Abstract
Abstract: :
Purpose: To conduct a coordinated evaluation of ocular surface marker expression in response to allergen provocation in comparison to seasonal allergen exposure. Ocular surface cells were examined for expression of CD23 and ICAM-1. These receptors are markers of ocular allergic inflammation which are involved with regulation of IgE and cell adhesion, respectively. Methods: Eight subjects with allergies to grass pollen (confirmed by skin prick test) were examined in four separate visits (Visit 1: out-of-season, no allergen challenge; Visit 2: out-of-season, allergen challenge; Visit 3: in season, no topical or systemic anti-histamine; Visit 4: in season, topical use of olopatadine drops as needed for 2 weeks). Ocular surface cells were collected using impression cytology. The ocular surface cells were examined for expression of CD23 and ICAM-1 using two-color antibody staining and flow cytometry analysis. Results: Expression of both CD23 and ICAM-1 was significantly greater in season than out of season (p = 0.005 and 0.036 respectively). CD23 was also upregulated 30 min post ocular allergen challenge (p = 0.038), while ICAM-1 expression was unaffected at this time point. Conclusion: In season topical use of olopatadine for two weeks resulted in a significant decrease in expression of CD23 (p = 0.030). The rapid upregulation of CD23 expression in response to allergen challenge implies a direct effect of mast cell activation, which could explain why the mast cell stabilizer/antihistamine, olopatadine, has a profound effect on seasonal CD23 expression.
Keywords: 437 inflammation • 365 conjunctiva • 413 flow cytometry