Endothelial progenitor cells are associated with plasma homocysteine in coronary artery disease.

OBJECTIVE

Little is known about the association between plasma homocysteine (Hcy) and endothelial progenitor cells (EPCs) in coronary artery disease (CAD).

METHODS

Blood mononuclear cells were isolated from CAD (n = 30) patients and non-CAD controls (n = 30). Flow cytometric analysis and an in vitro culture system was used to evaluate the number and function of the EPC. Plasma homocysteine (Hcy) concentration was measured by an automated fluorescence polarization immunoassay.

RESULTS

Hcy level was higher in CAD than in non-CAD (13.69 +/- 4.48 vs 9.34 + 2.31 pmol/L, P < 0.01). The number of circulating EPCs from CAD was decreased compared with non-CAD (58.7 +/- 10.6 vs. 94.3 +/- 15.1 cells/ml, P < 0.01). This decrease of EPCs in CAD was also detected (33.5 +/- 6.9 vs. 55.9 +/- 9.7 EPCs/x200 field; P < 0.01) in an in vitro culture system. The numbers of circulating and differentiated EPCs were both inversely correlated with Hcy. EPCs from CAD were significantly impaired in their migratory capacity and ability to adhere to fibronectin.

CONCLUSIONS

We observed the correlation between Hcy level and EPC number, and also found an increased Hcy level in CAD patients. It will be interesting to reveal the underlying mechanisms contributing to the correlation and examine the possible causal relationship between Hcy levels and CAD.