title: A New Enzyme Immunoassay for the Quantitative Determination of Classical Autotaxins (ATXα, ATXβ, and ATXγ) and Novel Autotaxins (ATXδ and ATXε).
abstract: BACKGROUND
  Autotaxin (ATX) is a secreted enzyme that converts lysophosphatidylcholine to lysophosphatidic acid, a potent bioactive lipid mediator, through its lysophospholipase D activity. Although five alternative splicing isoforms of ATX have been identified as ATXα, ATXβ, ATXγ, ATXδ, and ATXε and the expression patterns of each isoform differ among several tissues, the clinical significance of each isoform remains to be elucidated.
  
  
  METHODS
  Anti-ATXβ and anti-ATXδ monoclonal antibodies were produced by immunization with recombinant human ATXβ and ATXδ expressed using a baculovirus system, respectively. We then developed enzyme immunoassays to measure the serum concentrations of "classical ATX" (ATXα, ATXβ, and ATXγ) and "novel ATX" (ATXδ and ATXε) antigens and evaluated the usefulness of these assays using human serum samples.
  
  
  RESULTS
  The with-run and between-run precision, interference, detection limit, and linearity studies for the present assay were well validated. In healthy subjects, the serum concentrations of classical ATX and novel ATX were significantly (P < 0.01) higher in women than in men, while the ratios of classical ATX or novel ATX to total ATX were not different between women and men. The concentrations of both classical ATX and novel ATX in normal pregnant subjects and patients with chronic liver diseases or follicular lymphoma were significantly higher than those in healthy subjects, while the ratio of both ATX isoforms to total ATX did not vary among these groups.
  
  
  CONCLUSIONS
  We have developed a new enzyme immunoassay to determine the concentrations of classical ATX and novel ATX in human serum. These assays may be helpful for elucidating the distinct functional roles of each ATX isoform, which are largely unknown at present.
authors.affiliation: Department of Clinical Laboratory, The University of Tokyo Hospital, Tokyo, Japan; CREST, Japan Science and Technology Corporation (JST), Saitama, Japan; Department of Medical Technology, Kagawa Prefectural University of Health Sciences, Kagawa, Japan.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Tokuhara
authors.affiliation: CREST, Japan Science and Technology Corporation (JST), Saitama, Japan; Department of Clinical Laboratory Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Kurano
authors.affiliation: Bioscience Division, Reagent Development Department, AIA Research Group, TOSOH Corporation, Kanagawa, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Shimamoto
authors.affiliation: Bioscience Division, Reagent Development Department, AIA Research Group, TOSOH Corporation, Kanagawa, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Igarashi
authors.affiliation: Department of Clinical Laboratory, The University of Tokyo Hospital, Tokyo, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Nojiri
authors.affiliation: Department of Clinical Laboratory, The University of Tokyo Hospital, Tokyo, Japan.
authors.forename: Tamaki
authors.initials: T
authors.lastname: Kobayashi
authors.affiliation: CREST, Japan Science and Technology Corporation (JST), Saitama, Japan; Department of Clinical Laboratory Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Masuda
authors.affiliation: CREST, Japan Science and Technology Corporation (JST), Saitama, Japan; Department of Clinical Laboratory Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ikeda
authors.affiliation: Department of Obstetrics and Gynecology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nagamatsu
authors.affiliation: Department of Obstetrics and Gynecology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Fujii
authors.affiliation: CREST, Japan Science and Technology Corporation (JST), Saitama, Japan; Laboratory of Molecular and Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Miyagi, Japan.
authors.forename: Junken
authors.initials: J
authors.lastname: Aoki
authors.affiliation: Department of Clinical Laboratory, The University of Tokyo Hospital, Tokyo, Japan; CREST, Japan Science and Technology Corporation (JST), Saitama, Japan; Department of Clinical Laboratory Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Yatomi
mesh_terms: D000328:Adult; D000911:Antibodies, Monoclonal / Q000276:immunology; D002908:Chronic Disease; D003920:Diabetes Mellitus / Q000097:blood / Q000201:enzymology; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods*; D057230:Limit of Detection; D008107:Liver Diseases / Q000097:blood / Q000201:enzymology; D008224:Lymphoma, Follicular / Q000097:blood / Q000201:enzymology; D008297:Male; D010727:Phosphoric Diester Hydrolases / Q000097:blood* / Q000276:immunology; D011247:Pregnancy; D020033:Protein Isoforms / Q000097:blood / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D020033:Protein Isoforms; D010727:Phosphoric Diester Hydrolases