[1] Tampere Univ Hosp, Dept Internal Med, Tampere, Finland
[2] Tampere Univ Hosp, Dept Pediat, Tampere, Finland
[3] Finnish Red Cross & Blood Transfus Serv, Tissue Typing Lab, Helsinki, Finland
[4] Univ Tampere, Inst Med Sch & Med Technol, FIN-33101 Tampere, Finland