[1] Hosp Infantil Univ Nino Jesus, Pediat Rheumatol Unit, Madrid, Spain
[2] Hosp Univ La Paz, Pediat Rheumatol Dept, Madrid, Spain
[3] Hosp Univ 12 Octubre, Pediat Rheumatol Dept, Madrid, Spain
[4] Hosp Univ Gregorio Maranon, Rheumatol Dept, Madrid, Spain
[5] Hosp Univ Fuenlabrada, Rheumatol Dept, Madrid, Spain
[6] Hosp Univ Ramon y Cajal, Rheumatol Dept, Madrid, Spain
[7] Hosp Univ Clin San Carlos, Rheumatol Dept, Martin Lagos S-N, Madrid 28040, Spain
[8] Hosp Univ Clin San Carlos, IDISSC, Martin Lagos S-N, Madrid 28040, Spain
[9] Univ Camilo Jose Cela, Hlth Sci Fac, Madrid, Spain