1. Rheumatology Unit, Department of Medicine, Solna, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden
2. Unit of Clinical Immunology, Department of Clinical Immunology and Transfusion Medicine, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden
3. Department of Medical Sciences, Clinical Chemistry, Uppsala University, Uppsala, Sweden
4. Department of Clinical Physiology, Södersjukhuset, Karolinska Institutet, Stockholm, Sweden