Expression of cell adhesion molecules in dilated cardiomyopathy -: Evidence for endothelial activation in inflammatory cardiomyopathy

Background-Dilated cardiomyopathy (DCM) is pathogenically linked to inflammatory cardiomyopathy (InfCM), which is characterized by intramyocardial infiltration. The transendothelial migration of immunocompetent cells is mediated by cell adhesion;molecules (CAMs). Methods and Results-We investigated the expression pattern of CAMs (immunoglobulin superfamily, 32 selectins, and beta(1)- and beta(2)-integrins) in endomyocardial biopsies from DCM patients (n=152; left ventricular ejection fraction <40%) using immunohistochemistry. Whereas few specimens obtained at autopsy (controls; n=14) presented enhanced expression regarding single endothelial CAMs (human leukocyte antigen [HLA] class I, 7%; HLA-DR, 14%; CD29, 14%), none demonstrated concurrent abundance of >3 CAMs (inflammatory endothelial activation), nor did any control tissue prove positive for InfCM (>7.0 CD3+ lymphocytes per 1 mm(2)). In comparison, 64% (n=97) of the DCM biopsies were evaluated positive for InfCM and 67% (n=101:) for inflammatory endothelial activation, respectively, Whereas expression of HLA class I, HLA-DR, intercellular cell adhesion molecule-1, and CD29 was distributed homogeneously within a patient's serial sections, immunoreactivity:of vascular cell adhesion molecule-1, lymphocyte function antigen-3, and the selectins was accentuated on single vascular endothelia. Sixty-six percent of the DCM biopsies presented CD29 abundance also within the extracellular matrix and the sarcolemma. CD62P and CD62E were present in 16% and 40% of the DCM patients, respectively. Endothelial CAM representatives correlated with one another (P<0.05), except for CD62P with HLA. Endothelial CAM expression correlated with intramyocardial infiltrates phenotyped by the corresponding counterreceptors. Conclusions-Inflammatory endothelial activation is present in 67% of DCM patients. Because CAM expression correlates with the immunohistological diagnosis of InfCM and counterreceptor-bearing intramyocardial infiltrates, evaluation of endothelial CAMs might be of diagnostic significance in InfCM.