Factors Influencing Hepatitis B Virus Reactivation in Lymphoma Patients Treated With Rituximab

Description of factors associated with Hepatitis B virus reactivation: * Laboratory parameters defining HBV status/activity at time of treatment initiation * Lymphoma stage at rituximab treatment initiation (Ann Arbor, B-symptoms, bone marrow involvement, IPI, ECOG-score, LDH) * Immunochemotherapy regimen (treatment line, rituximab dose and cycle) * Disease status at time of HBV reactivation * Antiviral prophylaxis (medication, dose, duration at time at time of reactivation) * Patient demographics (age, gender, residence, ethnic origin, smoking status, alcohol consumption and occupation) Time to Hepatitis B virus reactivation * The time from start of rituximab-containing immunochemotherapy until first evidence of HBV reactivation meeting the criteria * Description of prophylaxis and treatment with antiviral medication HBV vaccination Time of initiation of antiviral therapy of prophylaxis relating to clinical or laboratory signs of possible HBV reactivation Anti-viral medication used in prophylaxis or therapy * Description of outcomes Outcomes of the HBV reactivation Outcomes of the rituximab-containing immunochemotherapy Demographics and previous infection history: Age, gender, nationality, race, social history, past medical history * Parameters associated with lymphomas: Ann Arbor stage, number of extranodal involvement, serum LDH, serum β2-microglobulin, ECOG performance status, presence of B symptoms, International Prognostic Index, bone marrow invasion * Laboratory parameters associated with hepatitis B virus: hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti- HBs), hepatitis B e antigen (HBeAg), hepatitis B core antibody (anti-HBc), hepatitis B e antibody (anti-HBe), serum HBV DNA * Lymphoma treatment history: Line of treatment (first line, second line), rituximab and chemotherapy administration (dose, schedule), start date, last treatment date * Prophylaxis or treatment against HBV reactivation: antiviral drug (dose, schedule, duration) * Hepatitis B virus reactivation: onset, serologic markers, outcome