Influence of PUVA and UVB radiation on expression of ICAM-1 and VCAM-1 molecules in psoriasis vulgaris.

The expression of adhesion molecules Intercellular adhesion molecule-1 (ICAM-1) and Vascular cell adhesion molecule-1 (VCAM-1) is increased in lesional and in non-lesional skin of psoriatic patients, and play role in pathogenesis of the disease. PUVA and UVB therapy are important treatments of psoriasis vulgaris. It has been demonstrated that UVA and UVB therapies reduce expression of these molecules. In this investigation, phototherapy was used to treat psoriatic patients. The expression of these molecules was examined by immunohistochemical method in lesional and non-lesional skin of 10 patients with psoriasis vulgaris before and after treatment. Results showed increased expression of ICAM-1 molecules in keratinocytes, in perivascular infiltrate--lymphocytes, and in endothelial cells. The expression of VCAM-1 molecules was also increased, although with less intensity then ICAM-1. After therapy, the expression of the adhesion molecules decreased together with a marked improvement of the disease. In conclusion, study demonstrated that phototherapy improves psoriasis vulgaris probably through mechanisms acting on the adhesions molecules. Adverse reactions due to intense or long lasting UVA (PUVA) and UVB therapies are immunosuppression and damage of DNA which can lead to development of non-melanocytic skin tumors like basal cell carcinoma and squamous cell carcinoma, as well as melanoma.