Human chronic chagasic myocarditis: quantitative study of CD4 + and CD8 + lymphocytes in the inflammatory infiltrate

Abstract

Myocardialexsudate CD4+ andCD8+ lymphocytes were counted in transmural left ventricular free wall frozen sections taken from 10 necropsied chronic cardiac chagasic patients. The cells were labeled with monoclonal antibodies using a streptavidin-biotin technique. We counted: 1) lymphocytes in the total exsudate (LTE) and, separately, 2) the lymphocytes touching orvery near to my oc ells (LTVNM). Lymphocytes were considered very near whenever their own nuclear shortest nuclear diameter was larger than their distance from myocells. CD8+ lymphocytes were more numerous than CD4+ lymphocytes, especially among the LTVNM. The LTE CD4/CD8 ratio was 0,37 ± 0,20, but the LTVNM CD4/CD8 ratio was smaller (0,23 ± 0,11). Among theLTE, 34 ± 11% ofCD8+ (against24 + 12% of CD4+) were LTVNM. All these differences were statistically significant. Both subtypes ofT-lymphocytes were found to have an intimate relationship with both ruptured and unruptured myocells, and parasites were not seen. These findings are in accordance with the idea that the myocardial cell lesions in the cardiac form of human Chagas' disease are mediated mainly by T- cytotoxic lymphocytes.

ARTIGOS

Miocardite chagásica crônica humana: estudo quantitativo dos linfócitos CD4+ e dos CD8+ no exsudato inflamatório

Human chronic chagasic myocarditis: quantitative study of CD4 + and CD8 +

lymphocytes in the inflammatory infiltrate

Sebastião Tostes Junior; Edison Reis Lopes; Fausto Edmundo Lima Pereira; Edmundo Chapadeiro

Endereço para correspondência

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RESUMO

Em cortes histológicos de fragmentos transmurais congelados da parede livre do ventrículo esquerdo, obtidos em necrópsias de 10 chagásicos crônicos cardiopatas, foram contados os linfócitos CD4+ e os CD8+ do infiltrado miocãrdico. As células foram marcadas com anticorpos monoclonais, usando-se a técnica estreptavidina-biotina. Contou-se: l)os linfócitos em todo o exsudato (LTE) e, separadamente, 2) os linfócitos que estavam em contato ou muito próximos das miocélulas (LCMPM). Foram considerados muito próximos aqueles linfócitos cujos núcleos distavam, dasmiocélulas, menos que seus próprios menores diâmetros nucleares. Os linfócitos CD8+foram mais numerosos do que os CD4+, principalmente entre os LCMPM. A relação CD4/CD8 foi de 0,37 ± 0,20 entre os LTE, mas foi menor quando considerados apenas os LCMPM (0,23 ± 0,11). Dentre os LTE, 34 ± 11% dos CD8+ (contra 24 ± 12% dos CD4+) eram LCMPM. Todas essas diferenças foram estatisticamente significantes. Linfócitos das duas subpopulações foram vistos em íntima relação com miocélulas íntegras ou rotas, e nãoforam observados parasitas nos cortes examinados. Estes achados concordam com a idéia de que a lesão dos miocardiócitos na forma cardíaca da doença de Chagas humana é mediada principalmente por linfócitos T citotóxicos.

Palavras-chave: Tripanosomíase cruzi. Doença de Chagas. Miocardite. Patogênese. Linfócitos T.

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ABSTRACT

Myocardialexsudate CD4+ andCD8+ lymphocytes were counted in transmural left ventricular free wall frozen sections taken from 10 necropsied chronic cardiac chagasic patients. The cells were labeled with monoclonal antibodies using a streptavidin-biotin technique. We counted: 1) lymphocytes in the total exsudate (LTE) and, separately, 2) the lymphocytes touching orvery near to my oc ells (LTVNM). Lymphocytes were considered very near whenever their own nuclear shortest nuclear diameter was larger than their distance from myocells. CD8+ lymphocytes were more numerous than CD4+ lymphocytes, especially among the LTVNM. The LTE CD4/CD8 ratio was 0,37 ± 0,20, but the LTVNM CD4/CD8 ratio was smaller (0,23 ± 0,11). Among theLTE, 34 ± 11% ofCD8+ (against24 + 12% of CD4+) were LTVNM. All these differences were statistically significant. Both subtypes ofT-lymphocytes were found to have an intimate relationship with both ruptured and unruptured myocells, and parasites were not seen. These findings are in accordance with the idea that the myocardial cell lesions in the cardiac form of human Chagas' disease are mediated mainly by T- cytotoxic lymphocytes.

Keywords: Trypanosomiasis cruzi. Chagas' disease. Myocarditis. Pathogenesis. T lymphocytes.

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REFERÊNCIAS BIBLIOGRÁFICAS

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Endereço para correspondência:

Dr. Sebastião Tostes Junior.

Curso de Pós-graduação em Patologia Humana

Hospital Escola. R. Getúlio Guarita 130

38025-440

Uberaba, MG.

Recebido para publicação em 05/04/94.

Curso de Pós-graduação em Patologia Humana da Faculdade de Medicina do Triângulo Mineiro, Uberaba, MG.

Suporte financeiro: CNPq e NIH.