Approach to HBsAg-Positive Patients

Author: H. Nina Kim, MD, MSc

Last updated: March 21, 2013

A 24-year-old Asian man presents for evaluation of a positive blood test for hepatitis B surface antigen (HBsAg), detected when he went to donate blood during a college blood drive. Further tests show the patient has normal hepatic transaminase levels and a normal bilirubin. The patient was born in China and immigrated to the United States with his family when he was 15 years old. He is otherwise healthy and takes no medications. He has recently begun having sex with his girlfriend of 3 months. He has previously had one other sex partner.

Which of the following describes the most appropriate initial laboratory evaluation of this patient?

A The next appropriate blood test is a hepatitis B core antibody (anti-HBc), which alone can determine if the patient has acute hepatitis B infection.
B The most appropriate blood test is a hepatitis B e antigen (HBeAg), which alone can determine if the patient is an inactive carrier of hepatitis B or if he is actively infected.
C No further blood work is necessary. The finding of positive HBsAg alone is enough to define the patient as a chronic hepatitis B carrier, and he should be screened for hepatocellular carcinoma with a serum alpha-fetoprotein measurement and abdominal ultrasound.
D Appropriate laboratory studies should include a complete hepatitis B serologic evaluation, a serum HBV DNA level, and biochemical markers related to hepatic inflammation and function.