Interleukin-17 in various ocular surface inflammatory diseases.

Area of Science:

• Ophthalmology
• Immunology

Background:

• T helper 17 (Th-17) cells and their cytokine, interleukin-17 (IL-17), are increasingly recognized in ocular inflammatory conditions.
• Previous research suggests a link between Th-17 cells/IL-17 and diseases like uveitis, scleritis, and dry eye syndrome.

Purpose of the Study:

• To investigate the presence and concentration of IL-17 in tear fluid across a spectrum of ocular surface inflammatory diseases.
• To determine the clinical correlation between tear IL-17 concentrations and the severity of ocular surface inflammation.

Main Methods:

• Tear samples were collected from normal subjects (n=28) and patients (n=141) diagnosed with meibomian gland dysfunction (MGD), dry eye syndrome (DES), Sjögren syndrome (SS), Stevens-Johnson syndrome (SJS), graft-versus-host disease (GVHD), filamentary keratitis, and autoimmune keratitis.
• Interleukin-17 (IL-17) concentrations in tears were measured.
• Clinical severity was assessed using epitheliopathy scores based on corneal and conjunctival fluorescein staining.

Main Results:

• Mean tear IL-17 concentrations were significantly higher in patients with filamentary keratitis, GVHD, autoimmune keratitis, SS, DES, MGD, and SJS compared to normal subjects.
• Tear IL-17 concentration showed a significant positive correlation with clinical epitheliopathy scores in patients with systemic inflammatory diseases.
• No significant correlation was found between tear IL-17 levels and clinical severity in dry eye patients without systemic inflammation.

Conclusions:

• Elevated tear IL-17 is a characteristic finding in various ocular surface inflammatory diseases.
• Tear IL-17 concentration serves as a potential biomarker for corneal disease severity, especially in the context of systemic inflammatory conditions affecting the eye.