Characterization of the cellular immune response in chagas'disease patients / Caracterización de la respuesta inmunológica celular en pacientes con la enfermedad de chagas

RESUMO

The in vitro lymphocyte proliferative responses and some mechanisms possibly involved in immunoregulation, were evaluated in 57 patients with Chagas'disease. The patients were classified as being cardiomyophathic (CDM), with positive complement fixation tests (CFT) for T. cruzi, or as infected chagasic patients (INF) with a positive CFT but without any clinical evidence of cardiac involvement. The in vitro responses to T. cruzi antigens were significantly greater in both groups of patients than in the controls, the intensity of the reactions being greatest in CDM patients. Trypanosoma cruzi antigen-induced suppression of in vitro mitogen responsiveness was not detected in either group of Chagas'patients. The mitogenic responses to PHA of CDM patients were,in fact,significantly lower than those of healthly controls. Con A responses were normal in these patients,as was also the case in INF patients for both mitogens. Cell mixingexperiments, showed an augmentation in responsiveness to PHA by co-cultures of mononuclear cells from CDM patients with those from healthtly controls. This was not observed in combinations of cells from controls and INF patients. Due to thepossible modulatory influences of circulating immune complexes,these were also evaluated,higher levels being found in INF and CDM patients than in controls. Thesignificance of these results in the physiopathology of Chagas'is discussed