Evaluation of a Hepatitis B Virus Reactivation Prevention Program in Lymphoma Patients Receiving Immunochemotherapy
Authors: Sanchez-Gonzalez Blanca , Garcia-Retortillo Montserrat , Murcia Teresa , Ferraro Mariana , Garcia-Pallarols Francesc , Gimenez Dolors , Montesdeoca Sara , Gimeno Eva , Abella Eugenia , Sola Ricard , Besses Carlos , Salar Antonio 
Published: October 2019

Abstract
INTRODUCTION
Chemotherapy-induced hepatitis B virus (HBV) reactivation is a well-recognized complication and is a potentially life-threatening condition in cancer patients with chronic HBV (hepatitis B surface antigen [HBsAg]-positive).
Rituximab has been associated with an increase in HBV reactivation in chronic HBV patients (45%) and even in patients with resolved infection (HBsAg negative and hepatitis B core antibody [anti-HBc]-positive (22%); however, the reported frequency varies among different studies.
Current guidelines for management of chronic HBV recommend routine antiviral HBV prophylaxis with lymphoma before starting chemotherapy. In contrast, there is little evidence-based consensus regarding patients with resolved HBV infection.
Aim: To analyze the incidence of HBV reactivation and the role of antiviral HBV prophylaxis in lymphoma patients with chronic HBV or resolved HBV treated with chemotherapy, immunotherapy or immunochemotherapy managed according to our institutional HBV guidelines. Secondary endpoints were to analyze the incidence of HBV in this population and HBV guidelines adherence.
PATIENTS AND METHODS
Lymphoma patients with chronic HBV or resolved HBV in a single center.
HBV viral status definitions: Active Chronic HBV infection: HBsAg positive, anti-HBc positive and HBV DNA >2000 IU/mL; Inactive Carriers: HBsAg positive, Anti-HBc positive, HBV DNA undetectable or <2000 IU/mL with normal transaminases; Resolved HBV: HBsAg negative, anti-HBc positive, HBV DNA undetectable.
HBV reactivation was defined as increased serum HBV DNA (≥1 log10), regardless of liver biochemistry or HBsAg status.
Institutional HBV guidelines: serum samples were collected at baseline for HBsAg and anti-HBc testing in all lymphoma patients. Patients were evaluated by a hepatologist if any of them fulfilled HBV viral status definition. Baseline at screening and monitoring every 3 months during therapy and up to 24 months after completing therapy (assessment of liver biochemistry, serum HBV DNA, HBsAg and anti-HBs levels). Specific prophylaxis strategies according to HBV status: Group A (Active chronic HBV): treatment for HBV; Group B (Inactive carriers): antiviral HBV prophylaxis; Group C (Resolved HBV): antiviral HBV prophylaxis if rituximab containing-therapy or follow-up only if rituximab-free therapy. HBV antiviral prophylaxis was started before therapy and finished 12 months after completing therapy.
RESULTS
From January 2012 to January 2015, 227 lymphoma patients received chemotherapy or immunochemotherapy. 142 (63%) patients received rituximab-containing therapy. 43 (19%) patients were anti-HBc positive. Group A: 2 (1%) patients; Group B: 2 (1%) patients; Group C: 39 (17%) patients. 14 (6%) patients have coinfection with hepatitis C virus and 12 (5%) patients co-infection with human immunodeficiency virus (HIV). Adherence to HBV guidelines was 90%. Patients in Group A (n=2) and B (n=2) received antiviral treatment/prophylaxis before starting therapy. In the Group C, 16 (41%) patients underwent only follow-up and 23 (59%) patients received HBV antiviral prophylaxis (lamivudine in 4, entecavir in 8 and tenofovir in 11). Median duration of HBV prophylaxis was 18 months (95% CI: 16-19 months). After a median follow-up of 21 months, 2 patients developed HBV reactivation during lymphoma treatment: 1 from group B (reactivation rate of 50%) and 1 from group C (reactivation rate of 3%). Both patients had received rituximab-containing treatment and both developed HBV reactivation (without hepatitis flare) within the first 6 months after finishing antiviral HBV prophylaxis (delayed HBV reactivation). Outcome was favorable in both patients. Characteristics of HBV reactivation patients are shown in table I. Cumulative incidence of HBV reactivation at 12 and 24 months were 0% and 8%, respectively.
CONCLUSION
Our strategy of close monitoring patients with chronic HBV or resolved HBV that receive chemotherapy and adding antiviral HBV prophylaxis only in selected patients clearly decrease HBV reactivation. Nevertheless, this strategy may not fully protect patients from late HBV reactivations. Larger validation studies are needed to confirm our data and to establish the best cost-effective strategy in this lymphoma population, especially in the new era of inmunomodulatory drugs of their real involvement in HBV reactivation is unknown.
Table 1 Table 1.

Disclosures
No relevant conflicts of interest to declare.