Chronic illness requiring long term immunosuppressive treatment and the side effects it entails present a large burden on health care and social systems. Information on actual cost or cost reduction is available for cancer and its treatment, however is very limited for autoimmune diseases. We estimate that more precise monitoring of disease activity, infectious side effects and extending disease free intervals in potentially up to 70% of patients, will not only improve quality of life but substantially reduce cost of health care. RELENT will implement measures to calculate cost-effectiveness and value of different forms of treatment to document the economic impact of the research results.