CHARACTERIZATION OF INFLAMMATORY INFILTRATES IN CHRONIC CHAGASIC MYOCARDIAL LESIONS - PRESENCE OF TUMOR NECROSIS FACTOR-ALPHA+ CELLS AND DOMINANCE OF GRANZYME A+, CD8+ LYMPHOCYTES

The inflammatory infiltrates in the heart lesions of chronic chagasic cardiomyopathy are composed predominantly of small lymphocytes with ad mixed macrophages, plasma cells, and segmented leukocytes. The phenoty pes of the lymphoid cells in these infiltrates of human Chaps' disease have not been previously detailed. We used a panel of monoclonal and polyclonal antibodies to immunohistochemically characterize the inflam matory cells in frozen and fixed cardiac tissues from autopsied patien ts with severe chronic chagasic cardiomyopathy. In all cases, the infl ammatory lesions were dominated by CD8+ lymphocytes, many of which exp ressed granzyme A. A few macrophage-like cells that expressed tumor ne crosis factor-a were observed in each case. Relatively few natural kil ler cells or B lymphocytes were found in the lesions. These findings i n human chagasic lesions are compatible with concepts that involve cyt olysis and fibrosis, and new experimental findings that emphasize pote ntial roles for CD8+ T cells in Chagas' disease.