P-20   EXPRESSION OF CUTANEOUS LYMPHOCYTE ASSOCIATED ANTIGEN IN THE INFLAMATORY INFILTRATED OF EARLIER PATCHES OF ALOPECIA AREATA

L. Lacueva, G. Hausmann, Ch. Scheppers, R. Grimalt, J. Ferrando Dept. of Dermatology. Hospital Clinic. University of Barcelona. Spain.

The cutaneous lymphocyte associated antigen (CLA) is a glycoproteic adhesion molecule of the cellular surface whose epitopes (sialyl Lewis –a– and sialyl Lewis –x– carbohydrates) are recognized by the monoclonal antibody HECA-452.CLA is the ligand of the endotelial E-selectin and an appropriate marker of memory cutaneous T cells. CLA have been found in some cutaneous inflammatory disease as psoriasis, contact dermatitis, atopic dermatitis, vitiligo, cutaneous lymphoma, lichen planus and EICH. We have studied immunophenotypic characterization and specially the expression of the CLA in the inflammatory infiltrates of the initial patches of alopecia areata (AA) at intraepidermic, intrafollicular, perifollicular and perivascular level. Material and Methods: Twenty biopsies of the scalp corresponding to 12 patients affected of AA and 8 healthy controls were performed. The biopsies of the patients were performed in the margin of an initial patch, except for the patients with AA totalis and AA universalis that were performed in the occipital area. Immumunohistochemical studies were performed with monoclonal antibodies anti-CD1a, anti-CD4, anti- CD8, anti-CD68 and HECA-452 (anti-CLA), following the byotin-streptoavidin-peroxidasa method. Results: The highest cellularity were found in the biopsies of the patches of AA, specially in the perifollicular and the perivascular areas (34% and 36%, respectively). The predominant phenotype were T-helper lymphocytes (CD4) (41% of total cellularity). The CD4/CD8 ratio was 5.2. In the healthy controls the highest cellularity was at the intraepidermic site. The predominant phenotype was Langerhans cells (CD1a) (76%) and the CD4/CD8 ratio was of 1.47. The CLA expression was 29.34% in the biopsies of AA (HECA-452 positive cells), while in the biopsies of healthy controls was 5%. Comment: These data support the hypothesis that the CLA play a role in the ethiopathogenesis of AA. CLA should help the migration of the immunocompetent cells of the skin induced by the impact of the autoantigen in the hair follicle.