1 Rheumatology Department, General Hospital of México, Dr. Eduardo Liceaga, Dr. Balmis 148. Colonia Doctores. Del. Cuauhtemoc, C.P. 06726, Mexico, Mexico.
2 Hospital Provincial de Rosario, Leandro N. Alem 1450, Rosario, Santa Fe, Argentina.
3 Faculty of Medicine, Rheumatology Department, Hospital General de México, Universidad Nacional Autonoma de México, Mexico, Mexico. [email protected].