title: Cell types of secondary cataract: an immunohistochemical analysis with antibodies to cytoskeletal elements and macrophages.
abstract: BACKGROUND
  The study was carried out to identify cell types of secondary cataract after extracapsular cataract extraction and implantation of an intraocular lens.
  
  
  METHODS
  Twenty-five formalin-fixed, paraffin-embedded pseudophakic human eyes with secondary cataract, obtained at autopsy, were studied and compared to a specimen from an anterior subcapsular cataract with a panel of six monoclonal antibodies (MAbs, to vimentin, cytokeratin (CK) 8 and 18, desmin, alpha-smooth muscle actin, and the CD68 epitope of macrophages by the avidin-biotinylated peroxidase complex (ABC) method.
  
  
  RESULTS
  MAb Vim 3B4 to vimentin immunolabeled spindle-shaped cells in 16 of 17 central plaques of secondary cataract as well as cells in all 16 Soemmering's ring cataracts. Spindle-shaped cells reacted with MAb CAM 5.2 to CK 8 in 13 of 18 eyes, but only one specimen was labeled with MAb CY-90 to CK 18. No immunoreaction was seen with MAb D33 to desmin, whereas MAb 1A4 to alpha-smooth muscle actin immunolabeled spindle-shaped cells in 15 of 18 plaques of secondary cataract. Macrophages were seen with MAb PG-M1 in 13 of 19 secondary cataracts. In the anterior subcapsular cataract, spindle-shaped cells under a wrinkled but otherwise intact capsule reacted with MAb Vim 3B4 to vimentin, MAb CAM 5.2 to CK 8, and MAb 1A4 to alpha-smooth muscle actin.
  
  
  CONCLUSIONS
  Spindle-shaped cells in secondary and anterior subcapsular cataracts react with antibodies to vimentin, CK 8 and alpha-smooth muscle actin, suggesting them to be metaplastic epithelial cells that derive from the lens epithelium. alpha-Smooth muscle actin persists in them at least 10 years postoperatively, but CK 8 starts to disappear after 3 years. Macrophages are one possible modulator of this transdifferentiation.
authors.affiliation: Department of Ophthalmology, Helsinki University Central Hospital, Finland msuusita@cc.helsinki.fi
authors.forename: M
authors.initials: M
authors.lastname: Uusitalo
authors.forename: T
authors.initials: T
authors.lastname: Kivelä
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000378:metabolism*; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism*; D002386:Cataract / Q000209:etiology / Q000378:metabolism / Q000473:pathology*; D002387:Cataract Extraction / Q000009:adverse effects; D002448:Cell Adhesion; D003598:Cytoskeletal Proteins / Q000276:immunology / Q000378:metabolism*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007124:Immunoenzyme Techniques; D007903:Lens Capsule, Crystalline / Q000378:metabolism / Q000473:pathology*; D007910:Lenses, Intraocular / Q000009:adverse effects; D008264:Macrophages / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D000097382:CD68 Molecule
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D003598:Cytoskeletal Proteins; C067980:CD68 antigen, human; D000097382:CD68 Molecule