Increased circulating CD3 + /CD31 + T cells in patients with acute coronary syndrome

The number of circulating endothelial progenitor cells (EPCs) is considered to be a surrogate marker for coronary artery disease (CAD). Recent studies have identified a novel T-cell subset labeled with CD3 + /CD31 + , which is necessary for EPC colony formation and constitutes the central cluster. However, the clinical relevance of the CD3 + /CD31 + T cells in CAD remains unclear. We sought to clarify whether circulating CD3 + /CD31 + T cells are increased in patients with acute coronary syndrome (ACS). Circulating CD3 + /CD31 + T cells were determined in 16 ACS patients undergoing emergency percutaneous coronary intervention (PCI) and in 16 control subjects with angiographically normal coronary arteries. Although no differences between the groups were found in baseline patient characteristics, the ratio of circulating CD3 + /CD31 + T cells before PCI was higher in ACS patients as compared with that in control subjects (51.8 % ± 7.8 % vs 31.8 % ± 9.6 %, respectively; P < 0.001). The increased ratio of CD3 + /CD31 + T cells in ACS patients was not altered 24 h after PCI, but became comparable with that in control subjects within 6 months after PCI. These results suggest that mobilization of CD3 + /CD31 + T cells occurs in ACS, but is no longer detectable at 6 months after PCI.