Acute liver failure (ALF) is the rapid loss of liver function due to severe injury to the liver cells, frequently leading to fatal outcomes over days or weeks, usually in previously healthy individuals. Liver transplantation (LT) is a life-saving treatment in approximately 30% of ALF patients who failed to respond to medical treatment. The cause of ALF is diverse including hepatotoxins, viral infection such as the hepatitis A, B, C, D, and E virus, hepatic ischemia, and autoimmune hepatitis. 1 Among them, the hepatitis E virus (HEV) is a positive-strand RNA virus with a 7.2 kb genome transmitted by the fecal-oral route. HEV is currently the most common cause of viral hepatitis globally, as reported by the World Health Organization (WHO): an estimated 20 million HEV infections, 3.3 million symptomatic cases, and 44 000 deaths in 2015. 2 However, there is a massive underestimation of the true burden of HEV infection due to a lack of knowledge among clinicians and the absence of a diagnostic gold standard. 3 HEV is a major cause of ALF in the Indian subcontinent and parts of Africa, but there are no case reports of ALF due to HEV infection in South Korea yet. De novo autoimmune hepatitis (AIH) rarely develops in LT recipients under immunosuppressive therapy who underwent LT due to non-AIH causes, but it shows nearly identical histological features to that of AIH. 4 Here, we report the first case of de novo AIH in a LT recipient after HEV-induced ALF, which suggests that HEV could have Abstract Acute hepatitis E virus (HEV) infection could lead to acute liver failure (ALF), which requires liver transplantation (LT). HEV infection could progress to chronic infection in an immunosuppressed host. De novo autoimmune hepatitis (AIH) is a rare occurrence of AIH during post-LT immunosuppressive therapy in patients who underwent LT due to not AIH but some other etiology. Here, we report the first case of ALF due to HEV infection, the recurrence of HEV after LT that responded to ribavirin therapy, and then the development of de novo AIH showing a complete response to glucocorticoid therapy but multiple relapses after steroid withdrawal. This peculiar case suggests that HEV could have a pathogenic role in the development of the de novo AIH; additionally, this case report could help clinicians make therapeutic decisions in the post-LT condition. K E Y W O R D S acute liver failure, autoimmune hepatitis, hepatitis E virus, liver transplantation How to cite this article: Choi JK, Ahn S, Cho JY, et al. A case of acute liver failure due to hepatitis E virus, liver transplantation, and development of de novo autoimmune hepatitis. Transpl Infect Dis. 2020;22:e13287. https://doi.

N,N-dimethylformamide (DMF), a widely used solvent in the chemical industry, is known to induce toxic hepatitis. However, there have been no reported cases of DMF-associated autoimmune hepatitis. A 31-year-old healthy man working at a glove factory since July 2015 had intermittently put his bare hands into a diluted DMF solution for his first 15 days at work. After 2 months, he felt nausea, fatigue, and hand cramping, and a jaundice followed. His laboratory findings showed positive autoantibodies and elevated immunoglobulin G (IgG), and his liver biopsy pathology was typical of autoimmune hepatitis (AIH). Prednisolone and azathioprine therapy began, and he recovered rapidly without adverse events. Though his liver chemistry was normalized, the IgG level remained persistently upper normal range. His 2nd liver biopsy performed in April 2019 showed mild portal activity, and he was well under a low dose immunosuppressive therapy up to April 2020. This case warns of the hazard of occupational exposure to DMF, and clinicians should be aware of DMF-related AIH for timely initiation of immunosuppressive therapy.