1. Division of Medicine; Centre for Rheumatology; Rayne Institute; University College London (UCL); London UK
2. Division of Rheumatology; Department of Clinical Sciences and Community Health; Istituto G Pini; University of Milan; Milan Italy
3. IRCCS Istituto Auxologico Italiano; Milan Italy*
4. Arthritis Research UK Centre for Adolescent Rheumatology; UCL; UCL Hospital and Great Ormond Street Hospital; London UK