Secondary Data Analysis of Inflammation-Related mRNAs in Conjunctival Impression Cytology Samples of Aniridia Patients

Abstract

Purpose: Aniridia is a rare corneal disease that is often associated with aniridia-associated keratopathy (AAK). In AAK, the conjunctival tissue crosses the limbal border, forming a corneal pannus that extends into the corneal center. With increasing AAK severity, corneal pannus formation, vascularization, and ocular surface inflammation increase. The purpose of this study was to investigate inflammation-related mRNA expression in conjunctival epithelial cells in AAK and its relationship with AAK severity. Methods: Using impression cytology, bulbar conjunctival cells were sampled from 20 subjects with congenital aniridia and 20 age-matched and sex-matched healthy control subjects. RNA was extracted, and mRNA analyses were performed using microarray, which was evaluated for inflammatory markers. Results: In the analyzed aniridia subjects, 70 deregulated mRNAs encoding proinflammatory or antiinflammatory cytokines or factors associated with chronic inflammation, including increased IL-1, IL-8, and MIP3A/CCL20 mRNA. The most downregulated mRNA was TIMP3, and the most upregulated mRNA was Protein c-Fos. Of the 70 mRNAs, 14 inflammation-related genes were altered only in the mild AAK forms, whereas only 2 mRNAs were altered only in the severe AAK forms (TLR4 and PPARG). Conclusions: The expression of numerous proinflammatory and antiinflammatory cytokines is deregulated at the ocular surface of aniridia subjects with mild AAK. Thus, early antiinflammatory treatment may prevent or slow down corneal scarring and pannus formation in aniridia subjects.