The Target Cells in Vascularized Bone Allografts

Abstract

Immediate vascularization of bone allografts by microsurgical anatomoses of donor and host arteries and veins is a theoretically appealing way to avoid problems of prolonged nonviability inherent in massive bone transplantation [1, 22, 24]. This includes nonunion, sepsis, and fatigue fracture [14–16, 18–20, 23, 25] until the grafts are revascularized by host vessels and repopulated by host osteocytes. In order to study the immunological consequences and sequelae of the primary vascularization of bone, transplanted as an organ, a genetically defined heterotopic rat model has been developed. The question was whether the immunologic events and target tissues are different in transplantation across strong and weak barriers, and whether transplantation across a weak genetic barrier would result in a less intense host response. To examine these, we carried out a histologic and histochemical analysis of the acute rejection process in vascularized bone allografts transplanted across both strong and weak histocompatibility barriers.