Proteomics Differentiate Between Thyroid-Associated Orbitopathy and Dry Eye Syndrome.

Area of Science:

• Ophthalmology
• Proteomics
• Biochemistry

Background:

• Thyroid-associated orbitopathy (TAO) frequently co-occurs with dry eye syndrome.
• Symptom overlap between TAO and dry eye complicates accurate differential diagnosis.
• Specific protein markers are needed for differentiating these conditions.

Purpose of the Study:

• To identify specific protein markers in tear fluid for differentiating TAO from dry eye.
• To investigate the proteomic differences in tear fluid among patients with TAO, dry eye, and healthy controls.

Main Methods:

• Tear fluid samples were collected from 120 subjects across four groups: TAO, TAO with dry eye, dry eye, and healthy controls.
• Proteomic analysis was performed using matrix-assisted laser desorption ionization mass spectrometry.
• Identified proteins were further validated using antibody microarrays.

Main Results:

• Proteomics revealed deregulated proteins in TAO and dry eye.
• Compared to dry eye, several proteins including proline-rich protein 1 (PROL1) and calgranulin A (S10A8) were downregulated in TAO.
• Antibody microarrays confirmed significant changes in PROL1, uridine diphosphate (UDP)-glucose-dehydrogenase (UGDH), and proline-rich protein 4 (PRP4) between TAO and other groups. Protein dysregulation was linked to inflammation and cell death.

Conclusions:

• Tear fluid proteomics identified distinct protein profiles in TAO, with upregulated inflammatory and downregulated protective proteins.
• These protein panels may serve as valuable indicators for disease activity and ocular surface disease in TAO patients.
• The identified proteins, particularly PROL1, UGDH, and PRP4, show potential as diagnostic markers for TAO.