Abstract 2188: Endothelial Progenitor Cells Increased after Angioplasty in Chronic Lower Limb Ischemia: a role for Inflammation
Introduction Circulating endothelial progenitor cells (EPCs) are involved in vascular homeostasis. The decrease of EPCs in atherosclerosis might reflect endothelial dysfunction and participate to vascular disease progression. We aimed to assess the number of circulating EPCs in patients with chronic lower limb ischemia (CLLI) before and after angioplasty, and the correlation to inflammation and angiogenic markers.
Methods In 14 patients with CLLI, circulating EPCs were quantified using a colony-forming unit (CFU) assay, and expressed in number of CFU-EC/mL of blood, at baseline, and 24 h and 3 months after angioplasty. In order to characterize CFU-ECs, immunostaining with endothelial specific markers (VWF, CD31 and KDR) was performed and endothelial progenitor phenotype was further confirmed by indirect immunofluorescent staining with Dil-acLDL and co-staining with BS-1 lectin. Vascular endothelial growth factor (VEGF), C-reactive protein (CRP) and interleukin-6 (IL-6) were determined on blood samples at the same time-points. In addition, the number of CFU-ECs was determined in 16 control subjects without CCLI, matched for age and sex.
Results At baseline, the number of CFU-ECs tended to be lower in patients than in controls (ns) and was negatively correlated to the number of cardiovascular risk factors (r=−0.48, p=0.006). In patients, a significant increase in circulating CFU-ECs was observed 24 hours after angioplasty, as compared to baseline (26[13.2–43.7] vs 5.6[3.2–16.8] CFU-ECs/mL, p=0.01), associated with an increase of CRP (6[4–18] vs 3.8[1.2–4.2] mg/L, p=0.006), and IL-6 (14.4[5.9–34.2] vs 2.4[1.9–4.3] pg/mL, p<0.0005), but not of VEGF (490[241–1129] vs 571[251–970] pg/mL, ns). After 3 months, the number of CFU-ECs and inflammation markers returned to baseline levels.
Conclusion A transient increase of circulating EPCs occurs early after angioplasty, associated with an increase of inflammatory reaction following angioplasty, in absence of any variation of serum VEGF levels. The clinical significance of this transient mobilisation remains to be assessed.