It remains unclear why some individuals are able to clear HBV from their bodies while in others HBV is a persistent infection. We plan to investigate this process by collecting blood and analysing how the patient's white blood cells respond to different pieces of the HBV virus. We will use new tools that can precisely tell us which component of the immune response may be different in individuals who are chronically infected with HBV and also in individuals who are also infected with HIV.

The primary aims are therefore:

1. To characterize HBV-specific T cell responses in HBV chronic carriers, and identify novel immunogenic regions in both HLA-A2+ and non-HLA-A2+ individuals.
2. To determine the effect of HIV infection on HBV-specific T-cell responses

Inclusion Criteria:

There are two groups of patients in this study. Group A mono-infected with Hepatitis B, and those with co-infection HBV/HIV.

Group A inclusion criteria: (also split into 6 recruiting groups)

• Acute hepatitis B
• Chronic hepatitis B, HBV DNA+ve , normal ALT , HBeAg +ve
• Chronic hepatitis B, HBV DNA +ve , normal ALT, HBeAg -ve
• Chronic hepatitis , HBV DNA +ve, increased ALT, no HBV treatment B, HBeAg +ve
• Chronic hepatitis B, HBV DNA +ve , increased ALT, no HBV treatment B, HBeAg -ve
• Chronic hepatitis B, undergoing 'flare' of hepatitis

Group B inclusion criteria:

• To be HIV/HBV co-infected

All patients:

• To be over 18 years

Exclusion Criteria:

• Those who do not fit the inclusion criteria.

HIV and hepatitis B co-infection