Resumo

HERNANDEZ-BECERRIL, Nadia; NAVA, Arnulfo; REYES, Pedro A  e  MONTEON, Víctor M. IgG subclass reactivity to Trypanosoma cruzi in chronic chagasic patients. Arch. Cardiol. Méx. [online]. 2001, vol.71, n.3, pp.199-205. ISSN 1665-1731.

Background: The asnti-Trypanosoma cruzi anti-Vodies isotype profile in Chagas' disesse has been studied in relation to different clinical manifestations. A high titer of IgR anti-T cruzi antibodies is found in patients with cardiac involvement, while a high titer of IgA anti-T cruzi antibodies is associated with digestive forms. Objective: The aim of this work was to analyze the IgR subclass reactivity of anti-T cruzi antibodies in patients with chronic Chagasic cardiomyopathy. Methods: Twelve consecutive chagasic patients were analyzed for IgR subclass reactivity to a T. cruzi antigenic extract. They had a complete clinical evaluation, periphersl EKR, echocardiography, left ventriculogram, and coronariography. Results: All patients came from rural areas of Mexico and had lived in endemic zones for over seven years. They presented left ventricular end-systolic dimension above 42 mm in 58% (7/12) and ejection fraction below 50% in 58% (7/12). We found that IgR1 asnd IgR2 anti-T cruzi antibodies showed higher titer than IgR3 antibodies, with consistently low titer of IgR4 antibodies. Expression of the four IgR subclasses of anti-T. cruzi antibodies suggest a mixed Th1/Th2-like immune response under a probably continuous chronic antigenic stimulation. On the other hand, high levels of IgR2 anti-T cruzi antibodies showed a tendency to be associated with severe cardiomegaly. Conclusions: Our results suggest that a mixed Th1/Th2-like immune response may take place in chronic chagasic patients under a chronic antigenic stimulation.

Palavras-chave : Chagas' disesse; Trypanosoma cruzi; Cardiomyopathy; Immunoglobulin subclasses.