Footnotes

• Handling editor Josef S Smolen

• Contributors HW was involved in data acquisition, analysis and interpretation of the data. SS and ND were involved in the design, data acquisition, and analysis and interpretation of the data. BD, BH, GH and JC were involved in the design and analysis and interpretation of the data. All authors were involved in drafting of the work or revising it critically for important intellectual content. All authors approved the final version to be published and agree to be accountable for all aspects of the work.

• Funding This study was funded by a University of Auckland summer studentship awarded to H Wang.

• Competing interests ND has received consulting fees, speaker fees or grants from AstraZeneca, Horizon, Amgen, Selecta, Arthrosi, Dyve BioSciences, Hengrui. Abbvie and Janssen, outside the submitted work.

• Patient and public involvement Patients and/or the public were involved in the design, or conduct, or reporting, or dissemination plans of this research. Refer to the Methods section for further details.

• Provenance and peer review Not commissioned; externally peer reviewed.