Footnotes

• AS and FDC contributed equally. MAG-G and JM share senior authorship.

• Contributors AS, FDC, MAG-G and JM were involved in the conception and design of the study. AS and FDC contributed in the analysis and interpretation of data and in drafting the article. SC, RS, JH-R, MCC, SP-G, JAM-F, LR-R, ICM, CG-V, RB, BS, NO-C, AU, BM-A, JS-M, MJG-V, AH-C, GP, LB, CS and MAG-G collected samples and participated in analysis and interpretation of data. SC, RS, JH-R, MCC, SP-G, JAM-F, LR-R, ICM, CG-V, RB, BS, NO-C, AU, BM-A, JS-M, MJG-V, AH-C, GP, LB, CS, MAG-G and JM revised critically the manuscript draft. All authors approved the final version of the manuscript.

• Funding None.

• Competing interests None.

• Patient consent Obtained.

• Ethics approval Approval from the local ethical committees of all centres involved in the study was obtained in accordance with the tenets of the Declaration of Helsinki.

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