Identification of Dendritic Cells in ePTFE Grafts Explanted from Humans

Abstract

Following implantation different cell types interact with synthetic vascular prostheses resulting in a complex immuno-inflammatory response. Dendritic cells are responsible for actuating the primary T-lymphocyte immune response in various pathological conditions by their role as antigen-Dresenters This study aimed at examining whether dendritic cells accumulate within small dimeter expanded polytetrafluoroethylene (ePTFE. Goretex®) grafts explanted from humans. Segments of expanded polytetrafluoroethylene were explanted from 11 patents (6 male S female) aged between 60 and 83 years (mean 70.7 years) at secondary or revision bypass operatlon The graft implant duration varied from 4 months to 12 years (mean 40.5 months). Dendritic cells were identified immunohistochemically using S-100 antibody, as well as by electron microscopy. Immunohistochemical examination showed that all 11 explanted synthetic grafts contained S-100⁺ cells colonising both the synthetic matrix itself, and the adjacent perigraft tissue. Electron microscopic analysis confirmed the presence of cells with a characteristic dendritic cell morphology within the grafts. Dendritic cells which accumulated within synthetic grafts were found to co-localise with T-lymphocytes. Based on these observations we speculate that dendritic cells may be involved in the immuno-inflammatory responses following the Implantation of synthetic vascular prostheses through their interaction with T-lymphocytes.