Different profile of endothelial cell apoptosis in patients with Klinefelter's syndrome

The aim of this study was to evaluate the effects of testosterone (T) therapy on the sexual function of middle-aged patients with acquired pre-pubertal hypergonadotropic hypogonadism (HrHy) and patients with Klinefelter syndrome (KS).

A selected series of 35 middle-aged hypogonadal patients, including those who had recently been observed during andrological counseling (extracted from our database) and had not yet begun hormonal treatment, was recruited for this evaluation. This series of patients included 20 patients with acquired prepubertal HrHy and 15 KS patients who were matched by age and body mass index. All patients underwent an andrological evaluation, which included the administration of the International Index of Erectile Function 5 (IIEF-5) questionnaire and the evaluation of penile echo color Doppler. In addition, by flow cytometry we evaluated the serum levels of apoptotic endothelial microparticles (EMPa) and the vitronectin receptor (VR) at baseline and 6 months after the onset of T therapy.

After 6 months of T therapy, patients with HrHy demonstrated mean IIEF-5 scores and a peak systolic velocity that were significantly greater and a mean acceleration time that was significantly lower (p<0.05) than those of patients with KS (p<0.05). In addition, patients with HrHy showed mean EMPa values and VR serum concentrations that were significantly lower than those of patients with KS (p<0.05). KS patients showed significantly improved IIEF-5 scores and Doppler parameters (p<0.05) but not EMPa or VR serum concentrations following treatment.

These results indicate that erectile dysfunction in KS can improve with T therapy, although this improvement is more profound in HrHy patients, and these results also suggest that T therapy does not improve the severity of endothelial cell apoptosis in KS patients.