1. Hamburg Center for Paediatric and Adolescent Rheumatology, Am Schön Klinik Eilbek, Hamburg, Germany.
2. German Rheumatism Research Center, Berlin, Germany.
3. Hamburg Center for Paediatric and Adolescent Rheumatology, Am Schön Klinik Eilbek, Hamburg, Germany. foeldvari@t-online.de