Distribution of lymphocytes and cell adhesion molecules in iris biopsy specimens from patients with uveitis
D. Wakefield, P. McCluskey and P. Palladinetti
Laboratory of Ocular Immunology, School of Pathology, University of New South Wales, Kensington, Australia.
To investigate the mechanisms responsible for lymphocyte accumulation in
the eye in uveitis, we examined iris biopsy specimens that were obtained
from 10 patients with uveitis and from 12 patients with cataract for the
presence of adhesion molecules on vascular endothelium, uveal cells, and
infiltrating inflammatory cells. Immunoperoxidase staining of iris biopsy
specimens that were obtained from patients with uveitis revealed an
increased expression of intercellular adhesion molecule 1 (CD54) on
endothelial cells, lymphocytes, fibroblasts, and iris epithelial cells.
Seven of the 10 iris biopsy specimens that were obtained from patients with
uveitis had a significant inflammatory cell infiltrate. Lymphocytes (CD2
positive) that infiltrated the iris were predominantly helper T cells (70%)
and strongly expressed the lymphocyte function-associated antigen 1 (CD11a,
CD18) molecule, the ligand for intercellular adhesion molecule 1, in four
of the seven biopsy specimens. In contrast, small numbers of lymphocytes
were evident in only three (25%) of the iris biopsy specimens that were
obtained from patients with cataract. Vascular endothelium from the latter
group did not express intercellular adhesion molecule 1 or endothelial
leukocyte adhesion molecule 1. The results of this study revealed the
enhanced expression of vascular endothelial cell and lymphocyte adhesion
molecules in the iris biopsy specimens that were obtained from patients
with uveitis. The presence of these receptors and their presumed ligands
may have important implications for the role of these molecules in the
pathogenesis of uveitis.
