1. Department of Internal Medicine University Medical Center GroningenUniversity of Groningen Groningen The Netherlands
2. Medizinische Klinik für Nephrologie und Internistische Intensivtherapie Charité – Universitätsmedizin Berlin Berlin Germany
3. Division of Clinical Chemistry Department of Laboratory Medicine Karolinska Institutet Stockholm Sweden
4. Clinical Chemistry Karolinska University LaboratoryKarolinska University Hospital Stockholm Sweden