title: Non-transferrin-bound iron assay system utilizing a conventional automated analyzer.
abstract: BACKGROUND
  Iron is an essential metal in the body, but its excessive accumulation causes damage in various organs through free radical production. Iron homeostasis is therefore tightly regulated. However, when iron balance collapses, such as in prolonged transfusion, transferrin (Tf) is fully saturated and non-Tf-bound iron (NTBI) appears in the serum. Monitoring serum NTBI levels is therefore crucial in the assessment of the clinical status of patients with iron overload, since NTBI is associated with cellular and organ damage. Several methods for NTBI determination have been reported, but these are extremely complicated and very few laboratories can quantify NTBI at present.
  
  
  METHODS
  We established a novel assay system utilizing automated analyzers that are widely used in clinical laboratories for diagnostic testing. In this assay, NTBI is chelated by nitrilotriacetic acid (NTA), after which the iron is reduced and transferred to nitroso-PSAP, a chromogen.
  
  
  RESULTS
  The assay shows excellent linearity, reproducibility, and compatibility with HPLC, one of the most reliable conventional methods for NTBI quantification.
  
  
  CONCLUSIONS
  Our novel method for NTBI measurement is high-throughput and may be a useful and powerful tool in the study of the physiological and clinical importance of NTBI.
authors: Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Asahikawa, Hokkaido, Japan.
authors: Satoshi
authors: S
authors: Ito
authors: Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Asahikawa, Hokkaido, Japan. Electronic address: ikuta@asahikawa-med.ac.jp.
authors: Katsuya
authors: K
authors: Ikuta
authors: Research and Development Department, Shino-Test Corporation, Sagamihara, Kanagawa, Japan.
authors: Daisuke
authors: D
authors: Kato
authors: Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Asahikawa, Hokkaido, Japan.
authors: Kotoe
authors: K
authors: Shibusa
authors: Department of Medical Laboratory and Blood Center, Asahikawa Medical University Hospital, Asahikawa, Hokkaido, Japan.
authors: Noriyasu
authors: N
authors: Niizeki
authors: Department of Gastrointestinal Immunology and Regenerative Medicine, Asahikawa Medical University, Asahikawa, Hokkaido, Japan.
authors: Hiroki
authors: H
authors: Tanaka
authors: Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Asahikawa, Hokkaido, Japan.
authors: Lynda
authors: L
authors: Addo
authors: Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Asahikawa, Hokkaido, Japan.
authors: Yasumichi
authors: Y
authors: Toki
authors: Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Asahikawa, Hokkaido, Japan.
authors: Mayumi
authors: M
authors: Hatayama
authors: Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Asahikawa, Hokkaido, Japan.
authors: Junki
authors: J
authors: Inamura
authors: Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Asahikawa, Hokkaido, Japan.
authors: Motohiro
authors: M
authors: Shindo
authors: Department of Gastrointestinal Immunology and Regenerative Medicine, Asahikawa Medical University, Asahikawa, Hokkaido, Japan.
authors: Katsunori
authors: K
authors: Sasaki
authors: Research and Development Department, Shino-Test Corporation, Sagamihara, Kanagawa, Japan.
authors: Naomi
authors: N
authors: Iizuka
authors: Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Asahikawa, Hokkaido, Japan.
authors: Mikihiro
authors: M
authors: Fujiya
authors: Oncology Center, Asahikawa Medical University Hospital, Asahikawa, Hokkaido, Japan.
authors: Yoshihiro
authors: Y
authors: Torimoto
authors: Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, Asahikawa, Hokkaido, Japan.
authors: Yutaka
authors: Y
authors: Kohgo
mesh_terms: D000818:Animals; D057205:Automation, Laboratory / Q000379:methods / Q000592:standards; D002417:Cattle; D002623:Chemistry Techniques, Analytical / Q000379:methods* / Q000592:standards; D002851:Chromatography, High Pressure Liquid / Q000379:methods / Q000592:standards; D006801:Humans; D007501:Iron / Q000097:blood*; D014168:Transferrin / Q000032:analysis*
chemical_list: D014168:Transferrin; D007501:Iron
keywords: Automated analyzer; Iron overload; Iron toxicity; Nitroso-PSAP; Non-transferrin-bound iron; Quantification