The overarching purpose of this study is to further understand the reasons for and clinical implications of persistent HBV infection in patients co-infected with HIV and HBV in the era of highly effective antiviral treatment against both viruses.

The French HIV-HBV Cohort is an observational, non-interventional study including 308 HIV-infected patients with chronic HBV infection (HBsAg-positive serology >6 months) in seven clinical centers. Patients were recruited in 2002-2003 and followed prospectively every three to twelve months, during two phases, until 2010-2011. Extensive information on a variety of HIV- and HBV-related parameters were collected during these study visits.

This particular study aims to extend follow-up of the French HIV-HBV Cohort using a different type of design. Patients who completed at least one study phase of the French HIV-HBV Cohort are selected for participation. Patients continuing follow-up at a participating clinical center are asked to undergo their routine clinical visit, during which time medical data from the years since last cohort visit until their routine visit are extracted. For those who died, information from the years since last cohort visit until death will be collected.

The primary objective for this cohort extension is to further understand the reasons for and clinical implications of persistent HBV infection in patients co-infected with HIV and HBV in the era of highly effective antiviral treatment against both viruses.

The following secondary objectives are as follows:

• To establish the extent of persistent viremia (PV) of HBV, quantified either in serum or within the hepatocyte
• To understand whether this persistence effects clinically-relevant serological outcomes (i.e. HBeAg and HBsAg seroclearance and seroconversion along with HBsAg quantification) after prolonged follow-up
• To quantify the evolution of liver fibrosis using non-invasive methods and, in a small subset of patients, liver biopsies, while investigating the virological and immunological factors associated with its progression and regression
• To describe the causes of liver-related and non-liver-related morbidity and mortality and the direct effect of persistent HBV DNA replication on these outcomes

Inclusion Criteria:

• HBsAg seropositivity for >6 months (at initial cohort inclusion)
• HIV-positive serology confirmed with Western blot (at initial cohort inclusion)
• Karnofsky score >70 (at initial cohort inclusion)
• Age ≥18 years old (at initial cohort inclusion)
• Completed follow-up in at least one previous study phase of the French HIV-HBV Cohort
• Obtained signed written informed consent

Exclusion Criteria:

• Refusal to participate
• Any severe physical, clinical or mental condition preventing participation

HIV-infected patients with chronic hepatitis B.

Data will only be made available upon official request, pending approval by the Scientific Committee.