The effects of brain death and ischemia on tolerance induction are organ-specific

Abstract

We have previously shown that 12 days of high-dose calcineurin inhibition induced tolerance in MHC inbred miniature swine receiving MHC-mismatched lung, kidney, or co-transplanted heart/kidney allografts. However, if lung grafts were procured from donation after brain death (DBD), and transplanted alone, they were rejected within 19-45 days. Here, we investigated whether donor brain death with or without allograft ischemia would also prevent tolerance induction in kidney or heart/kidney recipients. Four kidney recipients treated with 12 days of calcineurin inhibition received organs from donors rendered brain dead for 4 hours. Six heart/kidney recipients also treated with calcineurin inhibition received organs from donors rendered brain dead for 4 hours, 8 hours, or 4 hours with 4 additional hours of cold storage. In contrast to lung allograft recipients, all isolated kidney or heart/kidney recipients that received organs from DBD donors achieved long-term survival (>100 days) without histologic evidence of rejection. Proinflammatory cytokine gene expression was upregulated in lungs and hearts, but not kidney allografts, after brain death. These data suggest that the deleterious effects of brain death and ischemia on tolerance induction are organ-specific, which has implications for the application of tolerance to clinical transplantation.

Keywords: animal models: porcine; heart transplantation/cardiology; kidney transplantation/nephrology; lung transplantation/pulmonology; rejection; tolerance: experimental; translational research/science.

Figure 1

a) Serial cell-mediated lympholysis (CML) assays using responder cells from animal #21690. Pre-transplant anti-donor responses (blue) were lost by POD 62 but strong responses against 3^rd party antigen (Yorkshire PBMC) (red) persisted. b) Representative mixed-lymphocyte reaction (MLR) assays. In animal #21690 and animal #21420 pre-transplant anti-donor responses were lost by POD 30 (blue) but strong response against 3^rd party antigen (Yorkshire PBMC) (red) persisted. c) Serial CML assays using responder cells from animal #21736. Pre-transplant anti-donor responses were lost by POD35 (blue) but strong responses against 3^rd party antigen (Yorkshire PBMC) (red) persisted.

Figure 2

Donor brain death effects in recipients of heart/kidney versus lung allografts. Survival times of brain dead heart and kidney allograft recipients (solid line) are compared to the survival times of non-brain dead lung allograft recipients (dotted line) and brain dead lung allograft recipients (dashed line). The lung allograft data was published previously (3).

Figure 3

Change in tissue gene expression after brain death. qPCR was performed on RNA isolated from kidney (A), lung (B), and heart (C) tissue collected from animals before and 4 hours after induction of brain death. Fold change difference was calculated using the double delta Ct method, and all samples were normalized to GAPDH.