1. Renal Transplant Unit; Division of Internal Medicine; Department of Nephrology; Academic Medical Center; Amsterdam; the Netherlands
2. Department of Pathology; Academic Medical Center; Amsterdam; the Netherlands
3. Department of Nephrology; Leiden University Medical Center; Leiden; the Netherlands
4. Renal Transplant Unit; Division of Internal Medicine; Department of Nephrology; Groningen University Hospital; Groningen; the Netherlands