Detection and validation of circulating endothelial cells, a blood-based diagnostic marker of acute myocardial infarction.

BACKGROUND: Circulating endothelial cells (CECs) are markers of vascular damage that have clinical relevance in many diseases, including acute myocardial infarction (AMI), and may be predictors of treatment responses. Herein, we investigated the diagnostic and prognostic value of CEC monitoring in AMI patients and a murine model. METHODOLOGY/PRINCIPAL FINDINGS: CECs were defined as Hoechst 33342(+)/CD45(-/)CD31(+)/CD146(+)/CD133(-) in human blood samples and Hoechst 33342(+)/CD45(-/)CD31(+)/KDR(+)/CD117(-) in murine samples. To evaluate the validity and variability of our CEC detection system, peripheral blood samples of vascular endothelial growth factor-treated athymic nude mice and AMI patients were collected and subjected to intra-assay analysis. CEC detection by flow cytometry and real-time PCR were compared. Blood samples were obtained from 61 AMI patients, 45 healthy volunteers and 19 samples of the original AMI patients accepted one month treatment, via flow cytometry and expressed as a percentage of peripheral blood mononuclear cells. RESULTS: Our CEC detection method was validated and had limited variability. CEC concentrations were higher in AMI patients compared to healthy controls. One month post-treatment, CECs levels decreased significantly. CONCLUSIONS/SIGNIFICANCE: CEC levels may be useful as a diagnostic and prognostic biomarker in AMI patients.