Wang, Yichen

Ex vivo liver perfusion (EVLP) sustains human or large animal livers outside the body under near-physiological conditions, enabling functional monitoring for lactate clearance, bile production, and oxygen consumption and allowing targeted therapeutic interventions. Originally developed to optimize donor grafts for transplantation, EVLP has evolved into a powerful translational research platform bridging preclinical discovery and early clinical translation. This review discusses EVLP as a platform for gene therapy, immunotherapy, pharmacology, and personalized medicine, with particular emphasis on gene- and immune-based interventions as mechanistically mature exemplars. We consolidate advances in pharmacological testing and toxicity modeling, viral and non-viral gene delivery, genome engineering, and immunomodulation using perfused livers. We further describe emerging applications, including autologous EVLP pathways for organ-confined therapy, ex vivo liver surgery, and bioengineering strategies such as biliary organoid repair, RNA interference, and mitochondrial transfer. We highlight how these applications align with a paradigm shift in biomedical research, including the NIH’s recent initiative to prioritize human-based experimental models over animal-only studies. By leveraging transplant-declined or surgically resected organs that would otherwise be unused, ex vivo perfusion bridges the gap between pre-clinical testing and clinical practice, enabling real-time evaluation of interventions in functional human tissue. We discuss both the scientific opportunities afforded by EVLP and the technical, biosafety, and ethical challenges that must be addressed to enable responsible clinical translation.

Abstract Background: Metabolic-associated fatty liver disease (MAFLD) is a common liver disease and may become the leading cause of severe liver disease in the future. The Global Burden of Disease (GBD) study assesses MAFLD’s impact in countries and regions worldwide, providing insights into its prevalence. Methods: Prevalence data for MAFLD from 1990 to 2021 by country and region in all sex and age groups were collected from the Global Health Data Exchange. The categorization of countries and geographic areas by development was performed using the Sociodemographic Index (SDI). Results: Between 1990 and 2021, the global crude prevalence rate of MAFLD increased from 10.6% to 16.1% (beta-coefficient: 0.2%, 95% confidence interval [CI]: 0.2–0.2%, P <0.001), and the age-standardized prevalence rate was increased from 12.1% to 15.0% (beta-coefficient: 0.1%, 95% CI: 0.1–0.1%, P <0.001). In 2021, MAFLD was estimated to have affected 1.3 billion people worldwide. Significant uptrends were observed in all regions, super regions, and SDI categories. The fastest increase from 1990 to 2021 and the highest prevalence rate in 2021 were experienced by countries and territories with high–middle and middle SDI. An increase in the prevalence of MAFLD from 1990 to 2021 was demonstrated in all but six countries. Conclusions: In 2021, the number of patients affected by MAFLD was doubled compared to 1990, and the prevalence rate increased by over 50%. The burden of MAFLD, as measured by prevalence, was more prominent in countries and territories with middle SDI and in those located in North African and Middle Eastern, possibly due to changes in lifestyle in these areas over the past 30 years.