Footnotes

• Twitter @FergaGleeson

• Contributors All authors: have made substantial contributions and satisfy the criteria for authorship, conception and design, analysis and interpretation of the data, drafting of the article, critical revision of the article for important intellectual content, final approval of the article, collection of samples and clinical data, generation of experimental data and revision of the manuscript and approval of the final version. FCG and AGGdP: study design, analysis and interpretation of data and drafting of the manuscript. All authors agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. FCG is the sole contact for the editorial process.

• 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, or conduct, or reporting, or dissemination plans of this research.

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