1. Maastricht University, Maastricht, The Netherlands, and Unidad de Investigacion en Enfermedades Cronico Degenerativas; Guadalajara Jalisco Mexico
2. Amsterdam Rheumatology Center, Amsterdam, The Netherlands, and Hospital Garcia de Orta; Almada Portugal
3. Hospital Garcia de Orta, Almada, Portugal, and Atrium Medical Center; Heerlen The Netherlands
4. Leiden University Medical Center; Leiden The Netherlands
5. Cochin Hospital; Paris France
6. Ghent University Hospital; Ghent Belgium
7. Maastricht University; Maastricht The Netherlands