[1] Hosp Sierrallana, Santander, Spain
[2] Hosp Univ Marques Valdecilla, Santander, Spain
[3] Natl Inst Geriatr Rheumatol & Rehabil, Dept Rheumatol, Warsaw, Poland
[4] Med Univ Warsaw, Dept Neurol, Warsaw, Poland
[5] Karolinska Univ Hosp, Stockholm, Sweden
[6] Karolinska Inst, Stockholm, Sweden
[7] Hosp Univ Marques Valdecilla, IDIVAL, Santander, Spain
[8] Karolinska Inst, Div Rheumatol, Dept Med, Stockholm, Sweden
[9] Karolinska Univ, Dept Gastroenterol Dermatotol Rhematol, Stockholm, Sweden