Footnotes

• Contributors RJRP was involved in study design, data collection, analysis and interpretation, in addition to drafting and critical appraisal of the manuscript. AV, EF, HB, MR-J, MC, EB and GW were involved in data collection and analysis, in addition to critical review of the manuscript. ELC was responsible for the original concept and was involved in study design, data collection, analysis and interpretation in addition to drafting and critical appraisal of the manuscript.

• Funding This articleand its investigators are supported by (1) the National Institute of Health Research (NIHR) Biomedical Research Centre, based at Oxford University Hospitals Trust, and (2) Oxfordshire Health Service Research Committee as part of Oxford Hospitals Charity, Oxford. The views expressed in this article are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health.

• Competing interests ELC consults for Viela Bio Pharma for IgG4-RD outside the submitted work. There are no commercial or financial conflicts of interest related to this article.

• Patient and public involvement Regular patient engagement is conducted through the UK IgG4-related disease patient and public involvement group, and a lay summary of this work will appear on the patient pages of the authors' website (https://igg4-rd.ndm.ox.ac.uk).

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