1. Systemic Autoimmune Diseases Research Unit, Specialties Hospital UMAE-CIBIOR, Mexican Social Security Institute, Puebla, México
2. Department of Rheumatology, Medicine School, Meritorious Autonomous University of Puebla, Puebla, Mexico
3. Department of Haematology, Specialties Hospital UMAE, Mexican Social Security Institute, Puebla, México
4. Coordination of Health Research, Mexican Social Security Institute, México
5. Department of Rheumatology, Hospital Central Dr Ignacio Morones Prieto, San Luis Potosí, México