title: Gene Expression-Based Predictive Models of Graft Versus Host Disease-Associated Dry Eye.
abstract: OBJECTIVE
  To develop a predictive model based on inflammatory gene mRNA expression in conjunctival cells of graft versus host disease (GvHD)-associated dry eye (DE) patients, as well as to find meaningful correlations between gene signals and clinical signs.
  
  
  METHODS
  Twenty GvHD-DE patients and 14 healthy controls were recruited. Patients discontinued medications for 1 week before examination. Dry eye-related symptoms and signs were recorded, and conjunctival epithelial cells were collected by impression cytology after spending 20 minutes under standard conditions within a Controlled Environmental Research Laboratory. Gene expression of inflammatory molecules was determined by polymerase chain reaction, and the results were correlated with clinical signs. Shrinkage discriminant analysis, support vector machine, and k-nearest neighbor classifier methods were used to develop predictive models that were validated considering accuracy, calibration, and discriminant capability.
  
  
  RESULTS
  Out of the 84 genes analyzed, 34 showed significant differences in expression. IL-6, IL-9, CCL24, CCL18, IL-10, IFN-γ, and CCL2 were highly increased (>6-fold); 26 genes were moderately upregulated (2- to 6-fold), whereas EGFR was downregulated (2.63 fold) in GvHD-DE samples. A panel based on EGFR, IL-6, IL-9, and NAMPT had an area under the receiver operating characteristic curve of 0.994, a sensitivity of 100%, and a specificity of 92.9%. EGFR expression correlated negatively with ocular surface damage markers, while IL-6, IL-9, and NAMPT correlated positively with these tests.
  
  
  CONCLUSIONS
  EGFR, IL-6, IL-9, and NAMPT have the greatest potential as diagnostic biomarkers, with excellent sensitivity, specificity, and clinical relevance to the ocular surface status of GvHD.
authors.affiliation: Institute of Applied Ophthalmobiology (IOBA), University of Valladolid, Valladolid, Spain.
authors.forename: Lidia
authors.initials: L
authors.lastname: Cocho
authors.affiliation: Institute of Applied Ophthalmobiology (IOBA), University of Valladolid, Valladolid, Spain 2Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Spain.
authors.forename: Itziar
authors.initials: I
authors.lastname: Fernández
authors.affiliation: Institute of Applied Ophthalmobiology (IOBA), University of Valladolid, Valladolid, Spain 2Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Spain.
authors.forename: Margarita
authors.initials: M
authors.lastname: Calonge
authors.affiliation: Institute of Applied Ophthalmobiology (IOBA), University of Valladolid, Valladolid, Spain.
authors.forename: Verónica
authors.initials: V
authors.lastname: Martínez
authors.affiliation: Institute of Applied Ophthalmobiology (IOBA), University of Valladolid, Valladolid, Spain 2Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Spain.
authors.forename: María J
authors.initials: MJ
authors.lastname: González-García
authors.affiliation: Hematology Service, University Hospital, Instituto Biosanitario de Salamanca (IBSAL), University of Salamanca, Salamanca, Spain.
authors.forename: Dolores
authors.initials: D
authors.lastname: Caballero
authors.affiliation: Hematology Service, University Hospital, Instituto Biosanitario de Salamanca (IBSAL), University of Salamanca, Salamanca, Spain.
authors.forename: Lucía
authors.initials: L
authors.lastname: López-Corral
authors.affiliation: Institute of Applied Ophthalmobiology (IOBA), University of Valladolid, Valladolid, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: García-Vázquez
authors.affiliation: Hematology Service, University Hospital, Instituto Biosanitario de Salamanca (IBSAL), University of Salamanca, Salamanca, Spain.
authors.forename: Lourdes
authors.initials: L
authors.lastname: Vázquez
authors.affiliation: Allergan, Inc., Irvine, California, United States.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Stern
authors.affiliation: Institute of Applied Ophthalmobiology (IOBA), University of Valladolid, Valladolid, Spain 2Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Spain.
authors.forename: Amalia
authors.initials: A
authors.lastname: Enríquez-de-Salamanca
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000378:metabolism*; D003228:Conjunctiva / Q000378:metabolism; D016207:Cytokines / Q000235:genetics*; D015352:Dry Eye Syndromes / Q000175:diagnosis / Q000235:genetics*; D004847:Epithelial Cells / Q000378:metabolism; D066246:ErbB Receptors / Q000235:genetics; D005136:Eye Proteins / Q000235:genetics*; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology*; D006086:Graft vs Host Disease / Q000175:diagnosis / Q000235:genetics*; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics; D016906:Interleukin-9 / Q000235:genetics; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D054409:Nicotinamide Phosphoribosyltransferase / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D012372:ROC Curve; D060888:Real-Time Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires
chemical_list: D015415:Biomarkers; D016207:Cytokines; D005136:Eye Proteins; C508600:IL6 protein, human; C508607:IL9 protein, human; D015850:Interleukin-6; D016906:Interleukin-9; D012333:RNA, Messenger; D054409:Nicotinamide Phosphoribosyltransferase; C085455:nicotinamide phosphoribosyltransferase, human; C512478:EGFR protein, human; D066246:ErbB Receptors