Dendritic cells are potent antigen-presenting and immune modulating cells that have been implicated in the development of atherosclerosis. In human blood, two distinct lineages are distinguished: plasmacytoid dendritic cells and myeloid dendritic cells. Although dendritic cells have been described in atherosclerotic plaques, no information exists concerning circulating blood dendritic cells in atherosclerosis. This study aims to evaluate the number of circulating dendritic cells in patients with coronary artery disease. The relation with the extent of coronary artery disease, the clinical syndrome and with a marker of inflammation will be documented.Methods
Patients with angiographically proven coronary artery disease (n=18) and age and sex-matched controls (n=18) were included. Myeloid dendritic cells and plasmacytoid dendritic cells were detected with the specific blood dendritic cell antigens, blood dendritic cell antigen-1 and blood dendritic cell antigen-2, respectively.Results
Absolute and relative numbers of circulating plasmacytoid dendritic cells were significantly lower in patients with coronary artery disease (5722±601/ml and 0.08±0.01%) than in controls (12640±1289/ml and 0.21±0.02%). Plasmacytoid dendritic cells were more decreased in patients with troponin-positive unstable coronary syndromes than in patients with low troponin values, and tended to be lower in more extensive coronary artery disease. Absolute myeloid dendritic cells numbers tended to be reduced in patients, whereas relative numbers were significantly decreased: 11 857±1895/ml versus 15 226±928/ml and 0.17±0.03% versus 0.26±0.01% in controls.Conclusions
The present study shows a significant decrease of circulating blood dendritic cell antigen-2 positive plasmacytoid dendritic cells in patients with coronary artery disease. The decrease tended to be more pronounced in unstable coronary syndromes and extensive coronary artery disease, suggesting a possible role of dendritic cells in plaque progression and rupture.