Proliferation and activation of vascular endothelial cells in epiretinal membranes from patients with proliferative diabetic retinopathy. An immunohistochemistry and clinical study.

In the present study, we investigated the status of proliferation and activation of vascular endothelial cells in epiretinal membranes from patients with proliferative diabetic retinopathy (PDR) by means of immunohistochemical techniques and compared the findings with the main clinical features of the patients. The results showed that of 21 vascularized membranes, 17 (81%) contained proliferating endothelial cells (positive for proliferating vascular endothelial cell marker EN 7/44) and 19 (90%) were positive for endothelial cell activation marker anti-VCAM-1; Furthermore, by using a double-staining technique we found that in 15 of the 17 cases (88%) the proliferating vascular endothelial cells were activated (expressing VCAM-1). Of the 18 type I diabetics, 15 (83%) contained activated proliferating endothelial cells, whereas in the 3 type II patients, only 1 membrane contained activated proliferating endothelial cells, Preoperatively, 18 patients had severe vitreous hemorrhage, among whom 15 (83%) contained proliferating endothelial cells, which were activated in 13 cases, and 16 patients had tractional retinal detachment, among whom 12 contained proliferating endothelial cells, which were activated in 11 cases. In all, 7 patients (33%) had vitreous rebleeding within 8 months postoperatively, whose membranes in 6 cases contained proliferating and activated endothelial cells. In contrast, of the 4 patients who were negative for EN 7/44, none had rebleeding, and of the 6 patients who were negative for EN 7/44 and anti-VCAM-1, only 1 had rebleeding.(ABSTRACT TRUNCATED AT 250 WORDS)