Objective:The process of myocardial infarction is generally characterized by the activation of host immune cells and the occurrence of inflammation. However, it is unknown which immune cells are preferentially activated and participated into the progression of myocardial infarction. Methods:A total of 55 patients with myocardial ischemia including 13 of stable angina ( SA) ,25 of unstable angina (UA) and 17 of acute myocardial infarction (AMI) as well as 12 of healthy controls (HCs) were enrolled in the study. The frequency and the immune activation marker CD38 expression by peripheral CD3 T cells,CD4 T cells,CD8 T cells,CD4+NKT cells, CD4- NKT cells, CD3-CD56+ NK cells and B cells were comprehensively analyzed. Results:There was no significant difference in the frequencies of these immune cell subsets in peripheral blood among these four groups. Importantly,it was found that CD38 expression was significantly increased on CD8 T cells,NKT cells and NK cells in patients with acute coronary syndromes ( ACS) including UA and AMI patients as compared with those in SA and HC subjects. These data indicated that multiple immune cells were activated in ACS patients,which were possibly participated into the pathogenesis of ACS. Conclusion:The activation of multiple immune cells was closely associated with the progression and outcome in ACS patients. This study provides immune hyper-activation mechanism underlying the development of ACS and may favor for finding a novel immune marker to predict the progression of ACS.