title: Epithelial marker expression in Salzmann nodular degeneration shows characteristics of limbal transient amplifying cells and alludes to an involvement of the epithelium in its pathogenesis.
abstract: OBJECTIVE
  To look at the epithelial nature of Salzmann nodular degeneration (SND) and its possible relation with the aetiology of the subepithelial collagen deposition.
  
  
  METHODS
  Histological slides of 28 patients with SND were analysed for limbal and central corneal epithelial markers. Expression pattern of these markers in the basal layer of the epithelium was analysed and compared to the expression pattern in central corneal and limbal epithelium. Statistical analysis was performed by means of analysis of variance.
  
  
  RESULTS
  Expression of the epithelial stem cell marker ABCG2 and p63 was low in SND. Expression of CK12, a marker for terminally differentiated epithelium, was low, as well. But, CK19 and Enolase-alpha expressions were significantly increased and resembled the expression pattern of transient amplifying cells (TAC) of the limbus.
  
  
  CONCLUSIONS
  The epithelium in SND shows similar characteristics as TAC of the limbus and seems to be metabolically more active than the differentiated central corneal epithelium. This could be related to the deposition of subepithelial collagen fibrils seen in SND and points out a possible involvement of the corneal epithelium in the aetiology of Salzmann nodular degeneration.
authors.affiliation: University Eye Hospital Freiburg, Freiburg, Germany. philipp.eberwein@uniklinik-freiburg.de
authors.forename: Philipp
authors.initials: P
authors.lastname: Eberwein
authors.forename: Sonja
authors.initials: S
authors.lastname: Hiss
authors.forename: Claudia
authors.initials: C
authors.lastname: Auw-Haedrich
authors.forename: Rainer
authors.initials: R
authors.lastname: Sundmacher
authors.forename: Katharina
authors.initials: K
authors.lastname: Hauer
authors.forename: Daniel
authors.initials: D
authors.lastname: Boehringer
authors.forename: Peter
authors.initials: P
authors.lastname: Meier
authors.forename: Thomas
authors.initials: T
authors.lastname: Reinhard
mesh_terms: D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D003317:Corneal Dystrophies, Hereditary / Q000209:etiology / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D019573:Epithelium, Corneal / Q000378:metabolism*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D007633:Keratins / Q000378:metabolism; D016850:Limbus Corneae / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000378:metabolism; D055815:Young Adult
chemical_list: C116614:ABCG2 protein, human; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D015415:Biomarkers; D014408:Biomarkers, Tumor; C081876:CKAP4 protein, human; D004268:DNA-Binding Proteins; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D025521:Tumor Suppressor Proteins; D007633:Keratins; C095157:ENO1 protein, human; D010751:Phosphopyruvate Hydratase