Abstract
Purpose :
The etiology of Dry Eye Disease (DED) is multifactorial impacting tear quality and associated with ocular surface inflammation. Elevated inflammatory cytokines and chemokines in tears have been correlated to clinical endpoints and/or disease severity. While only a small volume is available for sampling, tears have the advantage of being proximal to the ocular surface and are ideal to evaluate biomarkers using non-invasive techniques. The purpose of this research was to compare levels of 45 inflammatory protein markers in tear samples collected from healthy and DED patient eyes. A novel bioanalytical platform for tear biomarker analysis was applied to determine distinct baseline biomarker profile in these 2 populations.
Methods :
Tear samples were collected from DED patients and healthy subjects in 2 separate studies utilizing similar tear collection techniques. Approximately 3-5 microlitre of tears were collected into capillary tubes and analyzed using a targeted 48-plex Olink cytokine panel. The unique Proximity Extension Assay (PEA) approach with qPCR readout and dual recognition by DNA-coupled antibodies enabled multiplexed immunoassays of proteins using low tear volume. The Mann-Whitney U test was performed to compare the distributions of biomarkers from healthy subjects vs DED patients. Correlation analysis and variance component analysis were used to evaluate the impact of multiple factors on biomarker values, including sample dilution, collection eye, and multiple collections.
Results :
The novel Olink platform was effectively used to determine 45 inflammatory protein markers in tear samples. Biomarker analysis of healthy vs. DED tear samples demonstrated that levels of key inflammatory markers (IL-1B, IL-6, IL-10, IL-17c, IFNγ, and TNFα) were higher in DED vs. healthy subject eyes. In addition, there was an impact of sample dilution (2-fold vs. 4-fold vs. 8-fold) on data for certain markers indicating that collection and analysis method optimization is needed for future use.
Conclusions :
To our knowledge this is the first time that Olink platform technology was successfully used for such a comprehensive evaluation of biomarker profile in tears from healthy subjects and DED patients, demonstrating the utility of this platform for future tear biomarker analysis.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.