose which can be administered. As it was suggested that ADM-induced cardiomyopathy is related to a calcium mediated necrosis and/or an increase in lipid peroxidation, the cardioprotective potential of prenylamine (PNL) (a well known calcium antagonistic drug) was evaluated in rabbits given chronically large doses of ADM. Twenty five rabbits were allotted to 4 groups. Group I (PNL-ADM) was given 334 +/- 82 mg of PNL and 12.2 +/- 3.8 mg of ADM, group II (water-ADM) 14.4 +/- 4.6 of ADM, group III (PNL-saline) 280 +/- 91 mg of PNL and group IV (water-saline), same doses as ADM and PNL. Rabbits were sacrificed between 38 and 65 days after the beginning of the trial. In group I weight increased only 13% and in group II, 39% (p less than 0.01). Correlation coefficients were significant for variations of weight and ADM-doses (r = 0.875). In group II 8/10 rabbits showed post-treatment electrocardiographic changes, while group I changes were found in a lesser extent (5/10). Heart homogenates from ADM-treated rabbits showed an increased lipoperoxidation (74 +/- 5 cpm/mg protein X 10(-3) as compared with the control animals (58 +/- 6 cpm/mg protein X 10(-3) (p less than 0.05), while PNL treatment did not alter myocardial lipoperoxidation. Microscopically, myocardial fibers had from mild to severe hydropic vacuolization of sarcoplasm which led to progressive myocytolysis. Myocardial damage was lower in group I (ADM-PNL), 41.7 +/- 7.6 than in group II (water-ADM), 104 +/- 10.8 (p less than 0.05). It is suggested that ADM-peroxidation effects lead to lipoperoxidation with membrane damage and increase in Ca++ permeability, the latter being counteracted by PNL.

The role of prenylamine in the prevention of adriamycin-induced cardiotoxicity. A review of experimental and clinical findings.

Experimental and clinical trials to determine the potential of prenylamine in the prevention of adriamycin-related cardiotoxicity are reviewed. In mice given 4 mg/kg body weight adriamycin, the incidence of myocardial damage after 19 days' treatment was lower than in those given adriamycin and placebo. Rabbits were given adriamycin (total dose 10.8 mg/kg body weight), adriamycin plus prenylamine (1.5 mg/kg body weight), and adriamycin plus vitamins A (250 IU) and E (40 mg) for 9-11 weeks. Adriamycin-induced electrocardiogram changes were observed to a lesser extent in animals also receiving prenylamine. Heart homogenates from adriamycin-treated animals showed enhanced hydroperoxide-initiated chemiluminescence which was not affected by the simultaneous administration of prenylamine. The extent of adriamycin-induced myocytolysis and the degree of alterations observed on electron microscopy were markedly reduced by prenylamine. In a double-blind clinical trial with 26 oncological patients, no cardiomyopathy, arrhythmia or adverse reactions were observed in the group given adriamycin plus prenylamine. In those given adriamycin plus placebo, two patients developed congestive cardiopathy and another showed severe supraventricular arrhythmias together with hypotension and dyspnoea. The mechanisms of adriamycin-related cardiotoxicity, the effects of prenylamine and the benefit from combined treatment are discussed.

[Clinical cross-sectional and epidemiologic study of Chagas disease in a rural area of the Argentinian northeast]. / Estudio transversal clínico y epidemiológico de la enfermedad de Chagas en una área rural del Nordeste Argentino.

The main goal was to know the epidemiologic, clinical, electrocardiographic and radiologic characteristics among a population of seropositives and seronegatives to Trypanosoma cruzi in a rural area of the Department of San Miguel, province of Corrientes, Argentina. One hundred and thirty-two patients of different ages: 2-79 years old were researched (58 males, 74 females). In order to make a thorough assessment clinical evaluation and cardiologic testing were carried out. Signs and symptoms consistent with heart disease, blood pressure, 12-lead ECG registry and chest x-ray (PA view) were registered. In signs and symptoms, abnormal ECG patterns and radiologic abnormalities, non-significant statistic difference were observed. Although we were unable to find a significant relationship between chagasic infection and a higher prevalence for heart disease, it is important to stress the fact that 54.0% of the studied population was largely composed of very young patients whose ages were less than 20 years old, and 45.0% of those older than 41 years showed ECG abnormalities.

