title: Immunopathogenesis of vernal keratoconjunctivitis.
abstract: We have analyzed the in situ distribution of immune cells in the conjunctival biopsy specimens obtained from patients with active vernal keratoconjunctivitis (VKC). We used immunohistochemical techniques and a panel of monoclonal and polyclonal antibodies. Our data point to a complex immunopathogenesis of the disease. Distinct components involved in IgE-mediated immune mechanisms, as well as humoral and cell mediated immune mechanisms were detected in the conjunctival tissues. In addition, we investigated the presence and distribution of adhesion molecules. In the normal conjunctiva, intercellular adhesion molecule-1 (ICAM-1) was expressed only on the vascular endothelium, lymphocyte function associated antigen-1 (LFA-1) and intercellular adhesion molecule-3 (ICAM-3) on epithelial and stromal mononuclear cells, and very late activation antigen-4 (VLA-4) on a few stromal mononuclear cells. Endothelial leukocyte adhesion molecule-1 (ELAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expression was not detected. In VKC a marked increase of all these antigens was observed. Strong ICAM-1 expression was induced on the basal epithelial cells, and vascular endothelium. Furthermore, about 30% of the stromal mononuclear cells expressed ICAM-1. LFA-1 and ICAM-3 were expressed on the majority of infiltrating mononuclear cells. VLA-4 expression was noted on about 25% of the stromal mononuclear cells. ELAM-1 and VCAM-1 were induced on the vascular endothelial cells. Our results suggests that increased expression of adhesion molecules in VKC promotes the recruitment of inflammatory cells through blood vessels and the cell interaction between lymphocytes and antigen presenting cells, among lymphocytes, as well as between lymphocytes and epithelial cells.
authors.affiliation: Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
authors.forename: A M
authors.initials: AM
authors.lastname: Abu el-Asrar
authors.forename: K
authors.initials: K
authors.lastname: Geboes
authors.forename: K F
authors.initials: KF
authors.lastname: Tabbara
authors.forename: J J
authors.initials: JJ
authors.lastname: van den Oord
authors.forename: L
authors.initials: L
authors.lastname: Missotten
mesh_terms: D015703:Antigens, CD; D000943:Antigens, Differentiation; D015815:Cell Adhesion Molecules / Q000302:isolation & purification; D003228:Conjunctiva / Q000276:immunology*; D003233:Conjunctivitis, Allergic / Q000276:immunology*; D019040:E-Selectin / Q000032:analysis; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D007150:Immunohistochemistry; D039041:Integrin alpha4beta1; D019012:Integrin beta1 / Q000302:isolation & purification; D016023:Integrins / Q000302:isolation & purification; D018799:Intercellular Adhesion Molecule-1 / Q000302:isolation & purification; D016201:Receptors, Lymphocyte Homing / Q000302:isolation & purification; D016029:Receptors, Very Late Antigen / Q000302:isolation & purification; D019010:Vascular Cell Adhesion Molecule-1 / Q000302:isolation & purification
chemical_list: D015703:Antigens, CD; D000943:Antigens, Differentiation; D015815:Cell Adhesion Molecules; D019040:E-Selectin; C483616:ICAM3 protein, human; D039041:Integrin alpha4beta1; D019012:Integrin beta1; D016023:Integrins; D016201:Receptors, Lymphocyte Homing; D016029:Receptors, Very Late Antigen; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1; D007073:Immunoglobulin E