[1] Univ Uppsala Hosp, Dept Internal Med, S-75185 Uppsala, Sweden
[2] Univ Uppsala Hosp, Dept Pathol, S-75185 Uppsala, Sweden
[3] Univ Uppsala Hosp, Dept Pediat, S-75185 Uppsala, Sweden
[4] Univ Bergen, Dept Biochem & Mol Biol, Bergen, Norway
[5] Univ Bergen, Dept Med B, Bergen, Norway
[6] Univ Helsinki, Hosp Children & Adolescents, Helsinki, Finland