New Immunotoxin Treatment Shows Promise Against Liver Fibrosis in Mice

Liver fibrosis, a condition marked by the buildup of scar tissue and collagen, remains difficult to treat. Current options are limited, with weight loss being the main approach for non-alcoholic fatty liver disease. Now, researchers at the University of California San Diego School of Medicine are testing a new method using immunotoxins to target the disease directly. Liver fibrosis often develops from chronic alcohol abuse, hepatitis, or fatty liver disease. Once scar tissue forms, the organ struggles to function properly. Early-stage liver transplants can cure the condition, but only a small number of patients qualify for the procedure. Existing treatments, such as corticosteroids for alcoholic liver disease, show limited success.

The new approach focuses on immunotoxins—molecules designed to kill specific cells. These toxins target mesothelin, a protein rarely found in healthy bodies but present in collagen-producing cells. In tests on mice with human liver cells, the treatment reduced these harmful cells by 60 to 100 percent. The findings were published in *Proceedings of the National Academy of Sciences* on July 12, 2021, under the DOI **10.1073/pnas.2101270118**.

The study suggests immunotoxins could offer a more effective way to treat liver fibrosis than current methods. By targeting collagen-producing cells, the approach may reduce scarring and improve liver function. Further research will determine whether the treatment works as well in humans as it did in mice.