1. Institute of Medical Microbiology, Immunology and Hygiene, Technische Universität München, Trogerstrasse 9; D-81675 Munich Germany
2. Franz-Volhard-Klinik am MDC, Department of Nephrology, Wiltbergstrasse 50; D-13122 Berlin Germany
3. Department of Paediatrics and Internal Medicine, University of Ulm, Robert-Koch-Strasse 8; D-89081 Ulm Germany