Statistics from Altmetric.com
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 the multipathway inhibitory effect of tofacitinib might contribute to its efficacy in refractory SAPHO syndrome.
The heterogeneity of treatment response also raises the issue of stratified treatment approach in SAPHO syndrome. Clinical and genetic markers have been identified using machine learning to enable prediction of treatment responses to anti-TNF agents in rheumatoid arthritis.11 Furthermore, Miyagawa et al proved that strategic treatment based on immunological phenotypes of the individual patient yielded a significant decrease in disease activity compared with routine treatment in PsA.12 Given the high heterogeneity of SAPHO syndrome, we believe that further efforts in precision medicine may facilitate the understanding and management of the disease.
As mentioned by Xie et al, our retrospective study had a limited sample size and follow-up time. It was the first step to demonstrate a new potential treatment for SAPHO syndrome. Future controlled perspective study with a larger sample size and longer follow-up duration is required to establish the efficacy and safety of tofacitinib in SAPHO syndrome.
Handling editor Josef S Smolen
Contributors YL and YC prepared the manuscript and contributed equally to this article. All the authors have critically revised and approved the manuscript.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Patient and public involvement Patients and/or the public were not involved in the design, conduct, reporting or dissemination plans of this research.
Patient consent for publication Not required.
Provenance and peer review Commissioned; internally peer reviewed.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.