Introduction: We evaluated the effect of cold ischemia on the development of chronic rejection in vascularized composite allotransplantation.
Methods: Thirty rat hindlimbs were transplanted from LBN to WL rats and divided into two experimental groups: immediate transplantation and transplantation after 7 hours of cold preservation ischemia. The animals received daily low-dose immunosuppression with cyclosporine A for 2 months. Intimal proliferation, arterial permeability rate, leukocyte infiltration and tissue fibrosis were assessed. To elucidate the mechanism of rejection immunohistochemical and RT-PCR cytokine analysis (Roche LightCycler) were performed.
Results: Significant differences were found in the intimal proliferation and arterial permeability rate between the two groups (p = 0.004). The arterial permeability rate worsened in the most distal and small vessels (p = 0.047). The numbers of CD3+, CD8+, CD20+, and CD68+ were also statistically higher in the cold ischemia group (p < 0.05, all levels). A trend toward significance was observed with C4d deposition (p = 0.059). No differences were found in the RNA of cytokines.
Conclusions: An association between cold ischemia and chronic rejection was observed in rat hindlimb allografts in a sub-optimal immunosuppression setting. Chronic rejection intensity and distal progression were significantly related with cold ischemia. The leukocyte infiltrates were a rejection marker, but their exact implication in monitoring and their relation with cold ischemia are yet to be clarified.