A case of possible drug-induced liver injury due to COVID-19 vaccine

The patient presented with nausea, appetite loss, and fatigue. She had received two doses of Pfizer/BioN-Tech BNT162b2 mRNA vaccine (COMIRNATYR) for coronavirus disease 2019 (COVID-19). Acute liver injury was noted 14 days after the first dose of the vaccine. Re-exposure through the second dose worsened the liver injury. After liver biopsy on the third day of admission, methylprednisolone (1000 mg) was administered. Liver histology showed acute hepatitis with diffuse lobular inflammation/necrosis and lymphocyte-dominant infiltra-tion in the portal areas. The patient was diagnosed with drug-induced liver injury due to the COVID-19 vaccine based on the Digestive Disease Week Japan 2004 (DDW-J) scale, which assesses the temporal relationship, liver biopsy, and laboratory findings. With improvements in the blood test parameters, prednisolone was gradually tapered and stopped. One month later, no biochemical signs of relapse were noted. To our knowledge, this is the first report describing liver injury after the administration of the Pfizer COVID-19 vaccine in Japan. Copyright © 2022 The Japan Society of Hepatology.