1. Center of Bone Marrow Transplantation; Hospital of University of the Ryukyus; Nishihara Japan
2. Department of Pediatrics; Nagoya University Graduate School of Medicine; Nagoya Japan
3. Okinawa Prefectural Nanbu Medical Center and Children's Medical Center; Haebaru Japan
4. Department of Pediatrics, Faculty of Medicine; University of the Ryukyus; Nishihara Japan