Universal hepatitis B virus (HBV) vaccination has been applied for years in most countries, but HBV infection remains an unresolved public health problem worldwide, with over one-third of the world’s population infected during their lifetime and approximately 248 million hepatitis B surface antigen (HBsAg) chronic carriers. HBV infection may reactivate with symptomatic and sometimes life-threatening clinical manifestations due to a reduction in the immune response of various origins, due to chemotherapy or immunosuppressive therapy, treatments increasingly practiced worldwide. SARS-CoV-2 and its COVID-19 associated disease have introduced new chances for HBV reactivation due to the use of dexamethasone and tocilizumab to counteract the cytokine storm. This could and should be prevented by accurate screening of HBV serologic markers and adequate pharmacologic prophylaxis. This article describes the case of a patient with COVID-19 who developed HBV reactivation and died of liver failure and analyzes published data on this setting to provide useful information to physicians who manage these patients during the SARS-CoV-2 pandemic.

Reactivation of overt or occult HBV infection (HBVr) is a well-known, potentially life-threatening event which can occur during the course of immunosuppressive treatments. Although it has been described mainly in subjects receiving therapy for oncological or hematological diseases, the increasing use of immunosuppressant agents in non-oncological patients observed in recent years has raised concerns about the risk of reactivation in several other settings. However, few data can be found in the literature on the occurrence of HBVr in these populations, and few clear recommendations on its management have been defined. The present paper was written to provide an overview of the risk of HBV reactivation in non-neoplastic patients treated with immunosuppressive drugs, particularly for rheumatological, gastrointestinal, dermatological and neurological diseases, and for COVID-19 patients receiving immunomodulating agents; and to discuss the potential strategies for prevention and treatment of HBVr in these settings.