Prolonged cold preservation augments vascular injury independent of renal transplant immunogenicity and function.
BACKGROUND
While prolonged cold ischemia has detrimental effects on graft survival, the mechanisms remain unclear. We tested whether or not cold preservation enhances intragraft inflammatory responses and vascular injury.


METHODS
Rat renal grafts were cold preserved in University of Wisconsin solution for 2, 4, 6, 12, 24, and 48 hours, and then transplanted into syngeneic recipients and harvested after 24 hours. Frozen sections were examined histologically and stained for vascular cellular adhesion molecule-1 (VCAM-1), platelet-endothelial cell adhesion molecule-1 (PECAM-1), major histocompatibility complex (MHC) class II, tissue factor, leukocyte function associated molecule-1 (LFA-1), very late antigen-4 (VLA-4), as well as for inflammatory cells.


RESULTS
Function did not differ between isografts preserved for shorter (2 to 6 hours) or longer times (12 to 24 hours). Neutrophil influx and that of LFA-1-positive cells showed similar increases in all groups. Compared with short preservation groups, the long preserved grafts had more VLA-4-positive ED-1+ monocytic infiltrates adjacent to vessels expressing VCAM-1 (P < or = 0.001). Increased preservation duration had no effect on infiltration with recipient ED-2+ macrophages, MHC class II-positive cells, or dendritic cells. Decreased color intensity and continuity of PECAM-1 staining indicated loss of endothelial integrity in grafts preserved for longer than six hours. Intensity in VCAM-1 staining increased progressively in grafts preserved for more than six hours and was localized predominantly on the endothelium of elastic vessels. Endothelial cells, vascular smooth muscle cells, and monocytes expressed increasingly more tissue factor in grafts preserved for more than six hours, revealing enhanced intragraft procoagulant capacity. Furthermore, grafts with preservation times of more than six hours developed more severe vascular endothelial injury and worse tubular necrosis scores (P < or = 0.001) compared with grafts with shorter preservation times.


CONCLUSIONS
Because of the prominent vascular injury, strategies for endothelial protection should be attempted in grafts with long preservation times in clinical renal transplantation.
Dragun
D
D
Franz Volhard Clinic at the Max Delbrück Center for Molecular Medicine, Medical Faculty of the Charité, Humboldt University, Berlin, Germany.
Hoff
U
U
Park
J K
JK
Qun
Y
Y
Schneider
W
W
Luft
F C
FC
Haller
H
H
D000818:Animals; D015925:Cryopreservation; D004730:Endothelium, Vascular / Q000473:pathology*; D006085:Graft Survival; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D039041:Integrin alpha4beta1; D016023:Integrins / Q000032:analysis; D007668:Kidney; D016030:Kidney Transplantation / Q000276:immunology / Q000502:physiology*; D007684:Kidney Tubules / Q000473:pathology; D016169:Lymphocyte Function-Associated Antigen-1 / Q000032:analysis; D008297:Male; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000032:analysis; D051381:Rats; D016201:Receptors, Lymphocyte Homing / Q000032:analysis; D015427:Reperfusion Injury / Q000473:pathology*; D013925:Thromboplastin / Q000032:analysis; D013997:Time Factors; D019010:Vascular Cell Adhesion Molecule-1 / Q000032:analysis
D000949:Histocompatibility Antigens Class II; D039041:Integrin alpha4beta1; D016023:Integrins; D016169:Lymphocyte Function-Associated Antigen-1; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D016201:Receptors, Lymphocyte Homing; D019010:Vascular Cell Adhesion Molecule-1; D013925:Thromboplastin