OBJECTIVETo investigate the effect of immune response mediated by antigen (oxidized low density lipoprotein, oxLDL)-specific T cells on plaque stability in coronary heart disease.

METHODSTwenty patients with acute myocardial infarction (AMI), 34 with unstable angina pectoris (UAP), 27 with stable angina pectoris (SAP) and 22 control subjects were enrolled in this study. MTS/PMS colorimetric assay was used to measure the proliferative response of the T cells to stimulation to 5 microg/ml oxLDL and detect IFN-gamma concentration produced in the proliferative response. The effect of C-reactive protein (CRP) on the proliferative response of the T cells to oxLDL and IFN-gamma concentration produced was examined in AMI group and UAP group.

RESULTSThe proliferative response of T cells to stimulation to 5 microg/ml oxLDL was significantly higher in AMI group and UAP group than in SAP group and the control group (P<0.05). IFN-gamma concentration produced in the proliferative response of the T cells was also significantly higher in AMI group and UAP group than in the other two groups (P<0.05). CRP at 10 microg/ml significantly increased the proliferative response of the T cells to oxLDL and IFN-gamma production in ACS group (P<0.001).

CONCLUSIONThe immune response mediated by the antigen-specific T cells, especially that mediated by type 1 T helper cells secreting IFN-gamma, may play an important role in the instability of plaques, and CRP may promote the inflammation of atherosclerosis through the effects on the specific immune response to oxLDL.