Abstract:Background/Aims: We evaluated the rate of seroclearance of the hepatitis B surface antigen (HBsAg) and its clinical significance in patients with chronic hepatitis delta virus (HDV). Methods: Antibody to HDV was tested in HBsAg-positive subjects admitted to our Hospital from 1991 to 1995. In 1997, a biochemical and virologic study was performed in the surviving anti-HD-positive patients who had not undergone transplantation. As a control, a cohort of 106 HBsAg-positive, anti-HD-negative patients was studied. Results: One hundred and forty-one subjects were originally positive for anti-HD. After 4 years of follow-up, six of the 60 patients who underwent re-evaluation (10%) had cleared the HBsAg: three of the six patients had minimal changes at the initial liver histology and normal ALT, whereas in the remaining three patients with chronic active hepatitis ALT normalized during the observation. Anti-HD persisted in five of the six patients. Only one patient had raised anti-HBs. In contrast, three of 106 HBsAg carriers without HDV infection (2.8%) cleared the HBsAg within the same time and seroconverted to anti-HBs (p=0.002). Conclusion: HBsAg clearance is increased over the years in HDV patients compared to ordinary HBsAg carriers, and is often associated with improvement of HDV disease without seroconversion to anti-HBs.