The decrease of HBsAg during nucleos(t)ide analogues (NUC) therapy in Bulgarian patients

Abstract

Serum surface antigen of the hepatitis B virus (HBsAg) level has been recently introduced and studied during the last years as a simple and non-invasive serum surrogate marker for covalently closed circular DNA (cccDNA). The aim of the present study was to evaluate the serum HBsAg levels in Bulgarian patients during the first 12 months of therapy with nucleoside/nucleotide analogues (NUC). Twenty patients with chronic hepatitis B (CHB) infection were studied. Initially, 9 out of the 20 subjects were Hepatitis B ‘e’ antigen (HBeAg)-positive and 11 were HBeAg-negative. Serum hepatitis B virus DNA (HBV DNA), as well as serum HBsAg levels were measured prior therapy and after 3 and 12 months of treatment. The baseline HBsAg levels in HBeAg-positive patients were more than three times higher, compared to HBeAg-negative subjects. We found an initial slight increase of HBsAg in 2/9 HBeAg-positive patients and in 3/11 HBeAg-negative subjects. A positive correlation was found between baseline HBsAg and HBV DNA. A rapid decline of HBsAg levels was observed in one-third of the HBeAg-positive patients at the 12th month of treatment. In the HBeAg-negative patients, HBsAg levels remained relatively unchanged. Measurement of HBsAg levels during NUC therapy is not used routinely. After achieving a persistently undetectable serum HBV DNA and normal aminotransferase levels, HBsAg level remains an important surrogate marker for the course of the liver disease. The HBsAg levels, together with HBV DNA, may provide essential additional information and may help to define and evaluate the upcoming new therapeutic strategies.