title: Tear levels and activity of matrix metalloproteinase (MMP)-1 and MMP-9 in vernal keratoconjunctivitis.
abstract: OBJECTIVE
  To study levels and activity of matrix metalloproteinase (MMP)-1 and -9 and their tissue inhibitor (TIMP-1) in tears of patients with vernal keratoconjunctivitis (VKC), with and without severe corneal damage.
  
  
  METHODS
  Tear samples were obtained from 16 patients with active VKC and 10 normal control subjects, after clinical evaluation and tear cytology. Tear levels of pro-MMP-1, pro-MMP-9, and TIMP-1 were measured by enzyme-linked immunosorbent assay (ELISA). Collagenase and gelatinase activity were measured in tears by MMP activity assays. Immunohistochemistry was performed on a fragment of superficial keratectomy from two vernal corneal ulcers.
  
  
  RESULTS
  Tear levels of pro-MMP-1 and pro-MMP-9 were significantly increased in patients with VKC compared with control subjects (P < 0.001). MMP-1/TIMP-1 and MMP-9/TIMP-1 molar ratios were significantly increased (P < 0.001) in VKC. MMP-1 and MMP-9 activities were significantly increased in VKC tears compared with control samples (P < 0.005). MMP-9 activity correlated significantly with corneal involvement and giant papillae formation. Immunohistochemistry showed positive staining for MMP-9, fibronectin, and eosinophil cationic protein (ECP) on the superficial corneal stroma of the ulcer bed, but no inflammatory cells.
  
  
  CONCLUSIONS
  Increased levels and activity of MMP-1 and -9 and an imbalance between MMPs and TIMP may be involved in the pathogenesis of VKC.
authors.affiliation: Department of Neuroscience, Ophthalmology and Ocular Inflammation Unit, University of Padua, Padua, Italy. andrea.leonardi@unipd.it
authors.forename: Andrea
authors.initials: A
authors.lastname: Leonardi
authors.forename: Paola
authors.initials: P
authors.lastname: Brun
authors.forename: Giovanni
authors.initials: G
authors.lastname: Abatangelo
authors.forename: Mario
authors.initials: M
authors.lastname: Plebani
authors.forename: Antonio G
authors.initials: AG
authors.lastname: Secchi
mesh_terms: D000293:Adolescent; D000328:Adult; D001706:Biopsy; D001798:Blood Proteins / Q000378:metabolism; D002648:Child; D003233:Conjunctivitis, Allergic / Q000201:enzymology* / Q000276:immunology / Q000473:pathology; D003315:Cornea / Q000201:enzymology; D003320:Corneal Ulcer / Q000201:enzymology / Q000473:pathology; D004797:Enzyme-Linked Immunosorbent Assay; D047091:Eosinophil Granule Proteins; D005260:Female; D005353:Fibronectins / Q000378:metabolism; D006801:Humans; D007124:Immunoenzyme Techniques; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D020781:Matrix Metalloproteinase 1 / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D012260:Ribonucleases; D013666:Tears / Q000201:enzymology*; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism
chemical_list: D001798:Blood Proteins; D047091:Eosinophil Granule Proteins; D005353:Fibronectins; D019715:Tissue Inhibitor of Metalloproteinase-1; D007073:Immunoglobulin E; D012260:Ribonucleases; D020780:Matrix Metalloproteinase 9; D020781:Matrix Metalloproteinase 1