Serum hepatitis B surface antigen monitoring in long-term lamivudine-treated hepatitis B virus patients

• Published in: Journal of viral hepatitis 2011-10, Vol.18 (10), p.e468-e474
• Main Authors: Gramenzi, A., Loggi, E., Micco, L., Cursaro, C., Fiorino, S., Galli, S., Gitto, S., Galli, C., Furlini, G., Bernardi, M., Andreone, P.
• Format: Article
• Language: English
• Subjects: Adult; antigen quantification; Antiviral Agents - administration & dosage; DNA, Viral - blood; Drug Monitoring - methods; Female; Hepatitis B Surface Antigens - blood; Hepatitis B virus; Hepatitis B, Chronic - drug therapy; Humans; Lamivudine - administration & dosage; Longitudinal Studies; Male; Middle Aged; nucleos(t)ide analogues; Predictive Value of Tests; Real-Time Polymerase Chain Reaction; Retrospective Studies; Serum - chemistry; treatment; Treatment Outcome; virological resistance
• ISSN: 1352-0504; 1365-2893
• DOI: 10.1111/j.1365-2893.2011.01473.x

Serum hepatitis B virus surface antigen (HBsAg) levels have been suggested to predict interferon response in chronic hepatitis B. A few data are available on the role of HBsAg measurement in nucleos(t)ide analogues (NA) treatment. We retrospectively investigated the relation between HBsAg changes and main treatment outcomes during long‐term lamivudine treatment in hepatitis e antigen (HBeAg)‐negative chronic hepatitis B. A total of 42 HBeAg‐negative patients were consecutively enrolled in an open‐label study on long‐term lamivudine monotherapy (150 mg/die). Serum HBsAg levels were quantified every 6 months by Architect assay (Abbott Diagnostics). HBV‐DNA was quantified quarterly by real‐time PCR (Roche Diagnostics). The median duration of lamivudine treatment was 66 months (20–153). One patient (2%) was a primary nonresponder, 35 (83%) developed virological breakthrough (VB) and the remaining six patients (14%) were classified as long‐term on‐treatment responders. During treatment, HBsAg levels decreased only in long‐term on‐treatment responders, while no changes were observed in resistant patients. Failure to achieve a decrease of 0.7 log10 IU/mL in serum HBsAg at month six of lamivudine had a positive predictive value of developing VB of 90% and a negative predictive value of 100%. These high predictive values were also maintained in the subgroup of patients negative for HBV‐DNA at month six. The results of this study with a small sample size suggest a role of on‐treatment HBsAg quantification in the management of lamivudine‐treated patients. If validated prospectively in a larger patient cohort, HBsAg measurements would be a useful adjunct to optimize antiviral therapy.