[1] Uppsala University Hospital,Dept of Paediatrics
[2] Helsinki University Hospital,Dept of Paediatrics
[3] University of Gothenburg,Dept of Paediatrics
[4] Århus University Hospital,Dept of Paediatrics
[5] Copenhagen University Hospital,Pediatric Rheumatology Department, Pediatric Clinic II
[6] University Hospital of North Norway,Dept of Paediatrics
[7] Norwegian University of Science and Technology and St.Olav's Hospital,Department of Laboratory Medicine, Children's and Women's Health, and Department of Pediatrics
[8] Uppsala University,Department of Immunology, Genetics and Pathology