Impact of the introduction of an hbv testing and treating policy in patients being treated with immunosuppression

Introduction

Individuals with current or previous hepatitis B virus infection (HBV) can experience reactivation of hepatitis B virus when treated with immunosuppressants. Therefore, international guidelines recommend HBV screening prior to initiation of immunosuppression. We introduced n HBV testing and treatment guideline in our Trust for patients treated with immunosuppression in December 2013. The aim of this work was to assess the impact of testing on the HBV diagnosis and subsequent initiation of anti-viral therapy for those with high risk of HBV reactivation.

Methods

A retrospective review of our Trust laboratory database was performed between 2010 and 2022 to identify patients being worked up for immunosuppression with current (HBsAg or HBV DNA positive) or previous HBV (anti-HBcAb Ab positive) from haematology, oncology, rheumatology and dermatology clinics. Electronic patient records were reviewed to determine the management of those identified with current or previous HBV who were treated with immunosuppression.

Results

A total of 521 patients were HBsAg positive (current HBV) or anti-HBcAb +ve, HBsAg negative (previous HBV). Of these, 25 had passive acquisition of anti-HBcAb so were excluded, leaving 496 patients (53 current HBV and 443 previous HBV). Detection has increased over the time (figure 1). Of the 496 patients, 302 (61%) ultimately received immunosuppression. 31 of the 32 (97%) patients with current HBV were treated with antiviral therapy prior to immunosuppression. One patient with current HBV who was not tested prior to immunosuppression (MMF) developed an acute severe HBV flare. 31 of 270 (11%) patients with past HBV were initiated on antiviral prophylaxis as per guidelines. Worryingly, 17 patients (41%) who were treated with rituximab, which is associated with a high risk HBV reactivation, were not on initiated prophylactic antivirals. The majority of these were before 2018. We observed HBV reactivation in four (11%) rituximab treated patients (1 despite on lamivudine, 1 lamivudine stopped 3 month post-rituximab and 2 never received prophylactic antivirals).

Conclusions

There has been a large rise in the detection of current and past HBV infection since the introduction of HBV testing in individuals receiving immunosuppresssion. Despite the introduction of a Trust guideline, a significant proportion of patients at high risk of HBV reactivation were not initiated on antiviral prophylaxis. HBV reactivation was seen in 11% of patients on rituximab therapy.