Efficacy Of Upadacitinib In Psoriatic Arthritis And Comparison To Rheumatoid Arthritis.

This is a multicentric prospective observational study in which consecutive patients diagnosed with Psoriatic Arthritis (any subset) and Rheumatoid Arthritis, that according to clinicians' evaluation should be treated with Upadacitinib therapy, will be recruited from the outpatient clinic of the Rheumatology Department of the centers included in the study. The investigators will enroll consecutive patients with Psoriatic Arthritis and Rheumatoid Arthritis with active disease and fulfilling the inclusion and exclusion criteria, from the outpatient clinic of the Rheumatology Units of the participating centers. Written informed consent will be obtained prior to the beginning of the study. All patients, in line with clinical routine practice, will undergo a standard clinical, laboratory, and imaging assessment in order to define the disease activity according to standardized disease activity indexes, at baseline and during the first 3 follow-up visits. For patients starting new treatments for Psoriatic Arthritis and Rheumatoid Arthritis, the follow-up visits are generally scheduled after 1 month (± 1 week), 3 months (± 2 weeks), and 6 months (± 4 weeks) post-treatment initiation, in accordance with international guidelines and local protocols. In case of suspicion of axial involvement, an MRI of the sacroiliac joints will be performed at baseline and, in case of positivity, will be repeated after 6 months (±1 month) in order to assess disease activity at the spine and the treatment efficacy. Regarding the Patient Reported Outcome, the investigators will assess these during the scheduled visits, and two weeks after the initiation of treatment to evaluate earlier pain and functional improvement. The Patient Reported Outcome assessment at two weeks will be administered in a paper form to participants during the baseline visit, and subsequently participants will return these during the first follow-up visit. The data for the study will be retrieved from the medical records of participants and recorded into an appositely created electronic case report form.