Immunologic and ultrastructural changes during early rejection of vascularized bone allografts.
This investigation evaluated ultrastructural changes during the earliest phase of immunologic rejection of vascularized bone allografts in a genetically defined rat model. These results were correlated with the cell-mediated and humoral immunologic responses during this time period. Employing a model for heterotopic allograft transplantation, 33 rats divided into four categories were evaluated. Group I consisted of ungrafted (naive) Lewis and Brown Norway rats; group II consisted of Lewis-to-Lewis vascularized bone isografts; group III consisted of Lewis-to-Brown Norway vascularized bone allografts; and group IV consisted of Lewis-to-Brown Norway vascularized bone allografts in rats receiving cyclosporine (10 mg/kg/day). Experimental animals were sacrificed at 3, 5, and 7 days. Immunologic analysis was performed using a cell-mediated lymphocytotoxicity assay and a complement-dependent cytotoxic antibody assay. The results of this study show that rejection of vascularized bone allografts appears as early as 3 days postoperatively, with osteocytes and vascular endothelium being the first elements affected. This early rejection is probably a manifestation of the humoral response. All changes secondary to rejection were arrested by cyclosporine.
Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, Baltimore, Md.
M F
MF
Gornet
M A
MA
Randolph
B H
BH
Schofield
M J
MJ
Yaremchuk
A J
AJ
Weiland
D000818:Animals; D000917:Antibody Formation; D016025:Bone Transplantation / Q000276:immunology* / Q000473:pathology*; D003524:Cyclosporins / Q000627:therapeutic use; D004730:Endothelium, Vascular / Q000187:drug effects / Q000276:immunology / Q000648:ultrastructure; D006084:Graft Rejection / Q000187:drug effects / Q000276:immunology*; D007111:Immunity, Cellular; D010011:Osteocytes / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D051381:Rats; D011914:Rats, Inbred BN; D011917:Rats, Inbred Lew; D013997:Time Factors; D014184:Transplantation, Homologous
D003524:Cyclosporins