Link to Pubmed [PMID] – 35199139
Link to DOI – keac10710.1093/rheumatology/keac107
Rheumatology (Oxford) 2022 Feb; ():
To assess the efficacy and tolerance of the conventional first-line treatment by methotrexate (MTX) and corticosteroids (CS) in patients with juvenile dermatomyositis (JDM) regardless of severity.We conducted a monocentric retrospective study of patients with newly-diagnosed JDM treated with MTX and CS from 2012 to 2020. Proportion of clinically inactive disease (CID) within six months of MTX initiation was evaluated using both PRINTO criteria (evaluating muscle inactive disease) and Disease Activity Score (evaluating skin inactive disease). We compared responders and non-responders using univariate analyses.Forty-five patients with JDM, out of which thirty (67%) severe JDM, were included. After six months of treatment with MTX and CS, complete CID, muscle CID and skin CID were achieved in 14/45 (31%), 19/45 (42%) and 15/45 (33%) patients respectively. The absence of myositis-specific (MSA) or myositis-associated autoantibodies (MAA) at diagnosis was associated with a better overall, cutaneous and muscular therapeutic response, compared with antibody-positive forms (p< 0.01). Requirement for ICU (p= 0.029) and cutaneous ulcerations (p= 0.018) were associated to a less favorable muscle response. MTX was stopped due to intolerance in six patients (13%) before month 6.Conventional first-line treatment with MTX was not efficient in a large subset of JDM patients, especially in patients with MSA-positive forms, and in patients with severe JDM. Larger multicentre cohorts are required to confirm these data and to identify new predictive biomarkers of MTX response, in order to treat patients with JDM as early as possible with appropriate targeted drugs.