Conjunctivitis Research Today is a free monthly online journal that collates and summarizes the latest research about Conjunctivitis, including details on pink eye, symptoms, causes, treatment, medication.

Allergic tears promote upregulation of eosinophil adhesion to conjunctival epithelial cells in an ex vivo model: inhibition with olopatadine treatment.

Cook EB, Stahl JL, Brooks AM, Graziano FM, Barney NP

Departmentsof Medicine, School of Medicine, University of Wisconsin-Madison, 53792, USA. ebc@medicine.wisc.edu

PURPOSE: The mechanism by which eosinophils adhere to the ocular surface during allergic inflammation is unknown. This study examined whether the incubation of human conjunctival epithelial cells (HCEs) with tears from allergic subjects promotes eosinophil adhesion, and it examined the effect of treatment with olopatadine on this process. METHODS: Allergic subjects (n = 6) and nonallergic subjects (n = 4) were treated in season for 1 week with olopatadine in one eye while the other eye remained untreated. Tears were collected from both eyes with the use of a microcapillary tube. HCEs were acquired by enzymatic digestion of cadaveric conjunctival tissues. Confluent cultures of HCEs were treated with diluted tears for 24 hours before incubation with peripheral blood eosinophils (purified with negative magnetic bead selection). Eosinophil adhesion was measured with an eosinophil peroxidase assay. RESULTS: Incubation of HCEs with tears from allergic subjects significantly upregulated eosinophil adhesion compared with eosinophil adhesion to untreated HCEs or with HCEs treated with nonallergic tears and untreated HCEs (P < 0.05). Eosinophil adhesion to HCEs treated with tears from olopatadine-treated allergic subjects was inhibited (P < 0.01) compared with tear-stimulated adhesion observed from untreated eyes. Percentage of inhibition was 43.3% +/- 13.9% (mean +/- SD). Blocking antibodies demonstrated that eosinophil adhesion to HCEs in vitro involved beta2 integrins on eosinophils but not intercellular adhesion molecule-1 on human HCEs. CONCLUSIONS: Tears collected from allergic subjects contain bioactivity capable of upregulating eosinophil adhesion to HCEs in vitro. Inhibition of this process by treatment of subjects with olopatadine suggests that some of the cellular targets of this drug may play a role in promoting eosinophil adhesion.

Published 31 July 2006 in Invest Ophthalmol Vis Sci, 47(8): 3423-9.
Full-text of this article is available online (may require subscription).

© 2004-2008 Conjunctivitis Research Today. All Rights Reserved.