LAUSR

The 2020 Nobel Prize in Physiology or Medicine was awarded to Harvey Alter, Michael Houghton, and Charles Rice for the discovery of the Hepatitis C Virus (HCV), the causative agent of hepatitis C. WHO estimates that, worldwide, 71 million people are currently living with chronic HCV infections which, if left untreated, can lead to cirrhosis and hepatocellular carcinoma, both of which can cause liver failure. At this advanced stage, the best treatment is liver transplantation. Globally, the number of patients in need of new organs vastly outnumbers successful transplantation operations. As of September, 2020, the US Health Resources and Services Administration stated that 109 000 US patients needed an organ donation (with livers being the second most required organ after kidneys). However, only 40 000 successful transplants were done in the USA in 2019. A similar story is seen worldwide. One way to address this concern is to increase the number of potential donors. In May, 2020, England altered its rules on organ procurement; from this date, all adults in the country are considered to have agreed to become donors upon death unless they opt out. Similar policies are present in other countries such as Israel, Chile, and Spain (who have had the policy since 1979). Increasing the number of potential donors is unlikely to solve the problem entirely, as not all donated organs are suitable for transplant and not all transplantation procedures are successful. A quartet of manuscripts published in the recent October Issue of EBioMedicine highlight research aimed at improving transplantation efficiency. Organs accrue damage throughout an individual’s life, potentially preventing transplantation. One of the most important metrics of liver health is the proportion of hepatocytes harbouring large fat vacuoles, known as steatosis. Fattier livers are more likely to undergo dysfunction if transplanted. Manuela Cesaretti (Beaujon Hospital, Clichy, France), writing in Liver Transplantation in 2019, stressed the need for reliable tools to measure steatosis. Work led by Lulu Sun (Washington University School of Medicine, MO, USA) in our October issue reported on a deep learning algorithm (DLA) that calculates steatosis from images of frozen liver biopsies. The DLA estimates were more accurate than those of the onsite pathologist using the same slides. Improving steatosis estimation would reduce rejection of healthy livers and prevent unhealthy livers reaching patients. Suitable organs require maintenance before transplantation. Organs donated after circulatory death are affected by ischemia, which causes a build-up of succinate. Succinate, in turn, releases reduced flavin mononucleotide (FMH2) from mitochondria. Upon