1 Medical Clinic III, Gastroenterology, Metabolic Diseases and Intensive Care, University Hospital RWTH Aachen, Aachen, Germany.
2 Medical Clinic III, Gastroenterology, Metabolic Diseases and Intensive Care, University Hospital RWTH Aachen, Aachen, Germany; Coordinating Center for Alpha-1 Antitrypsin Deficiency-related Liver Disease of the European Reference Network (ERN) "Rare Liver" and the European Association for the Study of the Liver (EASL) registry group "Alpha-1 Liver".