Innate Immunity Biomarkers for Early Detection of Keratoconus.

Purpose: To compare toll-like receptors 2 (TLR2) and 4 (TLR4) expression in cells of corneal and conjunctival epithelium between unilateral KC patients and control subjects.

Methods

Prospective cross-sectional case-control study, including 50 unilateral KC patients and 20 control subjects. TLR2 and TLR4 expression was measured with flow cytometry.

Results

Mean expression of TLR2 and TLR4, in corneal and conjunctival cells, was significantly higher in KC than in subclinical and control groups (all p < 0.0001). TLR2 expression in corneal epithelial cells can predict with the highest sensitivity and specificity the probability of KC existence compared to a control (area under the curve 0.995, 95% CI: 0.987-1.000; p < 0.0001). Corneal TLR2 expression also has a predictive capacity to discriminate between subclinical KC and controls (area under the curve 0.989, 95% CI: 0.975-1.000; p < 0.0001).

Conclusions

TLR2 and TLR4 expression in corneal and conjunctival epithelial cells may constitute predictive biomarkers for the early detection of KC.