1. Department of Internal Medicine, Division of Nephrology and Clinical and Experimental Immunology, Maastricht University Medical Center, 6229 HX Maastricht, The Netherlands
2. Department of Cardiology, Maastricht University Medical Center, 6229 HX Maastricht, The Netherlands
3. Central Diagnostic Laboratory, Maastricht University Medical Center, 6229 HX Maastricht, The Netherlands