Abstract:

BACKGROUND: Previous studies demonstrated that nitrogen cryopreservation can maintain cell biological activity and tissue construction integrality, however, there are few studies concerning immunological reaction of allogenic aortic valve transplantation.
OBJECTIVE: To observe the immune parameters changes following allogenic aortic valve transplantation.
METHODS: Hypothermic preserved allogenic aortic valve was transplanted into Wistar rats, and divided into groups. There was no intervention on the allogenic transplantation group; Ciclosporin A was injected into rats in the immune prevention group; in the control group, the aorta was cut down and re-anastomosed directly. The serum specimen was collected at 1, 2, 3, 4 and 5 weeks after transplantation. The MHCⅡ positive expression and percentage of CD4⁺ , CD8⁺ cells were measured by immunohistochemistry. The serum interleukin 2 and tumor necrosis factor α levels were measured by ELISA.   
RESULTS AND CONCLUSION: MHC positive could be seen at 1-4 weeks after transplantation, and the ratio of CD4⁺ , CD4⁺ /CD8⁺ was obviously increased, the serum interleukin 2 and tumor necrosis factor α levels were dramatically increased, and maintained a high level within 5 weeks after transplantation. Compared with the control group, there was significant difference (P < 0.05). Ciclosporin A exhibited an obvious inhibitory effect on intimal thickening, lymphocyte infiltration, MHCⅡ expression, T lymphocyte activation, as well as increased interleukin 2 and tumor necrosis factor α levels after allogenic transplantation (P < 0.05). The findings demonstrated that, there are obvious immunological rejections of allogenic aortic valve transplantation following hypothermic preservation, but ciclosporin A has notably inhibitory action.