Clovis A Silva1, Maria T Terreri2, Eloisa Bonfa3, Claudia Saad-Magalhães4. 1. Pediatric Rheumatology Unit, Children's Institute, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Av. Dr. Eneas Carvalho Aguiar, 647 - Cerqueira César, Sao Paulo, SP, 05403-000, Brazil. clovis.silva@hc.fm.usp.br. 2. Pediatric Rheumatology Unit, Universidade Federal de Sao Paulo, Sao Paulo, Brazil. 3. Rheumatology Division, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brazil. 4. Pediatric Rheumatology Division, Sao Paulo State University (UNESP), Botucatu, Sao Paulo, Brazil.