title: Differential cell proliferation, apoptosis, and immune response in healthy and evaporative-type dry eye conjunctival epithelia.
abstract: OBJECTIVE
  To assess cell viability and cell cycle kinetics of the conjunctival epithelium and to identify intraepithelial lymphocyte (IEL) subsets in patients with evaporative-type dry eye disease (ev-DED) caused by meibomian gland dysfunction and in healthy subjects. The effect of topical treatment and correlations between clinical symptoms and signs and epithelial and immune variables were also determined.
  
  
  METHODS
  Inferior fornix and tarsal conjunctival cells were collected by brush cytology (BC) from patients with mild to moderate ev-DED (n = 23) before and after 2 months of treatment that included lid hygiene, artificial tears, and a 3-week course of topical unpreserved steroids. Healthy subjects (n = 17) served as controls. Two symptom questionnaires were self-answered, and multiple DED-related clinical tests were performed. Epithelial or immune lineage, IEL subtypes, cell viability, apoptosis, and cell cycle stage of the BC-recovered cells were determined by flow cytometry.
  
  
  RESULTS
  Conjunctival cell viability was dramatically decreased in ev-DED patients compared with controls. For both groups, two different cell populations, differentiated by cell size and complexity, were present in the apoptosis assay. After 2 months of treatment, 87% of subjects subjectively improved, CD8 cells increased, and CD4 cells and the CD4/CD8 ratio significantly decreased. The pretreatment and posttreatment proliferative capacity of the conjunctival epithelium was significantly lower in ev-DED patients than in healthy controls.
  
  
  CONCLUSIONS
  The viability and proliferative capacity of ev-DED patient conjunctival cells were reduced, suggesting a potential role for these parameters as disease biomarkers.
authors.affiliation: Ocular Surface Group, Institute for Applied Ophthalmobiology, Valladolid, Spain.
authors.forename: Roberto
authors.initials: R
authors.lastname: Reinoso
authors.forename: Margarita
authors.initials: M
authors.lastname: Calonge
authors.forename: Evangelina
authors.initials: E
authors.lastname: Castellanos
authors.forename: Mario
authors.initials: M
authors.lastname: Martino
authors.forename: Itziar
authors.initials: I
authors.lastname: Fernández
authors.forename: Michael E
authors.initials: ME
authors.lastname: Stern
authors.forename: Alfredo
authors.initials: A
authors.lastname: Corell
mesh_terms: D000328:Adult; D000368:Aged; D017209:Apoptosis; D002453:Cell Cycle; D049109:Cell Proliferation; D003228:Conjunctiva / Q000276:immunology / Q000473:pathology*; D015352:Dry Eye Syndromes / Q000276:immunology / Q000473:pathology*; D004847:Epithelial Cells / Q000276:immunology / Q000473:pathology*; D005260:Female; D005434:Flow Cytometry; D005500:Follow-Up Studies; D006801:Humans; D007111:Immunity, Cellular; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies