[Limbal stem cell deficiency after chemical burns : investigations on the epithelial phenotype and inflammation status].

Limbal stem cell deficiency (LSCD) is clinically characterized by growth of fibrovascular pannus onto the corneal surface, chronic inflammation and impaired visual acuity. The aim of this study was to characterize the pannus tissue. Total RNA was isolated from six pannus samples and protein from three pannus samples from patients with LSCD caused by chemical burns. Normal human corneal tissue (n=6) and conjunctiva (n=6) were used as control tissues. The expression of the epithelial lineage markers keratin 3 (K3), K19 and MUC5AC, the inflammatory markers IL-1beta, ICAM-1 and VEGF was analyzed by Western Blotting and/or real-time PCR. Normal corneal tissue had a higher expression of K3 and a lower expression of K19 and MUC5AC in comparison to normal conjunctiva. A higher expression of inflammatory markers was seen in conjunctiva compared to corneal tissue. The pannus tissue showed a similar expression of lineage markers to conjunctiva but a higher expression of most inflammatory markers as compared to both control tissues. The analyzed samples of pannus in LSCD resembled conjunctiva and not cornea and showed a high expression of inflammatory markers indicating chronic inflammation.