1 Department of Transplantation Medicine, Clinic of Surgery, Inflammatory Diseases and Transplantation, Oslo University Hospital Rikshospitalet, Oslo, Norway. t.h.karlsen@medisin.uio.no.
2 Research Institute for Internal Medicine, Clinic of Surgery, Inflammatory Diseases and Transplantation, Oslo University Hospital Rikshospitalet and University of Oslo, Oslo, Norway. t.h.karlsen@medisin.uio.no.