title: Validation of an autotaxin enzyme immunoassay in human serum samples and its application to hypoalbuminemia differentiation.
abstract: BACKGROUND
  Autotaxin (ATX), a tumor cell motility-stimulating factor, regulates the blood concentrations of lysophosphatidic acid (LPA), an important and multi-functional bioactive lipid, through its lysophospholipase D activity (lysoPLD). The introduction of ATX measurements into clinical laboratory testing is urgently needed.
  
  
  METHODS
  Anti-human ATX monoclonal antibodies were produced by immunization of recombinant human ATX expressed in a baculovirus system. An immunoassay for the quantitative determination of ATX was established, and human serum samples were assayed.
  
  
  RESULTS
  The within-run and between-run precision, interference, detection limit, and linearity studies were satisfactory. The central 95 percentile reference interval for the serum ATX antigen concentration in healthy subjects was 0.468-1.134 mg/l (n=120) and was strongly correlated with the serum lysoPLD activity. The ATX concentration was significantly (p<0.001) higher in women (0.625-1.323 mg/l) than in men (0.438-0.914 mg/l). The serum ATX concentrations were increased in patients with chronic liver diseases and decreased in postoperative prostate cancer patients but were not altered in nephrosis patients. Thus, serum ATX antigen concentrations could be used to discriminate these hypoalbuminemia conditions.
  
  
  CONCLUSIONS
  The present ATX antigen assay may be useful for clinical laboratory testing.
authors.affiliation: Department of Clinical Laboratory, The University of Tokyo Hospital, Tokyo, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Nakamura
authors.forename: Koji
authors.initials: K
authors.lastname: Igarashi
authors.forename: Kazufumi
authors.initials: K
authors.lastname: Ide
authors.forename: Ryunosuke
authors.initials: R
authors.lastname: Ohkawa
authors.forename: Shigeo
authors.initials: S
authors.lastname: Okubo
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Yokota
authors.forename: Akiko
authors.initials: A
authors.lastname: Masuda
authors.forename: Noriko
authors.initials: N
authors.lastname: Oshima
authors.forename: Takumi
authors.initials: T
authors.lastname: Takeuchi
authors.forename: Masaomi
authors.initials: M
authors.lastname: Nangaku
authors.forename: Shinichi
authors.initials: S
authors.lastname: Okudaira
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Arai
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ikeda
authors.forename: Junken
authors.initials: J
authors.lastname: Aoki
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Yatomi
mesh_terms: D000941:Antigens / Q000097:blood; D002908:Chronic Disease; D005260:Female; D006262:Health; D006801:Humans; D034141:Hypoalbuminemia / Q000097:blood* / Q000175:diagnosis*; D007124:Immunoenzyme Techniques / Q000379:methods*; D008107:Liver Diseases / Q000378:metabolism; D008297:Male; D009097:Multienzyme Complexes / Q000097:blood* / Q000235:genetics / Q000302:isolation & purification; D009401:Nephrosis / Q000097:blood; D043264:Phosphodiesterase I / Q000097:blood* / Q000235:genetics / Q000302:isolation & purification; D010739:Phospholipase D / Q000378:metabolism; D010727:Phosphoric Diester Hydrolases; D011471:Prostatic Neoplasms / Q000097:blood / Q000601:surgery; D011755:Pyrophosphatases / Q000097:blood* / Q000235:genetics / Q000302:isolation & purification; D000099189:Lysophospholipase D
chemical_list: D000941:Antigens; D009097:Multienzyme Complexes; D043264:Phosphodiesterase I; D010739:Phospholipase D; D010727:Phosphoric Diester Hydrolases; D011755:Pyrophosphatases; D000099189:Lysophospholipase D