Preliminary evidence for 'aberrant' expression of the leukocyte integrin LFA-1 (CD11a/CD18) on conjunctival epithelial cells of patients with mite allergy

Background: We have previously shown aberrant expression of the 'leukocyte' integrin LFA-1 on epithelial cells in chronic autoimmune thyroiditis. In t he present study we investigated whether conjunctival epithelial cells, whi ch bear the adhesion molecule ICAM-1 on their surface during allergic infla mmation, may also aberrantly express its natural ligand, the 'leukocyte' in tegrin LFA-1. Methods: We studied 13 patients with rhinoconjunctivitis alle rgic to mites, chronically exposed to the allergen, 11 patients allergic to pollen tested out of the pollen season and 8 normal volunteers. Single and double immunocytochemical staining of conjunctival smears was employed. Re sults: LFA-1 staining on epithelial cells was demonstrated in 12/13 patient s allergic to mites and not in normal controls or in patients allergic to p ollen tested out of the pollen season. The epithelial localization of LFA-1 was confirmed by double staining with anti-LFA-1 and anti-cytokeratin anti bodies (both immunocytochemical and immunofluorescence). Conclusions: Coexp ression of LFA-1 and ICAM-1 during persistent allergen stimulation may be r elevant for interaction between epithelial cells and activated effector cel ls, such as eosinophils, which bear on their surface both ICAM-1 and its be ta2 integrin ligands. Copyright (C) 2001 S. Karger AG, Basel.