1. Department of Surgery A, University of Oslo, The National Hospital, N‐0027 Oslo, Norway
2. Department of Immunology and Blood Bank, Norwegian University for Science and Technology, N‐7006 Trondheim, Norway
3. Institute of Immunology and Rheumatology, University of Oslo, The National Hospital, N‐0027 Oslo, Norway
4. Department of Pathology, University of Oslo, The National Hospital, N‐0027 Oslo, Norway
5. Department of Surgery B, University of Oslo, The National Hospital, N‐0027 Oslo, Norway
6. Department of Immunology and Transfusion Medicine, Nordland Central Hospital, Norway