1. Systemic Autoimmune Diseases Research Unit, IMSS, Puebla, México
2. Department of Rheumatology and Immunology, Benemérita Universidad Autónoma de Puebla, Puebla, México
3. Department of Health Services Administration, Benemérita Universidad Autónoma de Puebla, Puebla, México
4. Education Department, IMSS, Puebla, México