1 Department of Microbiology, Immunology and Transplantation, KU Leuven, and Department of Laboratory Medicine, University Hospitals Leuven, Leuven, Belgium xavier.bossuyt@uzleuven.be.
2 Schweizerischer Verband der Diagnostikindustrie, Bern, Switzerland.
3 Experimental Laboratory of Immunological and Rheumatologic Researches, Istituto Auxologico Italiano Istituto di Ricovero e Cura a Carattere Scientifico, Milano, Italy.