Antiproliferative, antiangiogenic and apoptotic effect of photochemotherapy (PUVA) in psoriasis patients

The aim of the study was to investigate the antiproliferative, antiangiogenic and apoptotic effect of photochemotherapy (PUVA) in psoriatic patients, and to compare it with a control group of psoriatics treated with local corticosteroid therapy. The study included 60 psoriasis patients, 30 of them allocated to PUVA therapy and local corticosteroid each. Immunohistochemical methods of staining with Ki-67, F-8 and bcl-2 antibodies were used to determine proliferative keratinocyte count, to visualize the number of blood vessels in the dermis, and to determine the number of cells exhibiting expression of the antiapoptotic oncoprotein bcl-2, respectively. In all study patients, the values of Ki-67, F-8, bcl-2 and PUVA score were recorded pre- and at six weeks post-therapeutically. Study results showed a statistically significant decrease in the epidermal proliferative keratinocyte count and dermal number of blood vessels after both therapeutic modalities (p < 0.001 both). The value of bcl-2 showed a statistically significant increase in the group of patients treated with PUVA therapy (p=0.001) and an increase in the control group, demonstrating enhanced keratinocyte apoptosis after treatment. Accordingly, study results demonstrated the antiproliferative, antiangiogenic and apoptotic effect of both PUVA and local corticosteroids. These very mechanisms appear to play a key role in the action of most antipsoriatic therapies.