Inclusion Criteria:
- Written informed consent obtained from the subject.
- Subjects who the investigator believes that they can and will comply with the requirements of the protocol.
- A male or female between, and including, 18 and 65 years of age at study start.
- Evidence of chronic hepatitis B infection as per medical record.
- Female subjects of non-childbearing potential may be enrolled in the study.
- Female subjects of childbearing potential may be enrolled in the study, if the subject has practiced adequate contraception for 30 day prior to study start.
In addition to these general inclusion criteria, subjects should satisfy ALL specific criteria according to the specified group maximum 6 months prior to Visit 1 as per medical records:
Group A: Immune tolerant patients
- Viral load: > 2x107 IU/mL of HBV DNA
- HBeAg positive
- Normal levels of ALT according to lab range Group B: HBeAg positive chronic hepatitis B patients
- Viral load: > 2x104 IU/mL of HBV DNA
- HBeAg positive
- Increased levels of ALT and/or evidence of chronic hepatitis on liver biopsy Group C: Healthy carriers
- Viral load: not exceeding 2x103 IU/mL of HBV DNA
- HBeAg negative
- Normal levels of ALT measured at least twice, at least 3 months apart, during the last 6 months Group D: HBeAg negative chronic hepatitis B patients
- Viral load: > 2x103 IU/mL of HBV DNA
- HBeAg negative
- Increased levels of ALT and/or evidence of chronic hepatitis on liver biopsy
Exclusion Criteria:
- Any hepatitis B specific treatment prior to blood sampling at Visit 1.
- Any known clinically significant anaemia or any other condition within 7 days prior to study entry (Visit 1) as per medical records that would preclude the drawing of blood as described in the protocol.
- Receipt of live attenuated vaccines within 30 days preceding the blood sampling at Visit 1 and the administration of a pandemic influenza vaccine within 21 days preceding the blood sampling at Visit 1.
- Receipt of blood products within 120 days prior to study entry (Visit 1).
- Receipt of immunoglobulins within 120 days prior to study entry (Visit 1).
- Receipt of interferon within 120 days prior to study entry (Visit 1).
- Use of any investigational or non-registered product (drug or vaccine) within 30 days preceding study start, or planned use during the study period.
- Concurrently participating in another clinical study, at any time during the study period, in which the subject has been or will be exposed to an investigational or a non-investigational product (pharmaceutical product or device).
- History of immunosuppressive or immune-mediated disorders including autoimmune diseases, human immunodeficiency virus (HIV) infection and hepatitis C infection, based on medical history and physical examination (no laboratory testing required).
- Pregnant or lactating female.
- History of malignancy (unless there has been surgical excision followed by a sufficient observation period, of at least 5 years, to give a reasonable assurance of sustained cure and which, in the estimate of the investigator, is not likely to recur during the study period).
- Chronic administration (defined as more than 14 days) of immunosuppressants or other immune-modifying drugs (including chloroquine) within six months prior to the blood sampling at Visit 1 (for corticosteroids, this will mean prednisone ≥10 milligram/day (10 mg/day), or equivalent). Inhaled and topical steroids are allowed.
- History of type I or type II diabetes mellitus including cases controlled with diet alone (a subject with past gestational diabetes is eligible).
- History of major congenital defect.
- Subjects with a history of, or current, alcohol or substance abuse.