Decreased myocardial dendritic cells is associated with impaired reparative fibrosis and development of cardiac rupture after myocardial infarction in humans

Background-dendritic cells (dc) play pivotal roles in regulating the immune system and inflammatory response. we previously reported dc infiltration in the infarcted heart and its immunoprotective roles in the post-infarction healing process after experimental myocardial infarction (mi). however,its clinical significance has not been determined. methods and results-the degree of dc infiltration and its correlation with the post-infarction healing process in the human infarcted heart were investigated in 24 autopsy subjects after st-elevation mi. patients were divided into two groups according to the presence (n=13) or absence (n=11) of cardiac rupture. the numbers of infiltrated dc and macrophages and the extent of fibrosis in the infarcted area were examined. in the rupture group,cd68+ macrophage infiltration was increased and cd209+ dc,and cd11c+ dc infiltration and the extent of reparative fibrosis were decreased compared with the non-rupture group,under matched baseline characteristics including the time from onset to death and use of revascularization. furthermore,there was a significant positive correlation between the number of infiltrating cd209+ dc,and cd11c+ dc and the extent of reparative fibrosis. conclusions-decreased number of dc in human-infarcted myocardial tissue was associated with increased macrophage infiltration,impaired reparative fibrosis,and the development of cardiac rupture after mi. these findings suggest a protective role of dc in post-mi inflammation and the subsequent healing process. © 2014 the authors.