Título

INCREASED INFLAMMATORY MEDIATORS IN THE TEAR FILM AND OCULAR SURFACE TISSUE IN KERATOCONUS PATIENTS

Objetivo

This study aimed to characterize inflammatory mediators in the tear film of keratoconus patients (KC), investigate their gene expression on corneal epithelial cells and their immune demarcation on conjunctival epithelial cells compared with healthy individuals.

Método

This transversal study involved 30 KC patients and 16 healthy individuals. Tear collection was obtained by ocular surface washing with 60 μl of sterile buffered saline solution (BSS). The levels of IL-5, IL-13, IL-2, IL-6, IL-10, IFN-γ, TNF-α, and IL-4 were detected with the LEGENDplex HU Th1/Th2 panel kit and analyzed by flow cytometer. Corneal epithelia were obtained by manual keratectomy from KC patients candidates to CXL and from healthy individuals candidates to PRK (control group). Samples were immediately stored at −70°C until further mRNA extraction and RT-PCR analysis to measure IL-5 and IL-6 gene expression. Conjunctival epithelium samples were obtained using impression cytology (IC) and were analyzed by immunohistochemistry/confocal microscopy looking for immunoreaction with IL-5 and IL-6.

Resultado

Lacrimal cytokines concentration was higher in the KC patients than controls in 6 of 7 cytokines analyzed. Gene expression of IL-5 and IL-6 in the corneal epithelium was higher in patients with keratoconus when compared to the control group (IL-5 was 50% higher and IL-6 was 20% higher, respectively). Immunohistochemical analyzes showed greater immunostaining of IL-5 and IL-6 in the conjunctival epithelium of KCN patients while compared to the control group.

Conclusão

This study suggests that inflammatory activity seems to be involved in the pathogenesis of keratoconus. Cytokines with higher concentration in the tear film had higher gene expression in the corneal epithelium and were detected with greater intensity in the conjunctival epithelium of patients with keratoconus.