Clin Mol Hepatol.  2016 Sep;22(3):382-389. 10.3350/cmh.2016.0047.

Hepatitis B surface antigen titer is a good indicator of durable viral response after entecavir off-treatment for chronic hepatitis B

• Lee HA
• Seo YS
• Park SW
• Park SJ
• Kim TH
• Suh SJ
• Jung YK
• Kim JH
• An H
• Yim HJ
• Yeon JE
• Byun KS
• Um SH

• KMID: 2373139
• DOI: http://doi.org/10.3350/cmh.2016.0047

Abstract

BACKGROUND/AIMS
Clear indicators for stopping antiviral therapy in chronic hepatitis B (CHB) patients are not yet available. Since the level of hepatitis B surface antigen (HBsAg) is correlated with covalently closed circular DNA, the HBsAg titer might be a good indicator of the off-treatment response. This study aimed to determine the relationship between the HBsAg titer and the entecavir (ETV) off-treatment response.
METHODS
This study analyzed 44 consecutive CHB patients (age, 44.6±11.4 years, mean±SD; men, 63.6%; positive hepatitis B envelope antigen (HBeAg) at baseline, 56.8%; HBV DNA level, 6.8±1.3 log₁₀ IU/mL) treated with ETV for a sufficient duration and in whom treatment was discontinued after HBsAg levels were measured. A virological relapse was defined as an increase in serum HBV DNA level of >2000 IU/mL, and a clinical relapse was defined as a virological relapse with a biochemical flare, defined as an increase in the serum alanine aminotransferase level of >2 × upper limit of normal.
RESULTS
After stopping ETV, virological relapse and clinical relapse were observed in 32 and 24 patients, respectively, during 20.8±19.9 months of follow-up. The cumulative incidence rates of virological relapse were 36.2% and 66.2%, respectively, at 6 and 12 months, and those of clinical relapse were 14.3% and 42.3%. The off-treatment HBsAg level was an independent factor associated with clinical relapse (hazard ratio, 2.251; 95% confidence interval, 1.076-4.706; P=0.031). When patients were grouped according to off-treatment HBsAg levels, clinical relapse did not occur in patients with an off-treatment HBsAg level of ≤2 log10 IU/mL (n=5), while the incidence rates of clinical relapse at 12 months after off-treatment were 28.4% and 55.7% in patients with off-treatment HBsAg levels of >2 and ≤3 log₁₀ IU/mL (n=11) and >3 log₁₀ IU/mL (n=28), respectively.
CONCLUSION
The off-treatment HBsAg level is closely related to clinical relapse after treatment cessation. A serum HBsAg level of <2 log₁₀ IU/mL is an excellent predictor of a sustained off-treatment response in CHB patients who have received ETV for a sufficient duration.

Keyword

Hepatitis B virus; Hepatitis B surface antigen; Relapse; Off-treatment

MeSH Terms

Adult
Alanine Transaminase/blood
Antiviral Agents/*therapeutic use
DNA, Viral/blood
Female
Follow-Up Studies
Guanine/*analogs & derivatives/therapeutic use
Hepatitis B Surface Antigens/blood
Hepatitis B virus/genetics/isolation & purification
Hepatitis B, Chronic/*drug therapy
Humans
Male
Middle Aged
Multivariate Analysis
Polymerase Chain Reaction
Recurrence
Treatment Outcome
Alanine Transaminase
Antiviral Agents
DNA, Viral
Guanine
Hepatitis B Surface Antigens