The topic of Hepatitis B virus (HBV) reactivation has been discussed on this blog before (see link below). Another excellent review on this topic (R Lomba, TJ Liang. Gastroenterol 2017; 152: 1297-1309) has been published. The authors examine the course and mechanisms of HBV reactivation. They divide the risk of reactivation into three groups: high, moderate and low risk and proposed management.
High risk groups, which have >10% risk of reactivation) include the following
- B-cell-depleting agents including rituximab, ofatumumab, alemtuumab, and ibritumumab
- High-dose corticosteroids (>20 mg/day in adults)
- Antracyclines including doxorubicin
- Potent TNF-α inhibitors: infliximab, adalimummab, certolizumab, and golimumab
- Local therapy ofr HCC including TACE (transarterial chemoembolization)
Moderate groups (1-10% reactivation) include cytokine-based Rx (eg. abatacept, ustekinumab, natalizumab, vedolizumab), cyclosporine, systemic chemotherapy, moderate corticosteroid dosing
Low risk groups (<1% reactivation) include thiopurines (azathioprine, 6-mercaptopurine), and methotrexate as well as short-term low-dose corticosteroids.
- For HBV screening, the authors recommend HBsAg and anti-HBc testing
- Prophylactic therapy with potent oral anti-HBV therapies are recommended for those at moderate or high risk of reactivation. In those at low risk, the options include prophylactic treatment or watchful monitoring.
- A more detailed algorithm is provided in Figure 3. In those with HBsAg positivity, if HBV DNA is less than 2000 U/mL, this algorithm suggests monitoring labs (HBsAg, ALT, HBV DNA every 3 months)
Mechanisms of HBV reactivation are discussed. For example, with TNF-α inhibitors “can activate a unique host antiviral pathway, the APOBEC (apolipoprotein B mRNA editing enzyme, catlytic polypeptide-like) proteins, that cause the degradation of cccDNA in HBV-infected cells. Thus, blocking this endogenous antiviral pathway may lead to a higher HBV replication state and HBV reactivation.”
My take: In pediatric gastroenterology, we do not see a lot of HBV reactivation. Nevertheless, we do use many of the medications which can trigger HBV reactivation and need to keep these recommendations in mind.
Related blog post: What HBV Testing is Needed Before TNF Inhibitor Therapy