Clinical Guidelines for Malignant Lymphoma Combined with Hepatitis B Virus Infection 1.All patients with a definite diagnosis of malignant lymphoma and planning to receive chemotherapy or immunochemotherapy should receive hepatitis B two-half-pair test. 2, HBsAg or HBeAg positive patients should be tested for HBV DNA. 3, HBsAg positive or HBV DNA ≥103 copy number should be given prophylactic anti-hepatitis B virus treatment before receiving chemotherapy or immunochemotherapy. It is recommended that prophylactic antiviral therapy be given for at least 1 week before chemotherapy and that antiviral therapy be continued until 6 months after the completion of chemotherapy or immunochemotherapy. Prophylactic anti-hepatitis B virus drugs: e.g. lamivudine 100mg/day, adefovir 10mg/day. Entecavir 0.5mg/day. 4, Hepatitis B patients should meet the following indicators before receiving chemotherapy: normal liver function, HBV DNA <105 copy number. During chemotherapy, liver function should be closely monitored, and those with abnormal liver function should have their HBV DNA rechecked in time; if reactivation of hepatitis B virus still occurs after prophylactic application of antiviral therapy, they should go to Infectious Diseases Department for consultation.