Department of Internal Medicine I, Martin-Luther-University of Halle-Wittenberg, Ernst-Grube-Straße 40, 06120 Halle, Germany. Electronic address: jens.walldorf@uk-halle.de. Department of Internal Medicine I, Martin-Luther-University of Halle-Wittenberg, Ernst-Grube-Straße 40, 06120 Halle, Germany.