1. Hospital Ángeles del Pedregal, Mexico City, Mexico
2. Musculoskeletal Ultrasound Laboratory, Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Mexico City, Mexico
3. Department of Immunology, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico
4. Department of Rheumatology, The American British Cowdray Hospital, Mexico City, Mexico
5. Department of Rheumatology, General Hospital No. 8, Instituto Mexicano del Seguro Social, Mexico City, Mexico
6. Internal Medicine, Hospital Faro del Mayab/Christus Muguerza, Mérida Yucatán, Mexico
7. Department of Rheumatology, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico