Effect of Cold-Preservation on the Vessels of Vascularized Composite Allografts in Rats

Abstract

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. This work was granted by the Fundación Investigación IdiPaz, Madrid.J.B. presented this work and won the Residents Award of the Spanish Society of Plastic & Reconstructive Surgery, during the National Meeting held in Tenerife (Spain) in 2014.