title: [Immunoassay for matrix metalloproteinase-9 in the tear film of patients with pseudoexfoliation syndrome - a pilot study].
abstract: BACKGROUND
  Matrix-metalloproteinases (MMPs) are proteolytic enzymes released by irritated epithelial cells of the ocular surface. It has been established that the subtype MMP-9 can serve as an inflammatory marker within the tear film. MMP-9 is also attributed to have an effect on the PEX-glaucoma development. Recently, a rapid immunoassay for detection of MMP-9 in the tear film was developed to estimate inflammatory extent during dry eye disease. The aim of this study was to analyse the MMP-9 concentration in tear film in PEX-syndrome. In addition, an assessment of the feasibility, reliability and readability of the test was done.
  
  
  METHODS
  We randomly selected 10 patients with PEX-syndrome and 10 healthy control patients and measured tear film MMP-9 of one eye with the RPS InflammaDry Detector™ (Rapid Pathogen Screening Inc., USA).
  
  
  RESULTS
  We detected increased levels of MMP-9 in tear film in PEX-syndrome. 80 % of the PEX-patients and 20 % of the controls showed a positive test result (>or= 40 ng/mL MMP-9) indicating a test specificity and sensitivity of 80 %. This corresponds approximately to the published values for the dry eye (sensitivity 87 %, specificity: 92 %). The performance of the test is simple. The patients tolerated the inclusion of the test strips well. However, it is difficult to estimate whether enough tear film was used and in many cases, the intensity of the "indicator line" was weak.
  
  
  CONCLUSIONS
  The rapid MMP-9-immunoassay is a novel, meaningful approach for the detection of inflammatory activity of the ocular surface. We have shown an up-regulation of the non-specific inflammatory marker MMP-9 in tear film in PEX-syndrome and suggest an association with a tear film disorder. However, an improvement in the estimation of the amount of collected tears and readability is desirable.
authors.affiliation: Augenheilkunde, Augenklinik am Wittenbergplatz, Berlin. nicole_zimmermann@msn.com
authors.forename: N
authors.initials: N
authors.lastname: Zimmermann
authors.forename: C
authors.initials: C
authors.lastname: Erb
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000032:analysis; D017889:Exfoliation Syndrome / Q000175:diagnosis* / Q000378:metabolism*; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000032:analysis*; D010865:Pilot Projects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013666:Tears / Q000737:chemistry*
chemical_list: D015415:Biomarkers; D020780:Matrix Metalloproteinase 9