JAK inhibition for treatment of psoriatic arthritis in Down syndrome
People with Down syndrome (DS), the condition caused by trisomy 21 (T21), display increased prevalence of several autoimmune conditions relative to the general population, including autoimmune thyroid disease (AITD), celiac disease, autoimmune skin conditions and arthropathies. Although it is now well established that T21 causes hyperactivation of IFN and downstream Janus kinase (JAK) signalling, the therapeutic value of this observation remains to be defined. Here, we describe the first reported case of an individual with DS who was effectively treated with the JAK inhibitor tofacitinib as a first-line therapy for severely debilitating psoriatic arthritis.