Treatment strategies for patients with hepatitis B virus infection coexisting with hepatitis C virus or metabolic dysfunction-associated steatotic liver disease.

Hepatitis B virus (HBV) remains a major cause of chronic liver diseases, especially in the Asia-Pacific region. In recent decades, coinfection with hepatitis C virus (HCV) and coexistence with metabolic dysfunction-associated steatotic liver disease (MASLD) have emerged as significant clinical concerns among HBV-infected patients. Although global HBV vaccination programs and curative therapies for HCV have led to a marked decline in HBV/HCV coinfection, MASLD is rapidly becoming the predominant comorbidity due to the global surge in metabolic risk factors. HBV/HCV coinfection typically results in more severe liver damage, with unique challenges in antiviral treatment and risk of HBV reactivation post-HCV clearance. In contrast, HBV/MASLD overlap demonstrates complex metabolic-viral interactions that may influence viral replication, hepatitis B surface antigen seroclearance, fibrosis progression, and risk of hepatocellular carcinoma. This review critically compares the epidemiology, clinical outcomes, and management strategies of HBV patients with concurrent HCV or MASLD, while addressing current research gaps and proposing directions for future investigations.