Peg-IFNα-2a Contributed to HBs Antigen Seroclearance in a Patient with Chronic Hepatitis B Administered Nucleic Acid Analogs: A Three-year Follow-up.

We treated a 51-year-old Japanese man with chronic hepatitis B (viral load 7.6 LC/mL, genotype C). HBV DNA and HBe antigen were undetectable during the administration of the nucleic acid analogs (NUCs) lamivudine and adefovir, although the concentration of HBs antigen (HBsAg) was 851.2 IU/mL. The HBsAg levels were reduced 150-fold when Peg-IFNα-2a was administered weekly for 48 weeks and did not increase during the rest period. Therefore, Peg-IFNα-2a was administered twice each week. During this time, HBsAg reached undetectable concentrations, and HBs antibody was detected and continued to be detectable during the three-year follow-up. These unprecedented findings suggest that IFN may contribute to the seroclearance of HBsAg in patients treated with NUCs.