University of Thessaly - Department of Immunology & Histocompatibility, University of Thessaly - Department of Immunology & Histocompatibility, University of Thessaly - Department of Immunology & Histocompatibility, University of Thessaly - Laboratory of Hygiene and Epidemiology, University of Thessaly - Department of Immunology & Histocompatibility, University of Thessaly - Department of Immunology & Histocompatibility, University of Thessaly - Laboratory of Hygiene and Epidemiology, National Public Health Organization, Athens, University of Thessaly - Laboratory of Hygiene and Epidemiology, University of Thessaly - Department of Immunology & Histocompatibility, University of Thessaly - Department of Immunology & Histocompatibility, University of Thessaly - Laboratory of Hygiene and Epidemiology, - 4th Department of Internal Medicine, University of Freiburg - Department of Rheumatology and Clinical Immunology and University of Thessaly - Laboratory of Hygiene and Epidemiology