title: Six-year follow-up of hepatitis B surface antigen concentrations in tenofovir disoproxil fumarate treated HIV-HBV-coinfected patients.
abstract: BACKGROUND
  Quantitative measurement of hepatitis B surface antigen (HBsAg) has been proposed as a surrogate marker of treatment efficacy when HBV DNA load becomes undetectable. Our main objective was to study the kinetics of HBsAg level in HIV-HBV-coinfected patients with undetectable HBV DNA load under treatment containing tenofovir disoproxil fumarate (TDF).
  
  
  METHODS
  A retrospective analysis was performed on frozen serum samples of 33 HIV-HBV-coinfected patients who were treated with TDF and had undetectable HBV DNA for ≥1 year. Baseline and serial follow-up samples were assayed for HBsAg levels.
  
  
  RESULTS
  The characteristics of the patients at TDF initiation were median age 43.6 years, median HBV DNA load 2 log(10) IU/ml and median HBsAg concentration 3.4 log(10) IU/ml. Ten patients were positive for hepatitis B e antigen. Baseline median HBsAg concentration, defined 1 year after HBV DNA became undetectable, was 3.1 log(10) IU/ml. Overall, from years 1 to 6 and a median duration of TDF treatment of 2.6 years, the median HBsAg concentration decreased slowly. Notably, only 13 (39%) patients presented a constant decrease of HBsAg concentration, whereas the remaining had fluctuating or increasing HBsAg concentrations. The slope was not influenced by HBeAg status, HIV infection duration and CD4(+) T-cell count at baseline or at nadir.
  
  
  CONCLUSIONS
  Despite control of HBV DNA replication under efficient TDF treatment, HBsAg levels persistently decreased in only 39% of HIV-HBV-coinfected patients. Larger follow-up studies are needed to determine whether HBsAg concentration monitoring under analogue treatment can be used as a reliable marker for HBV clearance.
authors: Virology Laboratory, Hôpital Pitié-Salpêtrière, Assistance Publique, Paris, France. vincent.thibault@psl.aphp.fr
authors: Vincent
authors: V
authors: Thibault
authors: Hind
authors: H
authors: Stitou
authors: Nathalie
authors: N
authors: Desire
authors: Marc-Antoine
authors: MA
authors: Valantin
authors: Roland
authors: R
authors: Tubiana
authors: Christine
authors: C
authors: Katlama
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D005500:Follow-Up Studies; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D015497:HIV-1 / Q000187:drug effects; D006514:Hepatitis B Surface Antigens / Q000097:blood*; D006515:Hepatitis B virus / Q000187:drug effects; D019694:Hepatitis B, Chronic / Q000150:complications / Q000188:drug therapy / Q000821:virology; D006801:Humans; D008875:Middle Aged; D063065:Organophosphonates / Q000627:therapeutic use*; D018894:Reverse Transcriptase Inhibitors / Q000627:therapeutic use*; D000068698:Tenofovir; D055815:Young Adult
chemical_list: D019380:Anti-HIV Agents; D006514:Hepatitis B Surface Antigens; D063065:Organophosphonates; D018894:Reverse Transcriptase Inhibitors; D000068698:Tenofovir; D000225:Adenine