title: CA 19-9 ELISA test: a new method for studying mucus changes in tears.
abstract: OBJECTIVE
  This study investigated mucus changes in the tears in various eye conditions using impression cytology. The quantity of mucins was measured by enzyme linked immunosorbent assay (ELISA) using the tumour marker CA 19-9. This assay quantifies the sialylated Lewis(a) structure mainly associated with ocular mucins.
  
  
  METHODS
  Impression cytology was performed using a cellulose nitrate membrane, on 53 healthy patients, 50 glaucoma patients treated with beta blockers, 24 patients suffering from dry eye syndrome, and 45 contact lens wearers. The tear film glycoproteins were eluted and CA 19-9 was measured.
  
  
  RESULTS
  CA 19-9 content expressed as kilo units (kU) per microgram of tears was significantly decreased in dry eye syndrome (25.8 kU (SD 17.3)/microgram) (p < 0.05), glaucoma patients over 60 years (28.9 (19.5) kU/microgram) (p < 0.05), and contact lens wearers (28.4 kU (18)/microgram) (p < 0.05), when compared with healthy individuals (39.4 kU (22.2)/microgram).
  
  
  CONCLUSIONS
  Impression cytology can be regarded as a valuable method for obtaining samples of glycoconjugates of mucin. The decrease of sialylated chains observed with this method confirms the hypothesis that some quantitative changes in the tear film may be encountered in ocular surface disorders.
authors.affiliation: Department of Ophthalmology, CHU Dijon, France.
authors.forename: C
authors.initials: C
authors.lastname: Garcher
authors.forename: A
authors.initials: A
authors.lastname: Bron
authors.forename: C
authors.initials: C
authors.lastname: Baudouin
authors.forename: L
authors.initials: L
authors.lastname: Bildstein
authors.forename: J
authors.initials: J
authors.lastname: Bara
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D001706:Biopsy; D018395:CA-19-9 Antigen / Q000097:blood; D003261:Contact Lenses / Q000009:adverse effects; D015352:Dry Eye Syndromes / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D005455:Fluorescent Antibody Technique; D005901:Glaucoma / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013666:Tears / Q000737:chemistry*
chemical_list: D015415:Biomarkers; D018395:CA-19-9 Antigen