1. Department of Allergy and Rheumatology, Chiba Children’s Hospital , Chiba, Japan
2. Department of General Medical Science, Graduate School of Medicine, Chiba University , Chiba, Chiba, Japan
3. Department of Pediatrics, Eastern Chiba Medical Center , Togane, Chiba, Japan
4. Division of Gastroenterology, Hepatology, and Nutrition, Cincinnati Children’s Hospital Medical Center , Cincinnati, OH, USA
5. Department of Emergency and General Pediatrics, Chiba Children’s Hospital , Chiba, Japan
6. Department of Pediatric Surgery, Chiba Children’s Hospital , Chiba, Japan