title: In vivo behavior of NTBI revealed by automated quantification system.
abstract: Non-Tf-bound iron (NTBI), which appears in serum in iron overload, is thought to contribute to organ damage; the monitoring of serum NTBI levels may therefore be clinically useful in iron-overloaded patients. However, NTBI quantification methods remain complex, limiting their use in clinical practice. To overcome the technical difficulties often encountered, we recently developed a novel automated NTBI quantification system capable of measuring large numbers of samples. In the present study, we investigated the in vivo behavior of NTBI in human and animal serum using this newly established automated system. Average NTBI in healthy volunteers was 0.44 ± 0.076 μM (median 0.45 μM, range 0.28-0.66 μM), with no significant difference between sexes. Additionally, serum NTBI rapidly increased after iron loading, followed by a sudden disappearance. NTBI levels also decreased in inflammation. The results indicate that NTBI is a unique marker of iron metabolism, unlike other markers of iron metabolism, such as serum ferritin. Our new automated NTBI quantification method may help to reveal the clinical significance of NTBI and contribute to our understanding of iron overload.
authors.affiliation: Department of Oncology for Local Community Cooperation, Asahikawa Medical University Hospital, Asahikawa, Japan.|Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa, Hokkaido, 078-8510, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ito
authors.affiliation: Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa, Hokkaido, 078-8510, Japan. ikuta@asahikawa-med.ac.jp.
authors.forename: Katsuya
authors.initials: K
authors.lastname: Ikuta
authors.affiliation: Research and Development Department, Shino-Test Corporation, Sagamihara, Kanagawa, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kato
authors.affiliation: Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa, Hokkaido, 078-8510, Japan.
authors.forename: Addo
authors.initials: A
authors.lastname: Lynda
authors.affiliation: Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa, Hokkaido, 078-8510, Japan.
authors.forename: Kotoe
authors.initials: K
authors.lastname: Shibusa
authors.affiliation: Department of Medical Laboratory and Blood Center, Asahikawa Medical University Hospital, Asahikawa, Hokkaido, Japan.
authors.forename: Noriyasu
authors.initials: N
authors.lastname: Niizeki
authors.affiliation: Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa, Hokkaido, 078-8510, Japan.
authors.forename: Yasumichi
authors.initials: Y
authors.lastname: Toki
authors.affiliation: Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa, Hokkaido, 078-8510, Japan.
authors.forename: Mayumi
authors.initials: M
authors.lastname: Hatayama
authors.affiliation: Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa, Hokkaido, 078-8510, Japan.
authors.forename: Masayo
authors.initials: M
authors.lastname: Yamamoto
authors.affiliation: Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa, Hokkaido, 078-8510, Japan.
authors.forename: Motohiro
authors.initials: M
authors.lastname: Shindo
authors.affiliation: Research and Development Department, Shino-Test Corporation, Sagamihara, Kanagawa, Japan.
authors.forename: Naomi
authors.initials: N
authors.lastname: Iizuka
authors.affiliation: Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa, Hokkaido, 078-8510, Japan.|Department of Gastrointestinal Immunology and Regenerative Medicine, Asahikawa Medical University, 2-1-1-1, Midorigaoka-Higashi, Asahikawa, Hokkaido, 078-8510, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kohgo
authors.affiliation: Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, 2-1-1-1 Midorigaoka-Higashi, Asahikawa, Hokkaido, 078-8510, Japan.
authors.forename: Mikihiro
authors.initials: M
authors.lastname: Fujiya
mesh_terms: D000328:Adult; D000818:Animals; D057205:Automation, Laboratory / Q000295:instrumentation*; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood; D007501:Iron / Q000097:blood* / Q000378:metabolism; D019190:Iron Overload / Q000097:blood; D007700:Kinetics; D008297:Male; D012737:Sex Factors
chemical_list: D015415:Biomarkers; D007501:Iron
keywords: Automated quantification system; Inflammation; Iron overload; Non-transferrin bound iron (NTBI)