Chen YL, et al. - Authors gauged the presence of hepatitis B virus (HBV) in the synovium and its clinical significance in rheumatoid arthritis (RA). They determined HBV in synovium by immunohistochemical staining for hepatitis B virus surface antigen and hepatitis B virus core antigen (HBcAg) and by nested PCR for the HBV S gene. Findings suggested that the presence of HBV in RA synovium demonstrated a probable involvement in the pathogenesis of local lesions and this may exacerbate the disease progression. In most disease activity indicators, there were smaller improvements from baseline mainly at month 12, and 1-year radiographic progression was experienced by a notably higher percentage of CHB patients.