1. Paediatric Department, Oslo University Hospital and Faculty of Medicine, University of Oslo, Oslo, Norway
2. Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
3. Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
4. Intervention Centre and Department of Surgery, Oslo University Hospital and Faculty of Medicine, University of Oslo, Oslo, Norway
5. Division of Cancer Medicine, Surgery and Transplantation, Oslo University Hospital and Faculty of Medicine, University of Oslo, Oslo, Norway
6. Department of Endocrinology, Oslo University Hospital and Faculty of Medicine, University of Oslo, Oslo, Norway
7. Division of Paediatrics, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden