ABSTRACT

Glucocorticoids (GCs) are still the mainstay of treatment in systemic vasculitides. Immunosuppressive agents such as cyclophosphamide, rituximab, azathiopurine, and mycophenolate mofetil are chosen as steroid sparing agents according to the type of vasculitis. Biologic treatments such as tumor necrosis facto inhibitors and tocilizumab are used in particularly large vessel vasculitis (LVVs) for refractory patients. Janus kinase (JAK)-signal transduction activator of transcription (JAK/STAT) pathway activation is involved in the pathogenesis of several inflammatory diseases. JAK inhibitors were also approved for the treatment of rheumatoid arthritis (RA), psoriatic arthritis, and ulcerative colitis. However, there are very limited data including mostly case series and open studies with JAK inhibitor usage in systemic vasculitides. Current data mostly come from LVVs and some from Behçet’s disease. In the light of current data, we are quite far from suggesting the common usage of JAK inhibitors in systemic vasculitides. JAK/STAT pathway inhibition also may cause severe complications in these group of patients treated with higher dose GC and more potent immunosuppressives compared to RA and ankylosing spondylitis. Although we have limited data showing the efficacy of the JAK inhibitors for systemic vasculitis treatment, they may be used in patients refractory to standard immunosuppresives. JAK inhibitors seem to be promising therapeutic agents, especially for treating LVV. There are ongoing controlled studies with tofacitinib and upadacitinib in TAK; upadacitinib and baricitinib in GCA. Larger and controlled studies will clarify the efficacy and safety of JAK inhibitors in the treatment of systemic vasculitides.

Keywords: JAK inhibitors, treatment, vasculitis