[1] Fukushima Med Univ Hosp, Div Blood Transfus & Transplant Immunol, Fukushima 9601295, Japan
[2] Tottori Univ, Fac Med, Dept Pediat, Tottori 680, Japan
[3] Tottori Univ, Fac Med, Dept Virol, Tottori 680, Japan
[4] Dokkyo Med Univ, Sch Med, Dept Obstet & Gynecol, Mibu, Tochigi, Japan
[5] Yokohama E Hosp, Childrens Ctr Hlth & Dev, Kanagawa, Japan
[6] Osaka Prefectural Gen Hosp, Dept Pediat, Osaka, Japan
[7] Univ Tsukuba, Sch Med, Dept Child Hlth, Tsukuba, Ibaraki, Japan
[8] Okayama Univ, Grad Sch Med, Dept Pediat, Okayama, Japan
[9] Nagoya City Univ, Sch Med, Dept Pediat, Aichi, Japan
[10] Kurume Univ, Sch Med, Dept Pediat & Child Hlth, Fukuoka, Japan