Introduction: The medical treatment of inflammatory rheumatic diseases has improved dramatically during the last decades primarily due to the introduction of biological disease modifying anti-rheumatic drugs (bDMARDs). However, bDMARD treatment failure occurs in 30-40% of patients due to lack of effectiveness or side effects. The tools to predict treatment outcomes in the individual patient are currently limited. The objective of the present study is to identify diagnostic, prognostic and predictive biomarkers, which can be used to 1) diagnose inflammatory rheumatic diseases early in the disease course with high specificity and sensitivity, 2) improve prognostication or 3) predict treatment effectiveness and tolerability for the individual patient.