Abstract
Purpose: :
To identify possible uveitis serum markers in a spontaneous model of uveitis (ERU) in horses. After thorough validation, such markers can add to and improve existing paraclinical tools, most importantly surrogate markers such as auto-antibody tests in patient sera.
Methods: :
In order to identify potential biomarker candidates, we first systematically compared the proteomes of individual ERU cases with healthy controls by proteomic profiling using 2-D difference-gel-electrophoresis (2-D DIGE) followed by tandem mass spectrometry. For biomarker validation, we used 116 additional ERU cases and 115 controls.
Results: :
A total of seven differentially expressed proteins were identified. Besides the upregulation of IgG and the significant lower expression of albumin, Antithrombin III, Vitamin D binding protein, we found complement components C1q and C4, to be downregulated in uveitic state. Interestingly, Pigment epithelium-derived factor (PEDF), a marker already detected by 2DE differential proteome analysis in ERU target tissues vitreous and retina found to be also significantly downregulated in sera. The lower expression of PEDF in sera of horses with uveitis could be verified in a cohort of 116 ERU cases and 115 healthy controls.
Conclusions: :
Our findings of a significant lower PEDF expression in ERU cases also in the periphery of the eye proves PEDF as a promising uveitis biomarker.
Keywords: uveitis-clinical/animal model • autoimmune disease • protein structure/function