High rate of hepatitis B viral breakthrough in elderly non-Hodgkin lymphomas patients treated with Rituximab based chemotherapy

BACKGROUND: Rituximab-containing chemotherapies are offered to elderlies for treatment of non-Hodgkin lymphomas (NHL). From 0.7 to 27% of patients with "resolved" HBV infection develop HBV reactivation and related hepatitis during Rituximab-containing chemotherapies. Currently, several antiviral drugs are available for the prophylaxis of patients at risk for HBV reactivation, which include lamivudine, tenofovir, entecavir, and adefovir. Viral breakthrough may occur during therapy, which is defined as an abrupt increase in serum HBV DNA levels after a period of persistent suppression. Viral breakthrough occurs with non-compliance to therapy and, also, when drug-resistant mutants emerge. The risk might be higher in fragile patients as elderlies. AIMS: Since no study addressed this question, we determined the rate of HBV-RS in patients >65years undergoing Rituximab-containing chemotherapies for NHLs. METHODS: We evaluated 85 newly diagnosed NHL patients with resolved HBV infection, receiving Rituximab-containing chemotherapies. All received lamivudine. HBV DNA was checked at baseline, every 4 weeks, for 1year after completion of Rituximab cointaining regimens. RESULTS: Nine patients (10%) had HBV reactivation and HBV related hepatitis. All received entecavir and recovered without consequences. HBV reactivation was more likely to occur after an average of five R-CHOP cycles or during Fludarabine. CONCLUSIONS: The rate of viral breakthrough (VBK), in our study population, is high considering that the patients were HBV DNA negative at baseline and suggest that Lamivudine prevention may not be sufficient in this population.