S2804 Hepatitis B Seroconversion After Rituximab Treatment and Seroclearance After Tenofovir Treatment

Abstract

Introduction: Chronic hepatitis B affects more than 300 million people worldwide. The disease and its complications, especially hepatocellular carcinoma and cirrhosis, cause increased morbidity and mortality. We present the unique case of hepatitis B reactivation after rituximab and clearance after tenofovir treatment. Case Description/Methods: A 72-year-old African-American female with a history of type 2 diabetes mellitus, essential hypertension, and chronic hepatitis B (HBV) infection was diagnosed with neuromyelitis Optica (NMO) in February 2017. She was initiated started on rituximab infusions. Hepatitis B core antibody (anti-HBc) was positive in June 2018, with a negative hepatitis B surface antibody (anti-HBs) and hepatitis B surface antigen (HBsAg). Liver function tests (LFTs) at that time were unremarkable. In December 2019, her HBsAg turned positive. Her rituximab treatments were stopped and she was referred to the gastroenterology clinic. She was asymptomatic and denied intravenous drug use, tattoos, prior blood transfusions but did endorse multiple unprotected sexual encounters in the past. Repeat hepatitis tests in February 2020 revealed persistently positive HBsAg and anti-HBc, negative anti-HBs and HBeAg, and a viral DNA load of 387 IU/mL. LFTs were unremarkable. Ultrasound of the liver showed hepatic steatosis without cirrhosis. Her follow-up laboratory tests in May 2020 showed persistently positive HBsAg, negative anti-HBs and HBeAg, and a viral DNA load of 1048 IU/mL. She was diagnosed with hepatitis B reactivation after rituximab treatment and started on tenofovir 25 mg daily. Two months later, her tests showed a positive HBsAg but viral DNA decreased to undetectable levels (< 10 IU/mL). LFTs stayed within normal limits. Six months into treatment, her HBsAg and anti-HBc turned negative and viral DNA stayed undetectable. The HBsAg remained negative and viral DNA undetectable 9 months into treatment. She is currently doing well on routine clinic follow-ups. Discussion: It is important to monitor for reactivation of hepatitis B infection in people with a history of chronic infection, especially post-treatment with immunosuppressive drugs. Adequate treatment leading to HBV DNA and HBsAg seroclearance is rare but decreases morbidity.Table 1