High risk of clinical relapse in patients with chronic Hepatitis B virus infection after cessation of prophylactic antiviral therapy for rituximab-containing chemotherapy

Background: Prophylaxis with nucleos(t)ide analogue (NA) is recommended to prevent hepatitis B virus (HBV) reactivation in hepatitis B surface antigen (HBsAg)-positive patients receiving rituximab-based B-cell depletion therapy. However, little is known about the risk of clinical relapse after withdrawal of NA. Methods: We retrospectively analyzed 77 noncirrhotic HBsAg carriers with hematological cancer who received rituximab-containing chemotherapy. All of them received either prophylactic entecavir or tenofovir therapy. The risk of clinical relapse and hepatic decompensation after cessation of NA was explored. Results: Clinical relapse and hepatic decompensation developed in 25 (32.5 %) and 11 (14.3 %) of the patients, respectively, and 2 patients died of hepatic decompensation. Most of the hepatic events occurred within 1 year (20 of 25; 80.0%) after stopping NA. A higher pretreatment viral load (≥2000 vs <2000 IU/mL) was associated with increased risks of clinical relapse (hazard ratio, 3.47; 95% confidence interval, 1.56-7.73) and hepatic decompensation (9.91; 2.14-45.92). Of 51 patients with pretreatment viral load <2000 IU/mL, clinical relapse occurred in 10 (19.6 %) and hepatic decompensation in 2 (3.9%). Conclusions: Pretreatment HBV DNA ≥2000 IU/mL is associated with increased risk of liver-related disease after cessation of prophylactic NA therapy in patients who received rituximab-containing chemotherapy.