title: Simple quantitation for potential serum disease biomarker peptides, primarily identified by a peptidomics approach in the serum with hypertensive disorders of pregnancy.
abstract: BACKGROUND
  We previously reported peptide candidates of disease biomarkers for pregnancy-induced hypertension syndrome using a novel peptidomic analytical method, BLOTCHIP®-MS. The aim of this study was to establish a sandwich enzyme-linked immunosorbent assay system for quantitation of such peptides and to validate their usefulness as disease biomarkers of pregnancy-induced hypertension syndrome including gestational hypertension/pre-eclampsia.
  
  
  METHODS
  We focused on three peptide fragments, kininogen-1439-456 (PDA039), kininogen-1438-456 (PDA044) and cysteinyl α2-HS-glycoprotein341-367 (PDA071). Using polyclonal antibodies specific for each peptide, suitable conditions for the sandwich enzyme-linked immunosorbent assay system were investigated. The quantitative enzyme-linked immunosorbent assay values were confirmed by quantitative matrix assisted laser desorption/ionization time-of-flight MS analyses. Using the established enzyme-linked immunosorbent assay systems, serum samples from gestational hypertension/pre-eclampsia patients and paired serum samples from healthy pregnant females were analysed.
  
  
  RESULTS
  The optimum sandwich enzyme-linked immunosorbent assay conditions for PDA039/044 quantitation were developed. Quantitation of PDA071 by enzyme-linked immunosorbent assay failed, presumably due to issues with polyclonal antibody specificity for the native peptide. Bland-Altman plots showed a satisfactory correlation between the serum PDA039/044 concentration by enzyme-linked immunosorbent assay and that by quantitative MS analysis. Although the PDA044 concentration showed no significant change during pregnancy, including gestational hypertension/pre-eclampsia patients, the serum PDA039 concentration was significantly increased (P < 0.0001) in the patients.
  
  
  CONCLUSIONS
  The simple quantitation technology for PDA039 by enzyme-linked immunosorbent assay was established for the first time. PDA039 confirmed its clinical utility as a disease biomarker for gestational hypertension/pre-eclampsia by the enzyme-linked immunosorbent assay system using clinical samples. The information provided from the present study would be a new valuable addition in the field of gestational hypertension/pre-eclampsia research.
authors.affiliation: Institute for Environmental and Gender-Specific Medicine, Juntendo University Graduate School of Medicine, Chiba, Japan Department of Obstetrics and Gynecology, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Kensuke
authors.initials: K
authors.lastname: Hamamura
authors.affiliation: Membrane Protein and Ligand Analysis Center, Protosera Inc., Hyogo, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Nonaka
authors.affiliation: Department of Health Information Management, Yamagata Saisei Hospital, Yamagata, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ishikawa
authors.affiliation: Department of Obstetrics and Gynecology, Yamagata Saisei Hospital, Yamagata, Japan.
authors.forename: Michio
authors.initials: M
authors.lastname: Banzai
authors.affiliation: Institute for Environmental and Gender-Specific Medicine, Juntendo University Graduate School of Medicine, Chiba, Japan.
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Yanagida
authors.affiliation: Department of Obstetrics and Gynecology, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Michio
authors.initials: M
authors.lastname: Nojima
authors.affiliation: Department of Obstetrics and Gynecology, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Koyo
authors.initials: K
authors.lastname: Yoshida
authors.affiliation: Membrane Protein and Ligand Analysis Center, Protosera Inc., Hyogo, Japan.
authors.forename: Lyang-Ja
authors.initials: LJ
authors.lastname: Lee
authors.affiliation: Membrane Protein and Ligand Analysis Center, Protosera Inc., Hyogo, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Tanaka
authors.affiliation: Institute for Environmental and Gender-Specific Medicine, Juntendo University Graduate School of Medicine, Chiba, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Takamori
authors.affiliation: Department of Obstetrics and Gynecology, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Takeda
authors.affiliation: Institute for Environmental and Gender-Specific Medicine, Juntendo University Graduate School of Medicine, Chiba, Japan Department of Obstetrics and Gynecology, Juntendo University Graduate School of Medicine, Tokyo, Japan yaraki@juntendo.ac.jp.
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Araki
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D046110:Hypertension, Pregnancy-Induced / Q000097:blood* / Q000175:diagnosis; D010455:Peptides / Q000097:blood*; D011225:Pre-Eclampsia / Q000097:blood / Q000175:diagnosis; D011247:Pregnancy; D040901:Proteomics / Q000379:methods*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D010455:Peptides
keywords: Sandwich enzyme-linked immunosorbent assays; hypertensive disorders of pregnancy; peptidomics; serum biomarkers