Human Tear Protein Analysis Using a Quantitative Microfluidic System: A Pilot Study.

Area of Science:

• Ophthalmology
• Biomarker Discovery
• Proteomics

Background:

• Human tears contain potential biomarkers for diagnosing and managing dry eye disease (DED).
• Current diagnostic methods for DED may not fully capture the complexity of the disease.
• Quantitative analysis of tear proteins offers a promising avenue for objective DED assessment.

Purpose of the Study:

• To investigate the hypothesis that tear protein profiles can be detected and are repeatable using a miniaturized quantitative microfluidic system.
• To assess the reliability of a microfluidic system for analyzing tear protein panels in a clinical setting.

Main Methods:

• A prospective, controlled pilot study involving ten participants.
• Tear samples (>4 µL) collected using glass microcapillary tubes.
• Analysis of tear proteins (14-230 kDa) using a miniaturized quantitative microfluidic system (Protein 230 LabChip with Agilent 2100 Bioanalyzer).

Main Results:

• Several key proteins (lysozyme C, lipocalin 1, IgA light chain, zinc-α2-glycoprotein, albumin, lactoferrin) were consistently identified.
• No significant differences in individual protein concentrations were observed between two separate visits.
• High correlation (0.63-0.98) between visits confirmed the repeatability of protein measurements.

Conclusions:

• The quantitative microfluidic system provides repeatable measurements of tear protein profiles.
• This validated method is quick, affordable, requires minimal tear volume, and is suitable for clinical integration.
• Further research in larger cohorts is recommended to explore its utility across diverse patient groups.