1. Department of Neurology, University Hospital Essen, University of Duisburg-Essen , D-45122 Essen , Germany
2. Department of Clinical Neurosciences and National Institute for Health Research (NIHR) Biomedical Research Centre, University of Cambridge , Cambridge CB2 0AH , UK
3. Department of Metabolism, Digestion and Reproduction, Imperial College London , London W12 0NN , UK
4. Institute of Transfusion Medicine, University Hospital Essen, University of Duisburg-Essen , D-45147 Essen , Germany