Arterial Erectile Dysfunction and Peripheral Arterial Disease: Reliability of a New Phenotype of Endothelial Progenitor Cells and Endothelial Microparticles

The aim of this study was to evaluate whether the blood concentrations of a new immunophenotype of circulating late endothelial progenitor cells (EPC) and endothelial microparticles (EMP) varies in patients with arterial erectile dysfunction (aED) and abnormalities in other arterial districts. To accomplish this, cavernous artery peak systolic velocity (PSV), acceleration time (AT), and intima-media thickness (IMT) were determined after intracavernous administration of alprostadil by echo-color Doppler in 80 consecutive patients (age range, 50-75 years). Fifteen patients had aED alone (group A) and served as controls; 22 had aED plus atheroma plagues and/or increased IMT of the common carotid artery (group B); 20 had aED plus lower limb artery abnormalities (group C); and 23 had aED plus carotid and lower limb artery abnormalities (group D). EPC and EMP blood concentrations were evaluated by flow cytometry. Blood mononuclear cells with the immunophenotype CD45(neg)/CD34(pos)/CD144(pos) were defined as EPCs, whereas CD45(neg)/CD144(pos)/annexin V-pos cells were defined as EMPs. Group B and C patients had a similar PSV, AT, and IMT at the level of the cavernous arteries. Their PSV values were significantly lower and mean values of AT and IMT significantly higher compared with group A patients. Patients of group D had a significantly lower PSV and significantly higher AT and IMT compared with all other groups. As far as serum concentrations of EPCs and EMPs, group D patients had significantly higher EPC and EMP mean values compared with all other groups. Group B and C patients had similar EPC and EMP values. This study showed that a more generalized peripheral atherosclerotic process is associated with a more severe penile artery insufficiency and endothelial dysfunction. Moreover, this study confirms the diagnostic reliability of the immunophenotype of EPCs and EMPs chosen in the clinical practice.