Uveitis Biomarker In Horses

Equine Recurrent Uveitis Biomarker: Kininogen is decreased in peripheral blood stream but increased in target tissue of autoimmune uveitis.

Zipplies JK, Hauck SM, Schöffmann S, Amann B, van der Meijden CH, Stangassinger M, Ueffing M, Deeg C. LMU Munich, Institute of Animal Physiology, Department of Veterinary Sciences, Munich, Germany.

Purpose. Equine recurrent uveitis is an incurable disease affecting the inner eye that leads to blindness, through activated T-cells that pass the blood-retinal barrier and destroy the retina. Serum markers are a desirable choice to monitor development of disease as sera are easy accessible and markers could serve to predict begin of disease or an imminent relapse. Methods. In this study, serum proteomes (depleted of high abundant serum proteins) of horses with ERU and healthy controls were compared with the 2D DIGE technique to identify differentially expressed proteins. The expression pattern of a candidate protein in retina and vitreous was validated by western blots and immunohistochemistry.

Results. Ten differentially expressed proteins could be identified by mass spectrometry (MALDI-TOF/TOF). Five proteins, namely IgM, IgG4 hc, Serotransferrin, alpha-2HS-Glycoprotein and Complementfactor B were upregulated in uveitic state, whereas the five proteins Albumin, Apolipoprotein A-IV and H, IgG5 hc and high molecular weight Kininogen showed a significantly lower expression in sera of uveitis cases. Interestingly, Kininogen was significantly upregulated in target tissues vitreous and retina. HK is a plasma protein with multiple physiological functions, with an important role in inflammation and promoting neovascularization. Most interesting is the as of yet unadressed association of HK with uveitis. With immunohistochemistry, we could show co-expression of Kininogen and VEGF in inflamed eyes.

Conclusions. Since neovascularization plays a major role in the pathogenesis of uveitis, the identification of a proangiogenic factor in the retina presents an important finding and may contribute to elucidate the pathogenesis of uveitis.

PMID: 19696180 [PubMed - as supplied by publisher]

See Also: Equine Recurrent Uveitis Biomarker Research a Real Eye Opener
Genetic risk factors for insidious equine recurrent uveitis in Appaloosa horses