title: Study of a newly developed high-performance liquid chromatography analyser for glycosylated haemoglobin measurements in blood containing haemoglobin variants in the Japanese population.
abstract: BACKGROUND
  This study examined the new high-performance liquid chromatography analyser HLC-723GX (GX) and investigated its ability to both measure glycosylated haemoglobin (HbA1c) values and determine whether haemoglobin variants could cause interference with these measurements in the Japanese population.
  
  
  METHODS
  For the basic GX examination, the within- and between-run precision, linearity of measurements, correlation of HbA1c values with current systems and the interference of chemically modified haemoglobin were determined. GX interference caused by the haemoglobin variant was examined by analysing 39 clinical laboratory samples that contained haemoglobin variants.
  
  
  RESULTS
  Good within- and between-run precision were found, with the coefficients of variation at ≤1.0%. A wide range of HbA1c measurement values were confirmed, with the HbA1c values strongly correlated with the results of the currently used HLC-723G8 system. Chemically modified haemoglobins were prepared by adding glucose, sodium cyanate, acetaldehyde or acetylsalicylic acid to normal blood samples. None of these samples had any influence on the HbA1c values determined by GX. GX analysis showed haemoglobin variants that eluted after HbA0 and were similar to HbD, or HbS had HbA1c values that were close to those measured by boronate affinity chromatography and immunoassay. GX found lower HbA1c values in blood that contained HbE or haemoglobin variants, which elute before or at nearly the same time as HbA0.
  
  
  CONCLUSIONS
  GX is useful for the analysis of HbA1c samples that contain HbD, HbS, HbC and haemoglobin variants, even though the elution times are similar. However, a countermeasure is needed in order to avoid overlooking other haemoglobin variants in Japan.
authors.affiliation: Department of Clinical Laboratory, Nihon University Itabashi Hospital, Tokyo, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Miyashita
authors.affiliation: Department of Clinical Laboratory, Nihon University Itabashi Hospital, Tokyo, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Sugiyama
authors.affiliation: Department of Clinical Laboratory, Nihon University Itabashi Hospital, Tokyo, Japan Division of Laboratory Medicine, Department of Pathology and Microbiology, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Shuukoh
authors.initials: S
authors.lastname: Yamadate
authors.affiliation: Division of Laboratory Medicine, Department of Pathology and Microbiology, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Nagashima
authors.affiliation: Division of Laboratory Medicine, Department of Pathology and Microbiology, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Satomura
authors.affiliation: Department of Clinical Laboratory, Nihon University Itabashi Hospital, Tokyo, Japan Division of Laboratory Medicine, Department of Pathology and Microbiology, Nihon University School of Medicine, Tokyo, Japan nakayama.tomohiro@nihon-u.ac.jp.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Nakayama
mesh_terms: D016477:Artifacts; D044466:Asian People; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation* / Q000379:methods; D006442:Glycated Hemoglobin / Q000032:analysis* / Q000737:chemistry; D006444:Hemoglobin C / Q000031:analogs & derivatives / Q000032:analysis; D006446:Hemoglobin E / Q000031:analogs & derivatives / Q000032:analysis; D006451:Hemoglobin, Sickle / Q000031:analogs & derivatives / Q000032:analysis; D006455:Hemoglobins, Abnormal / Q000032:analysis; D006801:Humans
chemical_list: D006442:Glycated Hemoglobin; D006444:Hemoglobin C; D006446:Hemoglobin E; D006451:Hemoglobin, Sickle; D006455:Hemoglobins, Abnormal; C032271:glycated hemoglobin E; C517652:hemoglobin A1c protein, human; C024240:glycated hemoglobin C; C032270:glycated hemoglobin D; C024241:glycated hemoglobin S
keywords: HLC-723GX; HbA1c; haemoglobin variant; high-performance liquid chromatography