MEASURING DISEASE ACTIVITY IN PSORIATIC ARTHRITIS

Psoriatic Arthritis (PsA) is an infl ammatory rheumatic disease predominantly aff ecting joints and skin as well as other organ systems. Th e “treat to target“ concept and the attempt to achieve strict disease control implies the usage of a measuring instruments for the evaluation of disease activity and assessment of treatment eff ectiveness in routine clinical practice as well as in clinical studies. Initially, measuring instruments designed for other diseases, primarily for rheumatoid arthritis (RA) and spondylarthritis (SpA), were used. During the past decade, initiated by the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) and the Outcome Measures in Rheumatology Clinical Trials (OMERACT), specifi c composite measures of disease activity which include diff erent domains of PsA, have been introduced. Th ere is a tendency to evaluate and categorize disease activity as high, moderate, low, and minimal, while remission is still not well defi ned in respect of the highly heterogeneous clinical presentation and course of the disease. Th e application of specifi c disease activity measures and indexes in routine clinical practice is desirable and necessary, but is diffi cult to achieve due to their complexity and the time required for implementation. Further eff orts by expert groups are focused on a better validation and standardization of instruments for measuring and monitoring PsA activity as well as treatment eff ectiveness in reaching the treatment goal, which is minimal disease activity, with the ultimate goal of achieving and defi ning remission.