Successful treatment of an anti-MDA5 antibody-positive Juvenile Dermatomyositis patient with refractory interstitial lung disease using tofacitinib

Juvenile dermatomyositis (JDM) is a rare autoimmune disorder affecting children, mainly characterized by skin rash and muscle weakness (1). Anti-MDA5 antibody-positive JDM represents a distinct phenotype of disease with a high risk of developing life-threatening progressive interstitial lung disease (ILD)(2). The pivotal role of the type I interferon (IFN) pathway in the pathogenesis of anti-MDA5 positive JDM has prompted the exploration of Janus kinase (JAK) inhibitors as a therapeutic option (3). Nevertheless, while the efficacy and safety of JAK inhibitors have been established in clinical trials including adult-onset anti-MDA5-antibody positive DM (4), evidence in paediatric cases with progressive or refractory ILD is limited. In this report we describe the efficacy and safety of tofacitinib, a JAK 1/3 inhibitor, in treating an anti-MDA5-positive JDM young girl with refractory ILD, highlighting the potential of JAK inhibitors as targeted therapy in these patients.