Proposal for a definition for response to treatment, inactive disease and damage for JIA associated uveitis based on the validation of a uveitis related JIA outcome measures from the Multinational Interdisciplinary Working Group for Uveitis in Childhood (MIWGUC)

Background JIA-associated uveitis (JIAU) is a serious, sight-threatening disease with significant long-term complications and risk of blindness, even with improved contemporary treatments. The MIWGUC was set up in order to propose specific JIAU activity and response items and to validate their applicability for clinical outcome studies. Methods The group consists of 8 paediatric rheumatologists and 7 ophthalmologists. A consensus meeting took place on November 2015 in Barcelona (Spain) with the objective of validating the previously proposed measures. The validation process was based on the results of a prospective open, international, multi-centre, cohort study designed to validate the outcome measures proposed by the initial MIWGUC group meeting in 2012. The meeting used the same Delphi and nominal group technique as previously described in the first paper from the MIWGUC group (Arthritis Care Res 64:1365-72, 2012). Patients were included with a diagnosis of JIA, aged less than 18 years, and with active uveitis or an uveitis flare which required treatment with a disease-modifying anti-rheumatic drug. The proposed outcome measures for uveitis were collected by an ophthalmologist and for arthritis by a paediatric rheumatologist. Patient reported outcome measures were also measured. Results A total of 82 patients were enrolled into the validation cohort. Fifty four percent (n = 44) had persistent oligoarthritis followed by rheumatoid factor negative polyarthritis (n = 15, 18%). The mean uveitis disease duration was 3.3 years (SD 3.0). Bilateral eye involvement was reported in 65 (79.3%) patients. The main findings are that the most significant changes, from baseline to 6 months, are found in the AC activity measures of cells and flare. These measures correlate with the presence of pre-existing structural complications and this has implications for the reporting of trials using a single measure as a primary outcome. We also found that visual analogue scales of disease activity showed significant change when reported by the ophthalmologist, rheumatologist and families. The measures formed three relatively distinct groups. The first group of measures comprised uveitis activity, ocular damage and the ophthalmologists' VAS. The second comprised patient reported outcomes including disruption to school attendance. The third group consisted of the rheumatologists' VAS and the joint score. Conclusions We propose distinctive and clinically significant measures of disease activity, severity and damage for JIAU. This effort is the initial step for developing a comprehensive outcome measures for JIAU, which incorporates the perspectives of rheumatologists, ophthalmologists, patients and families.