Tofacitinib for the treatment of antineutrophil cytoplasm antibody-associated vasculitis: a pilot study.

Antineutrophil cytoplasm antibody-associated vasculitis (AAV) is a group of necrotising vasculitis involving small vessels characterised by upper and lower respiratory tract, kidney, eye, ears–nose–throat, skin, gastrointestinal and neurological involvement. AAV includes granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA).1 To date, maintenance therapy to prevent disease relapse remains the main therapeutic challenge for patients with AAV. Previous studies indicate that T cells and associated cytokine production (eg, interleukin (IL)-6, IL-10, IL-12, IL-23 and type l interferons) play an important role in the pathogenesis of AAV2–4 via activation of the Janus kinase (JAK)/signal transducer and activator of transcription pathway.5 Tofacitinib is a JAK1/3 inhibitor that functions by suppressing the activity of the JAK family of non-receptor tyrosine kinases (RTKs) and has been used successfully for the treatment of rheumatoid arthritis, psoriatic arthritis, Behcet’s disease and systemic lupus erythematosus6–9; however, the use of tofacitinib for the treatment of AAV has not been reported. Of particular interest, imatinib mesylate, an RTK inhibitor, has been reported to be an effective treatment for patients with EGPA.10 Therefore, we hypothesised that tofacitinib-mediated inhibition of JAK signalling …