1. Rheumatology Department, CHU Gabriel Montpied , 63000 Clermont-Ferrand , France
2. Service de Biologie, CHU Gabriel Montpied , 63000 Clermont-Ferrand , France
3. Service de Rhumatologie, Hospices Civils de Lyon , 69437 Lyon, Cedex 03 , France
4. Inserm UMR 1033 , 69437 Lyon, Cedex 03 , France