1. Department of Internal Diseases, Riga Stradins University , Riga , Latvia
2. Program in Cellular and Molecular Medicine, Boston Children’s Hospital, Harvard Medical School , Boston, MA , USA
3. Department of Doctoral Studies, Riga Stradins University , Riga , Latvia
4. Joint Laboratory, Pauls Stradins Clinical University Hospital , Riga , Latvia
5. Programa Disciplinario de Inmunología, ICBM, Facultad de Medicina, Universidad de Chile , Santiago , Chile
6. Centre for Adolescent Rheumatology Versus Arthritis at UCL, UCLH and GOSH and Department of Rheumatology, Division of Medicine, University College London , London , UK