Flow cytometric analysis of HLA-DR antigen in conjunctival epithelial cells of patients with cystic fibrosis

Purpose Cystic fibrosis (CF) is an autosomal-recessive genetic disorder. The disease affects all secretory epithelia including the eye and belongs to the group of ocular surface epithelial diseases, termed keratoconjunctivitis sicca that develop in dry eye. In the pathogenesis of dry eye, inflammation plays a crucial role. The aim of this study was to investigate the expression of HLA-DR on conjunctival epithelial cells from patients with CF. Materials and methods Twenty-five patients with CF and 25 normal subjects underwent ocular examination. Tear film break-up time (TBUT), Schirmer test, lissamine green staining, and conjunctival impression cytology were carried out. Cells were processed for flow cytometry, by using monoclonal antibodies to HLA-DR. Results The Schirmer test and TBUT scores were significantly lower in CF patients compared with controls. A significant increase of HLA-DR expression on epithelial cells was found in patients with CF compared with normal eyes. The Schirmer and TBUT test were positively correlated with HLA-DR expression for the percentage of cells. Conclusion These results suggest that conjunctival epithelial cells play an important proinflammatory role in ocular changes in CF patients. Our findings confirm the presence of an inflammatory background and the immune nature of this disease. HLA-DR measurement might be a useful method for monitoring of inflammatory processes in the conjunctiva and could be helpful in the use of anti-inflammatory drugs in the treatment of ocular findings in CF patients.