A case of Atypical Occult Hepatitis B Infection (OBI) with HBsAg Negativity and High Anti-HBs Titer: Clinical implications

Abstract

A 72-year-old male patient was admitted presenting with upper abdominal distension and pain for one day. He had a 20-year history of hypertension and a 10-year history of hepatitis B, which he reported had been cured. Laboratory tests revealed a distinctive serological profile characterized by HBsAg negativity, anti-HBs positivity (714.2 mIU/ml), anti-HBe positivity, and anti-HBc positivity. However, HBV DNA was tested positive (5.962×10² IU/mL). The imaging studies revealed a heterogeneous space-occupying lesion in the left hepatic lobe. This case challenges the conventional perception that “a high anti-HBs titer is indicative of protective immunity and successful viral clearance”. The patient underwent resection of the lesion and received regular follow-up postoperatively.