P1931 - The Return of HBV

Arjan Ahluwalia, MD, Reema Vaze, MD, Henry Lam, DO, She-Yan Wong, MD
Lehigh Valley Health Network, Allentown, PA

Introduction: Chronic hepatitis B (HBV) is a globally prevalent viral infection that can lead to a range of clinical presentations in the acute and chronic phase. HBV reactivation in immunocompromised patients is of particular importance as these patients are often asymptomatic but if left untreated, it can lead to severe liver injury and even death. We present a case of HBV reactivation with a negative hepatitis B surface antigen.

Case Description/Methods: A 67-year-old Caucasian male with past medical history of chronic lymphocytic leukemia (CLL) on rituximab, rheumatoid arthritis on methotrexate and mitral valve replacement on coumadin presented with painless jaundice. Labs were notable for total bilirubin (TB) of 14.2 mg/dL, AST 300 U/L, ALT 201 U/L and ALP 135 U/L, platelets 121, and INR 2.3. Exam was significant for jaundice, intact mental status, and no asterixis. The patient last received a dose of rituximab 1 month prior and had been on this for the past 4 years. Initially, the patient’s methotrexate was stopped without improvement. Workup included CT abdomen that showed normal liver and bile ducts with noted splenomegaly. Hepatitis panel revealed a negative hepatitis B surface antigen (HBsAg), but positive hepatitis B core IgM antibody (anti-HBc) and surface antibody. Hepatitis Be antigen (HBeAG) and hepatitis B e-antibody (anti-HBe) were both positive and the HBV viral load was 6950 IU. Given these findings, he was diagnosed with acute HBV likely from reactivation. He was started on Vemlidy (tenofovir alafenamide) 25 mg daily and after 3 months of treatment, liver tests were almost normal.

Discussion: Our case describes HBV reactivation in the setting of immunosuppression with a negative HBsAg. HBV reactivation is a known risk with HBV carriers treated with rituximab. The risk is highest for patients with positive HBsAg and moderate for those with positive anti-HBc. It is recommended that these patients are started on HBV prophylaxis. This case was interesting in that HBV reactivation often leads to seroconversion with a positive HBsAg. Negative HBsAg reactivation is rare with a reported rate of 0.3-9%. Studies suggest that this arises due to mutations in the immunodominant region of the HBsAg rendering it undetectable by commercial assays. These mutations are driven by selection pressures in response to the body’s immune response, vaccinations, or antiviral therapies. Reactivation of HBV should be kept on the differential especially in immunosuppressed patients despite negative serologies.


Disclosures:


Arjan Ahluwalia, MD, Reema Vaze, MD, Henry Lam, DO, She-Yan Wong, MD. P1931 - The Return of HBV, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.