OBJECTIVETo study the quantitative and functional changes of peripheral blood dendritic cells (DCs) and their subsets in the leukocyte population in patients with coronary artery disease (CHD) with different coronary artery plaques and explore the relation between DCs and coronary plaque development.

METHODSThirty CHD patients were divided into SAP (10 cases), UAP (10 cases) and ACS (10 cases) groups, with another 10 patients having negative result in coronary angiography as the control group. Intravascular ultrasound (IVUS) was performed to identify the nature of the plaques. The percentage and absolute number of peripheral blood DCs and DC subsets were measured by flow cytometry. The functional status of the DCs was analyzed by enzyme-linked immunosorbent assay (ELISA) and flow cytometry.

RESULTSIn the SAP group, IVUS found stable plaques in 8 cases and unstable plaques in 2 cases; in UAP group, 7 patients had unstable plaques, 2 had stable plaques, and 1 had plaque rupture. Plaque rupture, unstable plaques and stable plaques were found in 6, 3 and 1 patients in ACS group, respectively. In comparison with patients with stable plaques, those with unstable plaques had significantly increased percentages and number of DCs, mDCs and mDC1 (P<0.05), while the mDC2s and pDCs showed no obvious difference between them (P>0.05). The percentages and number of DCs, mDCs, mDC1s and pDCs were significantly decreased in patients with ruptured plaques (P<0.05). In peripheral blood monouclear cells cultured for 7 days, the CD83 expression was significantly higher in unstable and rupture plaque groups than in stable plaque group, and no significant difference was found between stable plaque group and the control group (P>0.05). In unstable and rupture plaque groups, co-culture with 2x10(5)/ml DCs evoked strong proliferation of the T cells in comparison with the stable plaque group, but no difference was found between the stable plaque and the control groups (P>0.05). Significantly higher levels of interleukin-2 and interferon-alpha were detected in the supernatant of the mixed lymphocyte reaction in unstable and ruptured plaque groups than in stable plaque and control groups, without obvious difference between the latter two groups.

CONCLUSIONThe percentage and absolute number of peripheral blood DCs and their functional status suggest the alterations of the coronary artery plaques in CHD patients.