1. Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria.
2. Vienna HIV and Liver Study Group, Vienna, Austria.
3. Division of Immunology, Allergy and Infectious Diseases, Department of Dermatology, Medical University of Vienna, Vienna, Austria.
4. Department of Internal Medicine I, University of Bonn, Bonn, Germany.
5. Division of Clinical Virology, Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria.