[1] Univ Gothenburg, Dept Rheumatol & Inflammat Res, SE-41346 Gothenburg, Sweden
[2] Univ Gothenburg, Sahlgrenska Acad, Dept Pediat, SE-41346 Gothenburg, Sweden
[3] Landspitali Univ Hosp, Childrens Hosp, Reykjavik, Iceland
[4] Landspitali Univ Hosp, Dept Immunol, Reykjavik, Iceland