Efficacy of Upadacitinib in refractory Polyarteritis Nodosa: a case report.

Polyarteritis nodosa (PAN) is systemic vasculitis, typically treated with a combination of glucocorticoids and immunosuppressants. Changing the immunosuppressant is recommended if remission cannot be achieved with these treatments. However, there is a lack of further treatment options for patients who are unresponsive to all immunosuppressants. We report a 44-year-old Japanese man with refractory PAN who was unresponsive to various immunosuppressants (including tocilizumab). Upadacitinib treatment led to relatively rapid symptom improvement, allowing for tapering and eventual discontinuation of immunosuppressants, including prednisolone. During his 1-year follow-up, no relapse or side effects were noted. This case suggests that Janus kinase inhibitors may provide a breakthrough for patients with refractory PAN.