1 Department of Internal Medicine, Division of Rheumatology, Maastricht University Medical Center, Maastricht, the Netherlands. Electronic address: mathijs.willemsen@mumc.nl.
2 Department of Microbiology, Immunology and Transplantation, Allergy and Clinical Immunology Research Group, KU Leuven, Leuven, Belgium.
3 Department of Microbiology, Immunology and Transplantation, Allergy and Clinical Immunology Research Group, KU Leuven, Leuven, Belgium; Department of General Internal Medicine, Division of Allergy and Clinical Immunology, University Hospitals Leuven, Leuven, Belgium.
4 Department of Internal Medicine, Division of Rheumatology, Maastricht University Medical Center, Maastricht, the Netherlands.