title: Interferon gamma-inducible protein-10 (IP-10) and eotaxin as biomarkers in age-related macular degeneration.
abstract: OBJECTIVE
  To analyze serum cytokine levels in subjects with different stages of AMD and to study the expression of salient cytokines in postmortem eyes with AMD.
  
  
  METHODS
  A suspension array system was used to analyze sera (n = 18 to 20/group) from control subjects and those with early AMD (AREDS stage 1), intermediate dry AMD (AREDS stage 3), advanced AMD with geographic atrophy (GA), or neovascular AMD (CNV). Postmortem eyes with AMD or control eyes were examined immunohistochemically for expression of IP-10 and eotaxin (n = 4 to 8/group).
  
  
  RESULTS
  Serum eotaxin and IP-10 levels were significantly elevated in all stages of AMD, except for eotaxin levels in neovascular AMD (P < 0.07). The peak of serum IP-10 concentration was at intermediate dry AMD. In donor eyes, IP-10 and eotaxin expressions were increased in the RPE of eyes with early AMD, GA, and CNV. Eotaxin accumulated within the layer of basal linear/laminar deposits in all stages of AMD, while IP-10 was mainly in eyes with GA and CNV. IP-10 was abundant in the connective tissue matrix associated with CNV, and eotaxin was usually present but more focally and with less intense staining. Both IP-10 and eotaxin were expressed by neovascular endothelial cells. Both IP-10 and eotaxin were expressed in the neurosensory retina, but there was no detectable difference in staining between eyes with or without AMD.
  
  
  CONCLUSIONS
  IP-10 and eotaxin may be early biomarkers in AMD. The authors hypothesize that the relative balance between levels of IP-10 and eotaxin is critical in regulating the neovascular response.
authors.affiliation: Schepens Eye Research Institute, Boston, Massachusetts 02114, USA.
authors.forename: Fong Ming
authors.initials: FM
authors.lastname: Mo
authors.forename: Alan D
authors.initials: AD
authors.lastname: Proia
authors.forename: Walter H
authors.initials: WH
authors.lastname: Johnson
authors.forename: Desiree
authors.initials: D
authors.lastname: Cyr
authors.forename: Kameran
authors.initials: K
authors.lastname: Lashkari
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood* / Q000378:metabolism; D054413:Chemokine CCL11 / Q000097:blood* / Q000378:metabolism; D054357:Chemokine CXCL10 / Q000097:blood* / Q000378:metabolism; D020256:Choroidal Neovascularization / Q000378:metabolism; D005260:Female; D057092:Geographic Atrophy / Q000378:metabolism; D006801:Humans; D007124:Immunoenzyme Techniques; D008268:Macular Degeneration / Q000097:blood* / Q000378:metabolism; D008297:Male; D055213:Retinal Pigment Epithelium / Q000378:metabolism*
chemical_list: D015415:Biomarkers; C515456:CCL11 protein, human; C114753:CXCL10 protein, human; D054413:Chemokine CCL11; D054357:Chemokine CXCL10