1. Department of Internal Medicine Diakonie Hospital Stuttgart Stuttgart Germany
2. Department of Internal Medicine III University Hospital Ulm Ulm Germany
3. Department of Otorhinolaryngology University Hospital Ulm Ulm Germany
4. Department of Internal Medicine V University Hospital Heidelberg Heidelberg Germany
5. Institute for Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Donation Service Baden‐Württemberg‐Hessen and Institute for Transfusion Medicine University of Ulm Ulm Germany
6. Department of Biomedical Sciences University of Hull Hull UK