Abstract
Hepatitis B (HBV) in special populations within this article is considered as acute on chronic liver failure due to HBV, coinfection with Hepatitis C (HCV), Hepatitis D (HDV), or Human Immunodeficiency Virus (HIV), and HBV infection in patients who are in immunosuppressive states due to specific therapies and liver transplant recipients. Patients within these special populations are at higher risk of liver-related complications such as fibrosis, accelerated cirrhosis, acute on chronic liver failure, and/or development of hepatocellular carcinoma (HCC). Given their respective complex pathophysiology, specific treatment approaches are required for each population. With the introduction of effective antiviral HBV therapies over the past decade and the respective treatment options for the special population diseases, patient outcomes have seen improvement. With the advent of HCV direct antivirals, treatment of HBV-HCV coinfection has been more successful and consistently shown high rates of sustained virologic response. Treatment of HBV-HDV coinfection remains primarily as interferon-based, though new promising therapies have shown greater improvement in viral suppression. HBV-HIV coinfection has also shown promising results given overlapping mechanisms for treatment and specific regimens should be chosen to decrease risk of resistance. HBV reactivation in patients undergoing immunosuppressive therapies have been reported and guidelines recommend close monitoring and in certain cases, HBV antiviral therapy prophylaxis. With the effective HBV therapies, the perception of HBV as a contraindication for liver transplant has been diminishing and prolonged graft survival with effective antiviral therapies have shown promising outcomes.