Clinical, biological, and radiological changes under therapy, and criteria for clinical response and remission in adult-onset Still's disease: a systematic literature review informing the development of the European Alliance of Associations for Rheumatology (EULAR) criteria for assessing disease activity.

Objectives: A task force commissioned by the European Alliance of Associations for Rheumatology was set up for the Methods: The PubMed MEDLINE, EMBASE, and Web of Science databases were screened for eligible articles published between January 1990 and September 2021. Abstracts from 2018 to 2021 EULAR, ACR, and ISSAID conferences were also browsed. We included randomised controlled trials (RCTs), quasi-RCTs, cohort studies and case series of ≥ 4 patients describing changes under therapy, with a minimum follow-up of 4 weeks. The risk of bias was assessed using the National Institute of Health Quality Assessment Tool. Results were synthesised descriptively. Results: Sixty-three studies (including 2889 patients) were selected. Four were RCTs or quasi-RCTs, and 59 were observational studies. Most of the studies were retrospective (n = 58) and of poor quality. The most often reported clinical characteristics were fever, cutaneous rash, arthralgia and/or arthritis, hepatosplenomegaly, and sore throat. The most often reported laboratory parameters were leukocyte count, erythrocyte sedimentation rate, serum C-reactive protein and ferritin levels, all of which decreased with treatment. Definitions of response, remission and relapse, disease activity composite indices and patient-reported outcomes were heterogeneous. Conclusions: Based on the identified variables, we can aim for a subsequent establishment and validation of a new measure to improve and standardise the management of patients with AOSD.