Response to: 'Off-label use of tofacitinib: a potential treatment option for SAPHO syndrome by Xie et al

We would like to thank Xie et al1 for their interest in our paper2 and for their insights into the possible mechanism of action of tofacitinib in synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome and the trend of stratified medicine.

As Xie et al highlighted, tofacitinib presented clinical and radiological efficacy in patients with SAPHO syndrome who had an inadequate response to tumour necrosis factor (TNF) inhibitors or bisphophonates. Similarly, a clinical trial proved that tofacitinib was effective in patients with TNF inhibitor-resistant psoriatic arthritis (PsA).3 By inhibiting the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway, tofacitinib modulates the network of a wide range of inflammatory cytokines, including interleukin-6 (IL-6), IL-17 and TNF-α, which were potentially involved in the pathogenesis of SAPHO syndrome.4–10 We speculated that...