EXPRESSION OF MAJOR HISTOCOMPATIBILITY COMPLEX ANTIGENS AND ADHESION MOLECULES IN HEARTS OF PATIENTS WITH CHRONIC CHAGAS-DISEASE

We have previously reported that heart lesions in patients with chroni c cardiac Chagas' disease are composed predominantly of granzyme A+, c ytolytic CD8+ T lymphocytes. We now pursue this study in the immunopat hology of chronic chagasic cardiomyopathy by investigation of the expr ession of HLA antigens, and adhesion molecules in the hearts of seven chagasic patients with cardiac disease, two asymptomatic chagasic pati ents, and seven normal controls. Comparative immunohistochemical analy ses show that HLA-ABC antigen expression is enhanced on the myocardial cells of chagasic patients with chronic cardiomyopathy, suggesting a possible role for these cells as targets for the CD8+ cytolytic lympho cytes dominant in these lesions. The HLA-DR antigens are not observed on myocardial cells, but are consistently upregulated on the endotheli al cells in the hearts of patients with chronic chagasic cardiomyopath y. Intercellular adhesion molecule is expressed by endothelial cells o f both chagasic and nonchagasic individuals, but E-selectin was detect ed only on vessels of hearts from chagasic patients who had chronic ca rdiomyopathy. Most of the lymphocytes in these lesions express lymphoc yte function antigen-1 (LFA-1), CD44, and very late antigen-4, and a f ew display weak expression of LFA-3. We propose that the expression of these adhesion molecules and major histocompatibility complex antigen s by endothelial cells, myocardial cells, and lymphoid cells in these lesions contribute to the pathogenesis of chronic chagasic cardiomyopa thy.