Real-world Prevalence of Hepatitis B Reactivation in Patients With Resolved Hepatitis B Receiving Rituximab and Non-rituximab-based Immunosuppressive Therapy Without Chemoprophylaxis.

BACKGROUND

Hepatitis B virus reactivation (HBVr) can occur in patients with resolved hepatitis B virus (HBV) infection receiving immunosuppressive therapy. The class of immunosuppression influences HBV reactivation (HBVr) risk, with B-cell depleting agents such as Rituximab conferring a higher risk. The presence of hepatitis B surface antibodies (HBsAb) may be protective against HBVr.

OBJECTIVE

To compare the rates of HBVr amongst individuals with resolved HBV infection receiving rituximab and non-rituximab immunosuppressive therapy, without chemoprophylaxis. Our secondary objective was to explore the role of HBsAb in risk stratification for HBVr.

METHODS

We retrospectively collected the data of patients with resolved HBV infection receiving immunosuppressants between 2014 and 2022. HBVr rates amongst patients receiving rituximab and non-rituximab therapy were compared. Logistic regression analysis was performed to identify risk factors for HBVr.

RESULTS

148 patients with resolved HBV infection did not receive chemoprophylaxis. Of the 20 (13.5%) patients who developed HBVr, none developed HBV flare. 42 of the 148 (28.3%) patients received rituximab-based therapy. Patients who received rituximab had a higher risk of HBVr, 12(28.6%) vs 8(7.5%),  = 0.001. This was confirmed on multivariable analysis (OR 4.19 [C.I. 1.47-11.9],  = 0.007). HBsAb titres of above 100 mIU/ml were protective against HBVr (OR 0.04 [CI 0.001-0.84],  = 0.039) in the rituximab exposed cohort, but not in the non-rituximab exposed cohort.

CONCLUSION

The risk of HBVr was higher in patients receiving rituximab; however, no patient developed HBV flare. In patients with resolved HBV infection, the presence of HBsAb titres above 100 mIU/ml may confer additional protection against HBVr and can be used as part of risk stratification for HBVr. In such patients, close surveillance with on-demand therapy instead of chemoprophylaxis may be considered.