title: Epiretinal membrane inflammatory cell density might reflect the activity of proliferative diabetic retinopathy.
abstract: OBJECTIVE
  Diabetic retinopathy (DR) has features of chronic low-grade inflammation. The purpose of our study was to investigate whether the presence of inflammatory cells in fibrovascular membranes (FVMs) from patients with proliferative diabetic retinopathy (PDR) is associated with the activity of PDR and visual acuity improvement after vitreoretinal surgery.
  
  
  METHODS
  Forty FVMs from 40 patients with PDR were obtained during vitrectomy, prepared by using the agar sandwich method, and examined using light microscope and immunohistochemistry methods to define the presence and density of inflammatory cells: CD45+ cells (leukocytes), CD4+ cells (T helper lymphocytes), CD8+ cells (T cytotoxic lymphocytes), CD19+ cells (B lymphocytes), and CD14+ cells (monocytes/macrophages). For each FVM, the inflammatory cell density defined as numerical areal density was calculated. The number of vessels was defined as the volume density of vessels.
  
  
  RESULTS
  Among 40 patients with PDR, 33 patients had active PDR and 7 quiescent PDR. Significant differences in cell densities for CD4+, CD8+, and CD19+ cells were observed between patients with active and quiescent PDR. B lymphocytes were present in membranes of active PDR only. No correlation was observed between numerical areal density of inflammatory cells and the volume density of vessels. No association was found between visual acuity improvement after surgery and cell densities.
  
  
  CONCLUSIONS
  Lymphocyte infiltration of FVMs might be associated with the activity of retinopathy but not with visual acuity improvement after surgery.
authors.affiliation: Eye Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia.
authors.forename: Mojca
authors.initials: M
authors.lastname: Urbančič
authors.affiliation: Eye Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia.
authors.forename: Špela
authors.initials: Š
authors.lastname: Štunf
authors.affiliation: Institute of Histology and Embryology, Medical Faculty, University of Ljubljana, Ljubljana, Slovenia.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Milutinović Živin
authors.affiliation: Institute of Histology and Embryology, Medical Faculty, University of Ljubljana, Ljubljana, Slovenia.
authors.forename: Daniel
authors.initials: D
authors.lastname: Petrovič
authors.affiliation: Eye Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia.
authors.forename: Mojca
authors.initials: M
authors.lastname: GlobočnikPetrovič
mesh_terms: D002452:Cell Count; D003930:Diabetic Retinopathy / Q000150:complications* / Q000473:pathology; D018450:Disease Progression; D019773:Epiretinal Membrane / Q000209:etiology / Q000473:pathology* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D007249:Inflammation / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D014821:Vitrectomy
keywords: activity of retinopathy; fibrovascular membranes; inflammatory cells; lymphocyte infiltration; prognosis; proliferative diabetic retinopathy; visual acuity; vitreoretinal surgery