Analysis of the clinical characteristics and therapeutic effect of refractory juvenile dermatomyositis to tofacitinib

Abstract

Objective: To elucidate the clinical features of patients with refractory juvenile dermatomyositis (JDM), and to explore the efficacy and safety of tofacitinib in the treatment of refractory JDM. Methods: A total of 75 JDM patients admitted to the Department of Rheumatology and Immunology in Shenzhen Children's Hospital from January 2012 to January 2021 were retrospectively analyzed, and to analyze the clinical manifestations, efficacy and safety of tofacitinib in the treatment of refractory JDM. Patients were divided into refractory group with using of glucocorticoids in combination with two or more anti-rheumatic drugs for treatment, and the presence of disease activity or steroid dependence after a one-year follow-up. The non-refractory group is defined as clinical symptoms disappeared, laboratory indicators were normal, and clinical remission was achieved after initial treatment, and the clinical manifestations and laboratory indexes of the two groups were compared. The Mann-Whitney U test, Fisher's precision probability test was used for intergroup comparison. Binary Logistic multivariate regression analysis was used to identify risk factors for refractory JDM. Results: Among the 75 children with JDM, 41 were males and 34 were females with a age of onset of 5.3 (2.3, 7.8) years. The refractory group consisted of 27 cases with a age of onset of 4.4 (1.5, 6.8) years, while the non-refractory group consisted of 48 cases with a age of onset of 5.9 (2.5, 8.0) years. Compared with 48 cases in the non-refractory group, the proportion of interstitial lesions and calcinosis in the refractory group was higher than that in the non-refractory group (6 cases (22%) vs. 2 cases (4%), 8 cases (30%) vs. 4 cases (8%), both P<0.05). Binary Logistic regression analysis showed that observation group were more likely to be associated with to interstitial lung disease (OR=6.57, 95%CI 1.22-35.31, P=0.028) and calcinosis (OR=4.63, 95%CI 1.24-17.25, P=0.022). Among the 27 patients in the refractory group, 22 cases were treated with tofacitinib, after treatment with tofacitinib, 15 of 19 cases (86%) children with rashes showed improvement, and 6 cases (27%) with myositis evaluation table score less than 48 score both were improved, 3 of 6 cases (27%) had calcinosis were relieved, and 2 cases (9%) had glucocorticoid-dependence children were successfully weaned off. During the tofacitinib treatment, there was no increase in recurrent infection, blood lipids, liver enzymes, and creatinine were all normal in the 22 cases. Conclusions: Children with JDM with calcinosis and interstitial lung disease are more likely to develop refractory JDM. Tofacitinib is safe and effective for refractory JDM.