1. Department of Internal Medicine V Heidelberg University Hospital University of Heidelberg Heidelberg Germany
2. Department of Internal Medicine II Würzburg University Hospital University of Würzburg Würzburg Germany
3. Institute of Transfusion Medicine and Immunology Medical Faculty Mannheim Heidelberg University German Red Cross Blood Service Baden‐Württemberg—Hessen Mannheim Germany
4. Insititue of Pathology Heidelberg University Hospital University of Heidelberg Heidelberg Germany