1. Clinic for Internal Medicine V; University of Heidelberg; Heidelberg Germany
2. Clinic for Internal Medicine III; University of Ulm; Ulm Germany
3. German Red Cross Blood Transfusion Service Baden-Württemberg-Hessen; Institute of Clinical Transfusion Medicine and Immunogenetics Ulm; Ulm Germany
4. Department of Internal Medicine; Diakonie Hospital Stuttgart; Stuttgart Germany