A Randomized Study to Assess the Loss of HbsAg After a 48-week Treatment Period With Pegylated Interferon Alpha 2a in Patients With Chronic Hepatitis B

Inclusion Criteria: * Positive Hbs Ag * Negative HbeAg * Plasma HBV DNA undetectable at pre-inclusion ever since 12 months * ALT less than or equal to 5 times the upper limit of normal * Non cirrhotic or Not Decompensated Cirrhosis (Child Pugh \<7) * Undetectable hepatocellular carcinoma in liver scan and / or alpha-fetoprotein rate \<50 ng / ml * Unchanged nucleoside (s) and / or nucleotide (s) treatment for at least three months (and not including telbivudine) * Negative pregnancy test for childbearing women * Signed informed consent * Use of contraception for childbearing women Exclusion Criteria: * Polymorphonuclear neutrophils \<1500/mm3 * Platelets \<70.000/mm3 * Co-infections with HIV, HCV and / or HDV * Prolonged excessive consumption of alcohol * Active intravenous drug addiction * Immunomodulators Treatment(eg interferons), ever since one year * Immunosuppressive treatments terminated ever since one year * Telbivudine treatment * Long course steroid treatment (more than 4 weeks) by oral way * History of severe epilepsy or current use of anticonvulsants * Severe heart disease (eg heart failure stage III or IV NYHA class, myocardial infarction less than 6 months, ventricular arrhythmia requiring treatment, unstable angina or other significant cardiovascular disease) * Chronic liver disease other than HBV-related (hemochromatosis, autoimmune hepatitis, metabolic liver disease, including Wilson's disease and a deficiency of alpha1-antitrypsin deficiency, alcoholic liver disease, exposure to toxins) * Presence or suspicion of cancer or a history of cancer (except basal cell carcinoma or in situ carcinoma) within 5 years preceding the randomization * Thyroid uncontrolled disease, abnormal TSH, elevated thyroid antibodies and clinical manifestations of thyroid dysfunction * History of autoimmune disease (inflammatory digestive, idiopathic thrombocytopenic purpura, lupus erythematosus, autoimmune hemolytic anemia, scleroderma, severe psoriasis, rheumatoid arthritis ....) Or presence of autoantibodies at a significant rate * Renal impairment (creatinine clearance \<50 ml / min using the Cockroft formula), renal transplantation, hemodialysis * Hypersensitivity to the active substance, interferon alpha or any component * History of depression or psychiatric disorders and uncontrolled depression or uncontrolled psychiatric disorders * Pregnancy or breastfeeding, or wish of pregnancy during the study period. * Patients under legal protection or unable to express their consent