Challenges and opportunities for hepatitis B cure in the setting of HIV--hepatitis B virus co-infection

To examine issues specific to HIV--HBV co-infection that are relevant to the search for and achieving hepatitis B cure in this the setting RECENT FINDINGS: In HIV--HBV co-infection, high rates of hepatitis B surface antigen (HBsAg) loss early after initiation of HBV-active antiretroviral therapy (ART) have previously been reported. Between 2012 and 2016, HBsAg loss from 2.8 to 23% was reported in numerous studies, including those already on suppressive HBV-active ART. Data published in 2018-2019 show that these rates have remained fairly stable (3.0-13.9%). However, it appears that higher HBsAg loss on starting HBV-active ART in co-infection falls within a few years to levels similar to that observed in long-term treated HBV mono-infection. Immune reconstitution and CD4+ T-cell recovery are likely to play a role in high HBsAg loss rates seen in early treated co-infection, although the mechanisms driving this are yet to be fully elucidated.

High rates of HBsAg loss early after HBV-active ART initiation is unique to HIV--HBV co-infection, making it the ideal setting to investigate underlying mechanisms of HBV loss and develop new HBV cure strategies. This phenomenon could be used to enhance HBsAg loss with new therapeutic approaches currently being investigated; however, this is obstructed by excluding co-infection from such studies.