Abstract
Ex situ normothermic machine perfusion (NMP) is rapidly emerging as a novel platform for testing therapeutics in human donor livers. Recently, perfusion of explanted patient livers was achieved, raising the possibility of using these diseased organs to increase the fidelity and resolution of drug testing and development. Here, we provide proof-of-principle for the feasibility of this approach in the context of gene therapy. We report the first successful administration of adeno-associated virus serotype 8 (AAV8) vector treatment in the explanted liver of a 34-year-old patient with mitochondrial neurogastrointestinal encephalomyopathy (MNGIE), using machine perfusion. MNGIE is caused by mutations in the thymidine phosphorylase (TYMP) gene, leading to nucleoside accumulation. The patient’s liver was split into anatomical left and right lobes and perfused using separate machine perfusion devices. Prior to treatment, nucleoside accumulation was observed in the perfusate of both lobes, recapitulating the cardinal feature of MNGIE. An AAV8 vector carrying the human TYMP gene was administered in the left lobe with the right serving as a control. AAV8 gene therapy resulted in successful vector uptake, with complete nucleoside clearance within 6 days of administration. Our results constitute the first demonstration of the efficacy of gene therapy for MNGIE in a human organ and provide proof-of-principle for using machine perfusion as a new strategy for disease modelling and testing novel therapeutics, e.g. gene therapy, in explanted livers.
•The liver explant of a patient with MNGIE was split and perfused independently for 7 days to test AAV gene therapy.•Nucleosides accumulated in both lobes (a key feature of MNGIE) but cleared in the treated lobe following gene therapy.•AAV gene therapy rescued TYMP deficiency in a human liver with MNGIE.•First demonstration of the safety and efficacy of AAV8 gene therapy in a human liver using machine perfusion.•Paradigm shift in perfusion: from donor organs to patient explants to test new treatments.