Acute Severe Hepatitis B Virus Infection in Previously Vaccinated Patient during Acalabrutinib Treatment.

We describe acute severe hepatitis B virus (HBV) infection with liver failure requiring transplantation in a patient in Poland treated with acalabrutinib. The patient was fully vaccinated against HBV and had adequate HBV antibody titers and no HBV exposure documented before therapy. Differential diagnoses for jaundice should consider HBV in patients receiving acalabrutunib.