Abstract 387: Chronic Pravastatin Therapy Increases Outgrowth Endothelial Progenitor Cells in Patients with Stable Coronary Artery Disease
Purpose: Previous studies have shown that early and outgrowth endothelial progenitor cells (EPCs) can be detected in peripheral blood. Furthermore, statin therapy can increase EPC mobilization into the peripheral blood. However there are no data concerning the long term effects of statin treatment on this phenomenon. Our aim was to investigate whether EPCs can be detected and characterized in patients (pts) with at least 4 weeks statin therapy.
Methods: 2 groups of pts were matched for sex, age and treatment. The statin (+) group (n=7) included pts with stable coronary artery disease (CAD) treated with pravastatin 40mg for at least 4 weeks. The statin (−) group (n=7) included pts with stable angina without statin therapy. Mononuclear cells from all pts were assessed for progenitor cell (CD34, CD34/CD144 and CD34/CD117) and endothelial phenotype (VEGF-R2, CD31) by flow cytometry and were cultured to determine the number and the type of EPCs.
Results: The table⇓ shows the % of positive circulating progenitor cells CD34+, CD34+/CD144+ and CD34+/CD117+. There was a significantly higher number of circulating progenitor cells in the statin (+) group. The culture showed that circulating early EPCs were CD146+ and CD45+ and were also significantly higher in the statin (−) group. Surprisingly, circulating outgrowth EPCs were only found in the statin (−) group. Phenotyping of cultured cells showed that cells from outgrowth EPC colonies clearly had an endothelial phenotype CD31+, VEGF-R2+, CD34+ in contrast to cells from early EPC colonies (VEGF-R2low, CD34−, CD45+).
Conclusions: These results show that (i) EPCs can be found in the peripheral blood of CAD pts treated up to 4 weeks with 40 mg of pravastatin, (ii) long term statin therapy raises EPC levels by increasing outgrowth EPC population without affecting early population levels and (iii) the phenotype of early EPC is different from that of outgrowth EPCs suggesting that early EPCs are not endothelial but hematopoietic in origin.