title: Aqueous Tear Deficiency Increases Conjunctival Interferon-γ (IFN-γ) Expression and Goblet Cell Loss.
abstract: OBJECTIVE
  To investigate the hypothesis that increased interferon-γ (IFN-γ) expression is associated with conjunctival goblet cell loss in subjects with tear dysfunction.
  
  
  METHODS
  Goblet cell density (GCD) was measured in impression cytology from the temporal bulbar conjunctiva, and gene expression was measured in cytology samples from the nasal bulbar conjunctiva obtained from 68 subjects, including normal control, meibomian gland disease (MGD), non-Sjögren syndrome (non-SSATD)-, and Sjögren syndrome (SSATD)-associated aqueous tear deficiency. Gene expression was evaluated by real-time PCR. Tear meniscus height (TMH) was measured by optical coherence tomography. Fluorescein and lissamine green dye staining evaluated corneal and conjunctival disease, respectively. Between-group mean differences and correlation coefficients were calculated.
  
  
  RESULTS
  Compared to control, IFN-γ expression was significantly higher in both ATD groups, and its receptor was higher in SSATD. Expression of IL-13 and its receptor was similar in all groups. Goblet cell density was lower in the SSATD group; expression of MUC5AC mucin was lower and cornified envelope precursor small proline-rich region (SPRR)-2G higher in both ATD groups. Interferon-γ transcript number was inversely correlated with GCD (r = -0.37, P < 0.04) and TMH (r = -0.37, P = 0.02), and directly correlated with lissamine green staining (r = 0.51, P < 0.001) and SPRR-2G expression (r = 0.32, P < 0.05).
  
  
  CONCLUSIONS
  Interferon-γ expression in the conjunctiva was higher in aqueous deficiency and correlated with goblet cell loss and severity of conjunctival disease. These results support findings of animal and culture studies showing that IFN-γ reduces conjunctival goblet cell number and mucin production.
authors.affiliation: Ocular Surface Center Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States.
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Pflugfelder
authors.affiliation: Ocular Surface Center Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States.
authors.forename: Cintia S
authors.initials: CS
authors.lastname: De Paiva
authors.affiliation: Ocular Surface Center Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States.
authors.forename: Quianta L
authors.initials: QL
authors.lastname: Moore
authors.affiliation: Ocular Surface Center Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States.
authors.forename: Eugene A
authors.initials: EA
authors.lastname: Volpe
authors.affiliation: Ocular Surface Center Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States.
authors.forename: De-Quan
authors.initials: DQ
authors.lastname: Li
authors.affiliation: Ocular Surface Center Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States 2Department of Ophthalmology, Erciyes University School of Medicine, Kayseri, Turkey.
authors.forename: Koray
authors.initials: K
authors.lastname: Gumus
authors.affiliation: Ocular Surface Center Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States.
authors.forename: Mahira L
authors.initials: ML
authors.lastname: Zaheer
authors.affiliation: Ocular Surface Center Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, United States.
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Corrales
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002478:Cells, Cultured; D003228:Conjunctiva / Q000378:metabolism* / Q000473:pathology; D015352:Dry Eye Syndromes / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D005786:Gene Expression Regulation; D020397:Goblet Cells / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D012313:RNA / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D013666:Tears / Q000378:metabolism*; D055815:Young Adult
chemical_list: D012313:RNA; D007371:Interferon-gamma