title: A flow cytometric study about the immunopathology of vernal keratoconjunctivitis.
abstract: BACKGROUND
  Vernal keratoconjunctivitis (VKC) is a bilateral seasonal conjunctival inflammation. Exact pathogenesis of the disease is unknown, but some evidences suggest TH lymphocyte-mediated immune reactions.
  
  
  OBJECTIVE
  The aim of this study was to investigate the role of the T lymphocyte and its subsets in the pathogenesis of VKC.
  
  
  METHODS
  We obtained tear samples from patients with VKC and normal volunteers during active (spring) and quiescent (winter) periods. The patients' records were also obtained for assessment of symptom scores. The percentages of CD4/29+, CD4/45RA+, CD4+, and CD8+ in tear samples were established by using flow cytometry, and the results of all three groups were compared with each other by using the Wilcoxon matched-pair signed-rank test and the Mann-Whitney U test.
  
  
  RESULTS
  The percentages of CD4/29+ and CD4+ cells in tears of patients with VKC increased significantly in the active period and decreased to normal levels in the quiescent stage. In contrast, the percentages of CD4/45RA+ and CD8+ cells in tears of patients with VKC did not show any significant change between spring and winter. The patients' symptoms were significantly lower in the quiescent period (winter) compared with the active stage (spring).
  
  
  CONCLUSIONS
  We propose that increased numbers of CD4+ and CD4/29+ cells in tears may be exacerbating the disease during the spring season.
authors.affiliation: Karadeniz Technical University, School of Medicine, Department of Ophthalmology, Trabzon, Turkey.
authors.forename: A M
authors.initials: AM
authors.lastname: Avunduk
authors.forename: M C
authors.initials: MC
authors.lastname: Avunduk
authors.forename: V
authors.initials: V
authors.lastname: Dayanir
authors.forename: Y
authors.initials: Y
authors.lastname: Tekelioglu
authors.forename: Y S
authors.initials: YS
authors.lastname: Dayioglu
mesh_terms: D000293:Adolescent; D000328:Adult; D015703:Antigens, CD / Q000276:immunology*; D015704:CD4 Antigens / Q000276:immunology; D002648:Child; D003233:Conjunctivitis, Allergic / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D008297:Male; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D015703:Antigens, CD; D015704:CD4 Antigens