title: Cytokine and chemokine profiles of aqueous humor and serum in horses with uveitis measured using multiplex bead immunoassay analysis.
abstract: OBJECTIVE
  To determine whether horses with clinically diagnosed Equine Recurrent Uveitis (ERU) and those with Leptospirosis infection have a specific cytokine profile in their aqueous humor (AH) and serum that differs from horses with uveitis secondary to other ocular inflammatory processes and from horses with normal eyes.
  
  
  METHODS
  Twenty-five client-owned horses with uveitis that were presented to the North Carolina State University Ophthalmology Service, and four University-owned horses without history or clinical signs of ocular disease.
  
  
  METHODS
  Samples of AH and serum were obtained from horses with ERU (n=13), acute or non-recurrent uveitis (UV; n=7), uveitis secondary to infectious keratitis (IK; n=5), and normal eyes (N; n=4). Cytokine levels in AH and serum were quantified using a multiplex bead immunoassay. Leptospiral antibody titers in serum and AH and PCR for Leptospiral DNA in AH were performed.
  
  
  RESULTS
  In the AH of horses with ERU, increased levels of IL-1a, IL-4, IL-6, IL-8, IL-12p70, FGF-2, G-CSF, and RANTES were measured compared to UV, IK and N eyes, but the differences were not significant. However, IL-10 was significantly higher in ERU eyes compared to IK and N (P=0.029; 0.013), and IP-10 in ERU eyes was significantly higher than in UV and N (P=0.004). Furthermore, MCP-1 was significantly higher in ERU than N (P=0.04). In the serum, increased levels of IL-1a, IL-4, IL-6, IL-8, IL-12p70, fractalkine, and G-CSF were measured in horses with ERU, but the levels were not significantly higher than those observed in UV, IK, or N horses. However, serum IP-10 levels in horses with ERU were significantly higher than in UV and N horses (P=0.005) and MCP-1 levels were significantly higher in ERU than N (P=0.03). Horses with marked ocular inflammation had significantly higher serum levels of G-CSF, IL-1a, fractalkine, IL-13, IL-4, IL-17a, IL-12p70, IFN-γ, and MCP-1. Elevated IL-10 in AH was significantly associated with disease chronicity, both overall and in ERU eyes (P=0.049), and in horses with positive ocular leptospiral titers or leptospiral PCR, significant elevations of IL-10 (P=0.0018; 0.0032) and IP-10 (P=0.0342; 0.043) were detected in the AH compared to leptospiral negative eyes.
  
  
  CONCLUSIONS
  The anti-inflammatory cytokine IL-10 and the pro-inflammatory cytokine IP-10 appear to play an important role in ERU. Further studies are needed to further clarify and characterize cytokine profiles of specific ocular inflammatory diseases, but multiplex bead immunoassay technology shows promise as a diagnostically valuable tool.
authors.affiliation: Department of Clinical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, NC 27607, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Curto
authors.affiliation: Department of Molecular Biomedical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, NC 27607, USA.
authors.forename: Kristen M
authors.initials: KM
authors.lastname: Messenger
authors.affiliation: Department of Clinical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, NC 27607, USA.
authors.forename: Jacklyn H
authors.initials: JH
authors.lastname: Salmon
authors.affiliation: Department of Clinical Sciences, North Carolina State University College of Veterinary Medicine, Raleigh, NC 27607, USA. Electronic address: bgilger@ncsu.edu.
authors.forename: Brian C
authors.initials: BC
authors.lastname: Gilger
mesh_terms: D000818:Animals; D001082:Aqueous Humor / Q000276:immunology; D015415:Biomarkers / Q000097:blood / Q000378:metabolism; D018925:Chemokines / Q000097:blood / Q000378:metabolism*; D016207:Cytokines / Q000097:blood / Q000378:metabolism*; D006734:Horse Diseases / Q000097:blood / Q000175:diagnosis / Q000276:immunology*; D006736:Horses; D007118:Immunoassay; D018836:Inflammation Mediators / Q000097:blood / Q000378:metabolism; D007922:Leptospirosis / Q000097:blood / Q000276:immunology / Q000662:veterinary; D014605:Uveitis / Q000097:blood / Q000276:immunology* / Q000662:veterinary*
chemical_list: D015415:Biomarkers; D018925:Chemokines; D016207:Cytokines; D018836:Inflammation Mediators
keywords: Chemokine; Cytokine; Horse; Leptospirosis; Multiplex; Uveitis