title: Analysis of inflammatory cytokines in the tears of dry eye patients.
abstract: OBJECTIVE
  To determine the levels of 8 important cytokines and 1 chemokine in tears of patients with dry eye disease.
  
  
  METHODS
  Tear samples were collected from 7 patients with dry eye disease and 7 healthy volunteers, and impression cytology samples were collected from 3 of the dry eye patients and 3 of the normal controls. Tears were analyzed for the presence of 8 cytokines [interleukin (IL)-2, IL-4, IL-5, IL-6, IL-10, interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, IL-1beta] and 1 chemokine (IL-8). The cytokines and chemokine in each tear sample were measured using Invitrogen's Multiplex Bead Immunoassays. The impression cytology samples were analyzed for IL-1beta, IL-6, IL-8, and TNF-alpha mRNA expression using real-time reverse transcriptase polymerase chain reaction anlaysis.
  
  
  RESULTS
  All cytokines and the chemokine measured were significantly increased in the tears of dry eye patients as compared to normal controls. mRNA of all four markers was increased, and the fold increase correlated well with the fold increase of the cytokine concentration found in the tear samples.
  
  
  CONCLUSIONS
  Tears from dry eye patients contain significantly increased concentrations of cytokines that show correlation to severity of the disease. The upregulation of their respective genes in the conjunctiva suggests that the concentration increase is not the result of evaporative effects, but of overproduction. These findings suggest that cytokines may play an important role in dry eye disease and topical cytokine modulators may be explored as a therapeutic approach to dry eye disease.
authors.affiliation: Department of Ophthalmology, Mount Sinai School of Medicine, New York, NY 10029, USA.
authors.forename: Morgan L
authors.initials: ML
authors.lastname: Massingale
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Li
authors.forename: Maithreyi
authors.initials: M
authors.lastname: Vallabhajosyula
authors.forename: Dongmei
authors.initials: D
authors.lastname: Chen
authors.forename: Yi
authors.initials: Y
authors.lastname: Wei
authors.forename: Penny A
authors.initials: PA
authors.lastname: Asbell
mesh_terms: D000328:Adult; D000368:Aged; D015352:Dry Eye Syndromes / Q000145:classification / Q000378:metabolism*; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D007118:Immunoassay; D007371:Interferon-gamma / Q000378:metabolism*; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism*; D007378:Interleukins / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013666:Tears / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism*
chemical_list: D005136:Eye Proteins; D016209:Interleukin-8; D007378:Interleukins; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; C042434:tear proteins; D007371:Interferon-gamma