Ultrasound in PSoriatic Arthritis TREAtMent - UPSTREAM

BACKGROUND Psoriatic arthritis (PsA) is a systemic inflammatory disease with articular and extra-articular features. To date remission is considered to be the ultimate goal of therapy in PsA, however, due to the characteristics of the disease with involvement of different domains, remission may be difficult to achieve and maintain and so a minimal disease activity (MDA) could be an acceptable goal. In view of the therapeutic target of remission or MDA, the identification of adverse prognostic factors and the best treatment strategy are two of the most important items in research agenda of PsA. Establishing the prognosis of a patient with PsA is hence important to define the treatment strategy. Currently, observational and prospective cohort studies have identified prognostic factors correlating with the achievement of therapeutic response. Nevertheless, despite the importance of identifying prognostic factors in a disease with a functional disability comparable to rheumatoid arthritis (RA), the studies are still limited. Undoubtedly, the concept of treat-to-target (T2T) in PsA needs further studies, especially with longer follow up and larger samples. In T2T strategies, it is necessary to quantify the disease activity and this is possible by composite indices. The heterogeneity of PsA including axial and peripheral involvement and specific features (i.e. dactylitis, enthesitis) as well as extra-articular features makes the use of a single composite index (e.g. Disease Activity for Psoriatic Arthritis-DAPSA, Composite Psoriatic Disease Activity Index-CPDAI) a challenge not resolved yet. An interesting possibility is to integrate musculoskeletal ultrasonography (US) with clinical examination to stratify patients and to decide treatments in a T2T strategy. In the last years the role of imaging is grown up and EULAR recommendations on the use of imaging techniques in chronic arthritis recognize the high sensitivity of US to detect disease activity better than clinical examination alone although the utility of US in clinical practice is not supported by sufficient evidence yet

AIM

The aim of this study is to identify clinical and US predictors of achieving MDA in PsA patients with active peripheral arthritis starting a new course of therapy.

Identifying prognostic factors of achieving remission or low disease activity will allow a better selection of patients with poorer outcome and a following improvement of the therapeutic strategies. Furthermore the possibility that US could be an added prognostic value makes this study a clear example of integration between the clinic and US. This study will respond to the need of tailoring treatment that would allow clinicians to practice a more effective and personalized medicine, optimizing the outcomes of patients with PsA as well as the treatments management.

STUDY OBJECTIVES