Vergouwen DP, Kolijn PM, de Hoog J, de Boer JH, Los LI, Gijs M, Erckens RJ, de Jong PH, Rothova A, Ten Berge JC, Schreurs MW. Potential Biomarkers for Noninfectious Scleritis Identified by Serum and Tear Fluid Proteomics.
OPHTHALMOLOGY SCIENCE 2024;
4:100407. [PMID:
38054106 PMCID:
PMC10694766 DOI:
10.1016/j.xops.2023.100407]
[Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 09/20/2023] [Accepted: 09/28/2023] [Indexed: 12/07/2023]
Abstract
Purpose
Scleritis is an extremely painful and potentially blinding inflammation of the sclera with unknown pathogenesis and unpredictable course. To gain insight in its disease process and identify biomarker candidates, we performed extensive proteomics in serum and tear fluid.
Design
Prospective multicenter cohort study.
Participants
A total of 121 patients with noninfectious scleritis (of which 39 active cases), 30 healthy controls, and 23 disease controls (uveitis and rheumatoid arthritis) were enrolled in the Netherlands from 2020 to 2022.
Methods
Serum, tear fluid of both eyes, and clinical data were gathered. The level of 368 inflammatory proteins was measured using proximity extension assays. Results were validated in an independent cohort of 15 patients with scleritis, and using addressable laser bead immunoassay, or enzyme-linked immunoassays. In addition, we studied an extended panel of matrix metalloproteinases in tear fluid of necrotizing scleritis with addressable laser bead immunoassay.
Main Outcome Measures
Statistically significant differences in the level of inflammatory proteins between patients with scleritis and control groups.
Results
Proteomics revealed 18 significantly upregulated or downregulated serum proteins in active scleritis cases compared with all control groups in both the discovery cohort and the validation cohort. The most upregulated protein was nuclear migration protein nudC (NudC; P = 0.0032), a protein involved in neurogenesis. The other significant hits included proteins involved in T-cell activation, apoptosis, epithelial barrier maintenance, and angiogenesis. Our tear fluid analysis showed matrix metalloproteinase 9 (MMP9) to be upregulated in the tear fluid of patients with scleral necrosis.
Conclusions
The results of our proteomics analysis suggest a role for neurogenesis, T-cell activation, disruption of epithelial barrier, and angiogenesis in the pathogenesis of scleritis, and highlight MMP9 and NudC as biomarkers with potential clinical relevance.
Funding Disclosures
The authors have no proprietary or commercial interest in any materials discussed in this article.
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