Submitted by Luis Ricardo Andrade da Silva (lrasilva@uefs.br) on 2016-02-12T23:10:51Z No. of bitstreams: 1 M?rcia Maria Noya Rabelo - Disserta??o.pdf: 26908510 bytes, checksum: 90ce9ed15229c185d93e1b1379da4d1a (MD5) / Made available in DSpace on 2016-02-12T23:10:51Z (GMT). No. of bitstreams: 1 M?rcia Maria Noya Rabelo - Disserta??o.pdf: 26908510 bytes, checksum: 90ce9ed15229c185d93e1b1379da4d1a (MD5) Previous issue date: 2011-03-31 / INTRODUCTION: Chagas disease, caused by the protozoan Trypanosoma cruzi, is one of the most important causes of heart failure in America. Alternative therapies have been investigated as potential therapeutic options for patients with this disease. This study evaluated the effects of therapy with human immunoglobulin in an experimental model of chronic chagasic cardiomyopathy. METHODS: C57BL/6 mice were infected with 1000 trypomastigotes of the Colombian strain of T. cruzi, and after eight months of infection were treated with intravenous human immunoglobulin or albumin (control). Before and after 2 months of treatment, infected animals and normal controls underwent cardiac evaluation including electrocardiogram, echocardiography and treadmill test. The immunoglobulin and albumin groups were treated, respectively, with 1 mg/kg/day of human immunoglobulin or albumin, intraperitoneally, for five consecutive days. All animals were sacrificed under anesthesia, after 2 months of treatment, for histopathological analysis of the heart. RESULTS: No improvement was observed in cardiovascular function in animals treated with immunoglobulin compared to animals treated with albumin. There was an increasing in the number of animals with complete atrioventricular block in the immunoglobulin group. However, sections of hearts in immunoglobulin group had a significantly reduced number of inflammatory cells (p <0,01) and area of fibrosis (p <0,001), compared to animals treated with albumin. In animals treated with immunoglobulin, there was evidence of arteritis marked with immune complex deposition in the intima of arterioles. The concentrations of serum cytokines were increased in the group treated with immunoglobulin in comparison to the other groups (uninfected and treated with albumin mice). When considering cytokines production in heart extract, there were no differences observed in production of IFN-?, TNF-? and IL-10 between the groups treated with immunoglobulin and albumin. CONCLUSION: Thus, we concluded that immunoglobulin therapy has neither not shown anti-inflammatory efficacy nor improvement in cardiovascular function in a murine model of chronic chagasic cardiomyopathy. / INTRODU??O: A doen?a de Chagas, causada pelo protozo?rio Trypanosoma cruzi, ? uma das mais importantes causas de insufici?ncia card?aca na Am?rica. Terapias alternativas v?m sendo investigadas como poss?veis op??es terap?uticas para pacientes portadores desta doen?a. Neste estudo foram avaliados os efeitos da terapia com imunoglobulina humana em um modelo experimental de cardiomiopatia chag?sica cr?nica. M?TODOS: Camundongos C57BL/6 foram infectados com 1000 tripomastigotas da cepa Colombiana de T. cruzi e, ap?s oito meses de infec??o, foram tratados com imunoglobulina ou com albumina humanas (controle). Antes e ap?s 2 meses do tratamento, os animais chag?sicos e controles normais foram submetidos ? avalia??o card?aca, incluindo eletrocardiograma, ecocardiograma e teste ergom?trico. Os grupos tratados com imunoglobulina e albumina receberam, respectivamente, 1 mg/Kg/dia de imunoglobulina humana ou albumina, via intraperitoneal, por cinco dias consecutivos. Todos os animais foram sacrificados sob anestesia ap?s 2 meses de tratamento, para an?lise histopatol?gica do cora??o. RESULTADOS: N?o foi observada uma melhora da fun??o cardiovascular no grupo tratado com imunoglobulina quando comparado ao grupo tratado com albumina. Houve um aumento do n?mero de animais com bloqueio atrioventricular total no grupo imunoglobulina. No entanto, sec??es de cora??es de camundongos do grupo imunoglobulina apresentaram uma redu??o significativa do n?mero de c?lulas inflamat?rias (p< 0,01) e da ?rea de fibrose (p< 0,001) em compara??o com animais chag?sicos tratados com albumina, sendo que nos animais tratados com imunoglobulina foi evidenciada a presen?a de arterite acentuada, com dep?sito de imunocomplexos na camada ?ntima arteriolar. As concentra??es de 12 citocinas s?ricas foram aumentadas no grupo tratado com imunoglobulina em rela??o aos demais grupos (n?o infectados e tratados com albumina). Quando avaliada a produ??o, em extrato de cora??o, de IFN-?, TNF-? e IL-10, n?o foram observadas diferen?as entre os grupos tratados com imunoglobulina e albumina. CONCLUS?O: Deste modo, conclu?mos que a terapia com imunoglobulina humana n?o demonstrou efic?cia anti-inflamat?ria nem induziu a melhora da fun??o card?aca no modelo murino de cardiomiopatia chag?sica cr?nica.