Decreased expression of pigment epithelium-derived factor and increased microvascular density in ovarian endometriotic lesions in women with endometriosis

Objectives To determine whether women with endometriosis have altered expression of pigment epithelium-derived factor (PEDF) in ovarian endometriotic lesions as compared to women without endometriosis. Study design Ectopic and eutopic and normal endometrial tissues were sampled from 40 women with ovarian endometriosis and 20 control women, respectively. Endometrial PEDF expression and microvascular density (MVD) using an antibody to von Willebrand factor (vWF) and alpha-smooth muscle actin (α-SMA) were evaluated by using immunohistochemical staining. Results We detected decreased PEDF expression and increased MVD using anti-vWF and -α-SMA in ovarian endometriotic lesions in women with endometriosis compared with the control group. In women with endometriosis, the MVD using anti-vWF and -α-SMA but not PEDF expression in ovarian endometriotic lesions correlated with the size of ovarian endometriotic cysts and the severity of the disease. Moreover, the MVD using anti-vWF was negatively correlated with PEDF expression in control endometrium but not in ovarian endometriotic lesions. Conclusions Our results suggest that decreased PEDF expression and increased MVD in ovarian endometriotic lesions might play an important role in the pathogenesis of ovarian endometriosis.