adult patients, >/= 18 years of age

severe active rheumatoid arthritis; eligible for treatment with rituximab according to current spc

informed consent to data collection

ongoing contraception (for female patients only)

previous treatment with rituximab (mabthera)

allergy against monoclonal antibodies, respectively chimeric monoclonal antibodies

active severe infection

severe heart failure (nyha class iv) or severe, uncontrolled cardiac disease

treatment in other studies within 3 months before rituximab therapy

pregnancy or breast feeding