1 J.J. Canoso, MD, Department of Medicine, ABC Medical Center, Mexico City, Mexico, and Division of Rheumatology, Tufts University School of Medicine, Boston, Massachusetts, USA; jcanoso@gmail.com.
2 M.A. Saavedra, MD, Department of Medicine, Specialties Hospital "Antonio Fraga Mouret," National Medical Center La Raza, and Postgraduate Division, National Autonomous University of Mexico, Mexico City, Mexico.
3 E. Naredo, MD, Department of Rheumatology, Bone and Joint Research Unit, Hospital Universitario Fundación Jiménez Díaz, IIS Fundación Jiménez Díaz, and Universidad Autónoma de Madrid, Madrid, Spain.