alpha 4 Integrins and sialyl Lewis x modulation in chronic Chagas disease:Further evidence of persistent immune activation

We have previously shown that titers of soluble platelet selectin (s-P-sele ctin) and soluble vascular cell adhesion molecule-1 (s-VCAM-1) were increas ed in sera of patients with chronic Trypanosoma cruzi infection. In this st udy, we analyzed the expression of CB49d-integrins, that bind to VCAM-1, an d sialyl Lewis x (SLe(x)), which binds selectins, in peripheral blood lymoh ocytes of 27 patients with Chagas' disease at different levels of disease s everity, Patients with a mild form of Chagas' disease showed a lower number of CD-49d(+) cells, in comparison with those with severe chronic cardiopat hy, Decreased levels of CD49d(+) cells were detected in CD3(-) cell populat ions. Conversely, SLe(x) expression was found to be decreased in patients w ith severe Chagas' disease, Levels of soluble platelet endothelial cell adh esion molecule-1 (s-PECAM-1) were significantly increased in the plasma of patients with seven Chagas' disease while unaltered levels of MCP-1 were re corded. These data show that VCAM-1 and P-Selectin ligands are differential ly expressed during the chronic phase of the Trypanosoma cruzi infection, T hese findings also reinforce a role of the P-selectin/SLe(x) adhesion pathw ay rather than very late antigen-4 (VLA-4)/VCAM-1, in the pathogenesis of C hagas' disease.