PHARMACOLOGICAL MODULATION BY CETIRIZINE OF SOME ADHESION MOLECULES EXPRESSION IN PSORIATIC SKIN-LESIONS

Background. Adhesion molecules play a major role in the pathogenesis o f inflammatory skin diseases by regulating lymphocyte trafficking and homing in an inflamed area. Methods. The expression of the lymphocyte function-associated antigen-1 (LFA-1) and of its ligand, the intercell ular adhesion molecule-1 (ICAM-1) has been studied in psoriatic skin l esions of 10 patients with guttate, nummular, and palmoplantar psorias is. In addition, the peculiar immunophenotype of infiltrating cells (C D3, CD4, CD8, CD25) and their correlation with HLA-DR expression befor e and after treatment with oral cetirizine, a highly selective, third generation Hi-receptor antagonist has been examined using the labeled avidin biotin (Las) system. Results. Cetirizine treatment modulated in vivo the expression of adhesion molecules LFA-1/ICAM-1 as shown in al l cases by decreased levels of their expression on keratinocytes and o n dermal endothelial cells (P < 0.001). The expression of HLA-DR On ke ratinocytes and endothelial cells was also inhibited after treatment. The numbers of infiltrating CD3-, CD4-, CD8-positive cells were reduce d, whereas there was no significant modification of CD25-positive cell s within the epidermis and the dermis. Conclusion. This open clinical trial suggests that cetirizine could be effective in treating psoriasi s: (1) for its symptomatic control on itching; (2) for its immunopharm acologic modulation of leukocyte integrins and on the immunophenotype pattern of infiltrating and resident cells, and (3) for contributing t o the clearing of the lesions clinically.