Circulating apoptotic progenitor cells: a novel biomarker in patients with acute coronary syndromes.

BACKGROUND: Progenitor CD34 cells are capable of differentiating into endothelial cells and play a role in neoangiogenesis. Circulating CD34+ cells and endothelial progenitor cells are increased in acute coronary syndrome (ACS) patients possibly because of peripheral mobilization. We tested the hypothesis that circulating apoptotic progenitors are detectable in healthy subjects and altered in ACS patients. METHODS AND RESULTS: Peripheral blood mononuclear cells were isolated by Ficoll density gradient from 53 patients with ACS undergoing coronary angiography and 27 healthy subjects. Apoptosis in progenitor CD34+ cells was assessed using the Annexin V-PE/7-AAD detection kit, and fluorescence-activated cell sorter analysis was performed with triple staining for CD34, annexin-V, and 7-AAD. The percentage of apoptotic CD34+ progenitors was determined in the 2 subject groups and correlated with clinical characteristics. The percentage of apoptotic CD34+ progenitor cells was significantly increased in patients with ACS as compared with healthy subjects and was associated with the extent of coronary stenosis by angiography. There was no significant correlation between apoptotic progenitor CD34+ cells and the other parameters that we examined (age, smoking, hypertension, hyperlipidemia, diabetes mellitus, ejection fraction, creatinine levels, or taking any of the various medications, including beta blockers, thiazides, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, calcium blockers, nitrates, or statins). CONCLUSION: We established for the first time to our knowledge an assay to detect circulating apoptotic progenitor cells using fluorescein isothiocyanate-anti-CD34 MAb, annexin V-PE, and 7-AAD and found that apoptotic CD34+ cells are increased in ACS patients and in patients with more extensive coronary artery disease. This novel assay may shed new light on the factors governing the hemostasis of progenitor CD34+ cells.

Comparative analysis of the predictive power of different endothelial progenitor cell phenotypes on cardiovascular outcome.

AIM: To compare the predictive power of different endothelial progenitor cell (EPC) phenotypic markers for future cardiovascular events. METHODS: Peripheral blood was collected from 76 consecutive patients with acute coronary syndromes (ACS) who underwent percutaneous coronary intervention in our institute. The various EPC phenotypes of peripheral blood mononuclear cells were CD34+CD133+, CD34+KDR+, and CD 133+KDR+. The outcome endpoint included cardiovascular mortality, recurrent ACS, and hospitalization for decompensated heart failure during a 24-mo follow-up period. RESULTS: CD34+CD133+ cells (P = 0.034), but not CD34+KDR+ (P = 0.35) or CD 133+KDR+ cells (P = 0.19), were found to predict recurrent ACS. We found no correlation between EPCs measured by any of the three phenotypic combinations of accepted CD markers and the total combination of these separate outcomes. CONCLUSION: The EPC CD34+CD133+ phenotype, but not the CD34+KDR+ or the CD 133+KDR+ phenotypes, is predictive of future adverse cardiovascular outcomes.