High ratio of myeloid dendritic cells to plasmacytoid dendriti...

BACKGROUND: Dendritic cells (DCs) stimulate T-cells to participate in the inflammatory processes that promote the destruction of vulnerable plaques. The relationship between circulating levels of myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) in patients with acute coronary syndrome (ACS) was evaluated. METHODS AND RESULTS: Blood samples were obtained from 39 patients with ACS, 41 patients with stable angina pectoris (SAP) and 43 controls. The proportion of mDCs tended to be lower in the ACS group than in the SAP group and controls. Interleukin-12 levels associated with mDCs were significantly higher in the ACS group than in control group. The proportion of pDCs was significantly lower in the ACS groups than in the other two groups. Interferon-alpha levels secreted by pDCs, however, were not significantly different among the 3 groups. The ratio of mDCs to pDCs >or=4 is an important value for distinguishing ACS from SAP patients and control patients through receiver operating characteristic analysis (sensitivity; 85.0%, specificity; 83.4%). CONCLUSIONS: The ratio of mDCs to pDCs may be a useful marker for detecting ACS and the existence of vulnerable plaques.