title: Endothelial cell changes as an indicator for upcoming allograft rejection following descemet membrane endothelial keratoplasty.
abstract: OBJECTIVE
  To report early, specific changes in donor endothelial cell morphology as a predictor of an upcoming allograft rejection after Descemet membrane endothelial keratoplasty (DMEK).
  
  
  METHODS
  Retrospective, observational case series.
  
  
  METHODS
  Out of a cohort of 500 eyes that underwent DMEK at a tertiary referral center, 7 eyes developed typical clinical signs of an allograft rejection. Specular microscopy images before, during, and after the rejection episode were analyzed and compared with a case-control group of 49 asymptomatic DMEK eyes that matched baseline characteristics of the rejection group. Endothelial cell morphology was evaluated by subjective scoring (range 1-5) in a masked fashion as well as by an objective comparison of endothelial cell density, cell size, coefficient of variation, and hexagonality in rejection vs control eyes.
  
  
  RESULTS
  Subjective scores (median) were higher before and after rejection (2.5 and 5, respectively) than in the DMEK control group (2.0 and 2.5, respectively) at comparable time points (P = .0230 and P = .0005, respectively). Endothelial cell density also differed before (P = .0106) and after rejection (P = .0240), while hexagonality differed before (P = .0499) but not after rejection (P = .1767).
  
  
  CONCLUSIONS
  Our study suggests that allograft rejection may not be an acute event, but rather a slow-onset immune response. Early, specific changes in endothelial cell morphology were found to "announce" an upcoming allograft rejection. If so, monitoring donor endothelium after DMEK or other forms of keratoplasty may be used to anticipate a rejection episode and/or to prevent an allograft rejection from clinically manifesting itself.
authors.affiliation: Netherlands Institute for Innovative Ocular Surgery, Rotterdam, Netherlands; Melles Cornea Clinic Rotterdam, Rotterdam, Netherlands.
authors.forename: Claire
authors.initials: C
authors.lastname: Monnereau
authors.affiliation: Netherlands Institute for Innovative Ocular Surgery, Rotterdam, Netherlands; Melles Cornea Clinic Rotterdam, Rotterdam, Netherlands; Amnitrans EyeBank Rotterdam, Rotterdam, Netherlands.
authors.forename: Marieke
authors.initials: M
authors.lastname: Bruinsma
authors.affiliation: Netherlands Institute for Innovative Ocular Surgery, Rotterdam, Netherlands; Melles Cornea Clinic Rotterdam, Rotterdam, Netherlands; Amnitrans EyeBank Rotterdam, Rotterdam, Netherlands.
authors.forename: Lisanne
authors.initials: L
authors.lastname: Ham
authors.affiliation: Netherlands Institute for Innovative Ocular Surgery, Rotterdam, Netherlands; Melles Cornea Clinic Rotterdam, Rotterdam, Netherlands.
authors.forename: Lamis
authors.initials: L
authors.lastname: Baydoun
authors.affiliation: Netherlands Institute for Innovative Ocular Surgery, Rotterdam, Netherlands.
authors.forename: Silke
authors.initials: S
authors.lastname: Oellerich
authors.affiliation: Netherlands Institute for Innovative Ocular Surgery, Rotterdam, Netherlands; Melles Cornea Clinic Rotterdam, Rotterdam, Netherlands; Amnitrans EyeBank Rotterdam, Rotterdam, Netherlands. Electronic address: research@niios.com.
authors.forename: Gerrit R J
authors.initials: GR
authors.lastname: Melles
mesh_terms: D064591:Allografts; D002452:Cell Count; D057111:Descemet Stripping Endothelial Keratoplasty; D004728:Endothelium, Corneal / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D005642:Fuchs' Endothelial Dystrophy / Q000473:pathology / Q000601:surgery*; D006084:Graft Rejection / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D013997:Time Factors