Abstract
Purpose :
Lens-induced uveitis (LIU) is an intraocular inflammatory condition that occurs following aggravation of the lens capsule and release of lens proteins into the eye. The diagnosis of LIU can be challenging and distinguishing it from other causes of intraocular inflammation, including postoperative endophthalmitis, can be difficult. The purpose of this study is to profile vitreous protein expression of LIU and infectious endophthalmitis patients.
Methods :
Liquid vitreous biopsies were collected from 3 groups: control subjects (n = 4) undergoing pars plana vitrectomy to repair an idiopathic macular hole (IMH), test subjects with lens-induced uveitis (n=9), and test subjects (n = 6) with infectious endophthalmitis. Vitreous samples were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and proteins were identified and quantified using a data-independent approach (DIA). Protein expression changes (i.e., relative intensities) were evaluated by analysis of variance (1-way ANOVA; significant p-value <0.05), gene ontology, and pathway analysis, to identify candidate biomarkers and pathways for prospective studies.
Results :
We identified a mean of 399 proteins in control (IMH), 385 in LIU, and 419 in endophthalmitis vitreous. In LIU vitreous, 45 proteins were significantly differentially expressed proteins (20 upregulated and 25 downregulated) compared to controls, including lens-specific proteins (i.e. crystallins). Endophthalmitis vitreous exhibited 149 significantly differentially expressed proteins (87 upregulated and 62 downregulated) compared to controls and was characterized by the presence of elevated neutrophil specific markers. A total of 134 proteins were differentially expressed between LIU and endophthalmitis samples (55 upregulated and 79 downregulated) and lens-specific proteins were the greatest unregulated proteins in LIU samples.
Conclusions :
The LIU vitreous proteome is characterized by the upregulation of crystallins while endophthalmitis samples are distinguished by the presence of proteins related to neutrophil degranulation and microbial antigen presentation. This is the first proteomic study to identify possible biomarkers in the vitreous for diagnosing LIU and differentiating it from infectious endophthalmitis.
This is a 2021 ARVO Annual Meeting abstract.