Management of hepatitis B virus coinfection in people with human immunodeficiency virus: Current guidelines, challenges, and future perspectives in Japan.

Hepatitis B virus (HBV) coinfection remains a clinically relevant challenge in people with human immunodeficiency virus (PWH) because of shared transmission routes. Moreover, the recent development of novel antiretroviral therapy (ART) without anti-HBV potency highlights the importance of managing HBV coinfection in this population. This review aims to discuss the epidemiology of HBV coinfection, current recommendations, unresolved challenges, and future perspectives for HBV management in PWH in Japan based on published literature. The prevalence of HBV coinfection among PWH remains substantial in East Asia (e.g., 6.4% in Japan; 13.7% in China). In Japan, the persisting burden of HBV coinfection in PWH can be attributed to the late implementation of universal infant HBV vaccination. Major HIV management guidelines recommend HBV testing for PWH, vaccination for those without HBV immunity, and the use of tenofovir-based ART for those with HBV coinfection. Currently, several challenges exist in the management of HBV coinfection in PWH. The serological patterns and their clinical interpretations are highly complex, and some PWH have the risk of HBV reactivation after switching to ART with low or no anti-HBV activity. PWH without HBV immunity should receive HBV vaccines, but their low seroprotection rates often pose a challenge to the use of novel ART with no HBV activity, such as long-acting injections. New vaccines and treatment options under development, including toll-like receptor agonists and gene-silencing oligonucleotide agents, are warranted to improve the management of HBV coinfection in PWH.