Clinical manifestations of peripheral nervous system involvement in human chronic Chagas disease.

We conducted a clinical and electromyographical study in patients with Chagas' disease in the indeterminate or chronic stages of the illness. Altogether 841 patients were examined. Only 511 were admitted within the protocol; the remainder patients were rejected because they showed other causes able to damage the nervous system. Fifty two (10.17%) out of the 511 patients showed signs and symptoms of peripheral nervous system involvement in the form of sensory impairment and diminished tendon jerks suggesting the presence of neuropathy. Forty five of them were submitted to a conventional electromyographical examination. Fifteen of them showed normal results, while the remainder 30 disclosed a reduced interference pattern, being most of the remaining motor unit potentials fragmented or poliphasic, reduced sensory and motor conduction velocities and diminished amplitude of the sensory action potential. The findings suggest that some chagasic patients in the indeterminate or chronic stages of the disease may develop a clinical mild sensory-motor peripheral neuropathy.

Morphometry of skeletal muscle involvement in mice infected or preimmunized with live attenuated Trypanosoma cruzi.

A morphometric study was undertaken in the quadriceps muscle of Swiss mice in order to assess the effects of immunization with attenuated T. cruzi upon tissue lesions. interfascicular lymphocytic infiltration, presence of amastigote nests, vascular lesions, degeneration and fibrosis were evaluated independently. Each of these alterations was drastically prevented in preimmunized animals. These results indicate that immunity against T. cruzi not only reduces circulating parasites but also clears most of the organic damage caused by infection.

Myocardial involvement in Cavia porcellus naturally infected with Trypanosoma cruzi.

This paper describes the myocardial involvement analyzed by histopathological examination in rural Cavia porcellus during natural T. cruzi infection. Four Cavia porcellus of both sexes were bred in a house free of Triatoma infestans. In contrast, four animals were born and lived in a rural yard colonized by T. infestans. Autopsies were performed at 6-9 months of age, in animals weighing 550 to 750 grams. The naturally infected Cavia porcellus presented moderate and severe lymphocyte and plasmocyte infiltrates, focally or diffusedly distributed. Replacement of myocytes both in atria and ventricles was often found and consisted of loose or dense connective tissue infiltration. Regarding the conducting system, polymorphonuclear cell infiltrates were observed in the A-V node and in the left bundle branch. Uninfected Cavia porcellus did not show these lesions. Typical chagasic cysts were not found in the naturally infected Cavia porcellus hearts. Parasitism was not observed in the skeletal muscles. It is concluded that naturally infected Cavia porcellus develop consistent lesions similar to those described in human chronic chagasic myocardiopathy. The high susceptibility of naturally infected Cavia porcellus must be taken into account when these animals are used in studies regarding chronic chagasic myocardiopathy.

Panarteritis precipitating extensive circumferential acute myocardial infarction. A case report.

It is widely known that other causes than recent coronary thrombosis may precipitate acute myocardial infarction in the presence of coronary atherosclerosis. A 48 year old male patient was admitted due to acute coronary insufficiency. The ECG showed anterolateral necrosis and lateral ischemia. Despite medication angina persisted and he died immediately after coronary angiography. At autopsy, established coagulation necrosis was observed in the internal half and the subendocardium of the lateral and posterior walls, of the left ventricle. Early coagulation necrosis occupied the inner half of the anterior, posterior and septal walls. Severe atherosclerotic coronary lesions were found in all major coronary trunks. An extensive panarteritis, involving extra and intramyocardial branches, consisting of mononuclear cells and prominent edema, was observed. A mixed mechanism may be invoked to explain the extensive myocardial necrosis: panarteritic infiltrates and extensive edema and humoral-induced coronary spasm.