Safety and Efficacy of Ex Vivo Donor Lung Adenoviral IL-10 Gene Therapy in a Large Animal Lung Transplant Survival Model.

Ex vivo normothermic lung perfusion (EVLP) is a novel platform and method developed to facilitate functional assessment and implementation of advanced therapies for donor lungs prior to transplantation. This study aimed to determine the safety and immunological and functional benefits of ex vivo adenoviral human interleukin-10 (AdhIL-10) gene delivery to prevent the development of primary graft dysfunction in a large animal survival model. Pig donor lungs were retrieved, preserved for 6 h at 4°C, and then randomly assigned to four groups: (1) AdhIL-10 gene therapy: 12 h EVLP + AdhIL-10 intra-bronchial delivery; (2) EVLP-control: 12 h EVLP; (3) Vector-control: 12 h EVLP + adenoviral vector intra-bronchial delivery; and (4) prolonged hypothermic preservation: additional 12 h of cold ischemia. The left lung was then transplanted and evaluated. The recipients were recovered and kept alive until day 7 post-transplant under standard triple immunosuppression. Plasma levels of hIL-10 were detected in the treatment group throughout the 7 days. Analysis of peripheral blood obtained after transplant showed no signs of hematological, renal, or hepatic toxicity in the AdhIL-10 group. The immediate post-transplant lung function was significantly better in the EVLP-control and AdhIL-10 groups. Gas exchange at day 7 was superior in allografts from the AdhIL-10 group, and the histologic inflammation score was significantly lower. Lymphocytes from AdhIL-10 group harvested from mediastinal lymph nodes at day 7 post-transplantation and co-cultured with donor lymphocytes showed significantly less interferon gamma production in an Enzyme-Linked ImmunoSpot assay when compared with non-treatment groups. It has been demonstrated in this preclinical large animal survival study that ex vivo treatment with AdhIL-10 is safe and improves post-transplant lung function over EVLP alone. Improved function and an immunological advantage in both the innate and adaptive immune responses have been demonstrated.

Extension of donor lung preservation with hypothermic storage after normothermic ex vivo lung perfusion.

BACKGROUND: Ex vivo lung perfusion (EVLP) allows normothermic evaluation and treatment of donor lungs not currently acceptable for transplant and improves organ use. Donor lungs undergo a period of cold preservation before (cold ischemic time [CIT]-1) and after (CIT-2) EVLP. We investigated the effect of an extended CIT-2 on lung function after transplantation. METHODS: Explanted pig lungs, preserved in low-potassium dextran flush (Perfadex) at 4°C for 10 hours, were subjected to 6 hours of EVLP. They were subsequently allocated to 2 groups: short CIT-2 (CIT-2 = 2 hours; n = 5), and long CIT-2 (CIT-2 = 10 hours; n = 5). In a control group (n = 6), explanted lungs were placed in cold static preservation for 24 hours without EVLP. After the total preservation period, the left lung was transplanted in all groups. RESULTS: After 4 hours of reperfusion, oxygenation function, acute lung injury score, inflammatory markers, and cell death pathway markers were similar between short and long CIT-2 groups. Both EVLP groups fared significantly better than the control group in oxygenation function (p < 0.05). CONCLUSIONS: The intervention of EVLP improved lung function after transplantation, and this was not affected by a prolonged cold static preservation time after EVLP. These results provide the basis for a practical prolonged lung preservation strategy using a combination of cold and warm preservation techniques, which may improve lung transplantation logistics and outcomes.