Study of Anti-Viral Prophylaxis for HBsAg(+) or HBcAb(+)/HBsAb(-) Patients Starting Anti-TNFα

Inclusion Criteria: * Chronic hepatitis B, inactive HBsAg carriers or anti-HBc antibody positive patients with AST, ALT level equal or lower than 2x ULN * Patient who has systemic rheumatic disease for which anti-TNFα treatment indication has been approved by the KFDA; rheumatoid arthritis (RA, 1987 ACR criteria), ankylosing spondylitis (AS, modified New York criteria), psoriatic arthritis (PsA, modified ESSG criteria), and juvenile rheumatoid arthritis (JRA, 1977 ACR criteria). * Patient who is eligible to start anti-TNFα treatment (etanercept, infliximab, adalimumab, golimumab, and certolizumab pegol) due to treatment failure of other DMARDs against underlying RA, AS, PsA, or JRA. Patient who also fully understands that anti-TNFα agent expenses are not covered in this study. * Patient who is willing and able to comply with the study drug regimen and all other study requirements * Patient who is willing and able to provide a written informed consent to participate in the study Exclusion Criteria: * Patient who has liver cirrhosis or a history of hepatocellular carcinoma (HCC) or findings suggestive of HCC, such as suspicious foci or elevated serum alpha fetoprotein (AFP) * Patient who received interferon or other immunomodulatory treatment for HBV infection in the 12 months before screening for this study * Patient who has concomitant other chronic viral infection (HCV or HIV) * Patient who is pregnant or breastfeeding or willing to be pregnant * A history of chronic infe…