Finding fibroblast growth factor 19 during cholestasis: Does x mark the spot?/ Reply

Brandl et al reply to Drs de Haan and van Golen's comments on their recent study of bile acid metabolism and FCF19 in patients with alcohol use disorder and alcoholic hepatitis. Under physiological conditions, FGF19 is primarily expressed in intestinal epithelial cells of the terminal ileum and reaches the liver via the portal circulation to regulate bile acid synthesis in hepatocytes. As elaborated by Drs de Haan and van Colen, although induction of hepatic FGF19 likely increases serum FGF19 in patients with alcoholic hepatitis, other sites, such as the terminal ileum as the primary source for FGF19, might contribute to this systemic increase as well.