Footnotes

• Contributors Study design: RW, PC, BL, GV, FVdB, DE. Data collection: RW, PM, BL. Data analysis: RW. Data interpretation: RW, BL, PC, FVdB, DE. Writing of the report: RW. All authors approved the final version of the manuscript.

• Funding This work concerns an investigator-initiated study supported by UCB Pharma.

• Competing interests None.

• Patient consent Obtained.

• Ethics approval Ethics Committee of Ghent University Hospital, Belgium.

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