AB0203 Clinical phenotype and ultrasound characteristics of rheumatoid arthritis flare after discontinuation of conventional synthetic dmards

Background Current protocols based on early and intensive treatment with csDMARDs in rheumatoid arthritis (RA) have allowed the achievement of remission in a considerable proportion of the patients and opened the perspective, in selected cases, of a drug-free monitoring scheme. Treatment discontinuation can lead, however, to possible recurrence of joint inflammation and clinical flare. Understanding the dynamics acting upstream these events remains a fundamental research task with direct clinical and patho-biologic implications. Objectives To delineate the clinical, serological and ultrasonographic changes associated to a drug-free flare in patients discontinuing csDMARD after achievement of stable remission. Co-primary objective was to compare, through a retrospective analysis in the same patients, these changes with early features of the pathology at onset, before treatment introduction. Methods 92 RA patients in stable DAS28 remission following a DAS-steered treatment strategy with MTX were recruited in our Centre and introduced to a drug-free monitoring scheme according to the following inclusion criteria: a) treatment introduced within 12 months from symptoms’ onset, b) at least 24 months of continuative treatment, c) DAS28 Results A total drug-free follow-up of 1398 person-months was analysed with a median (IQR) of 156–24 months. Thirty-eight patients (27/38 in ACR/EULAR Boolean remission, 16/38 with PD score=0 at withdrawal visit) required treatment re-introduction after a median (IQR) time from discontinuation of 63–9 months (range 3–18). DAS28 variations at re-treatment showed a mean (SD) increase of 2.26 (1.03), reflecting significant differences in all DAS components (p Conclusions Drug-free clinical flare can occur over a wide temporal window, in the absence of detectable signs of inflammation at the time of treatment discontinuation. It can associate with ex-novo recurrence of US pathologic changes at joint and tendon level, reproducing some of the quantitative/qualitative features of disease onset. Disclosure of Interest None declared