Immunomodulatory effect of photodynamic therapy in patients with non-melanoma skin malignancies

Photodynamic therapy (PDT) has been recognized as a noninvasive and new therapeutic approach to the effective treatment of tumors. It has been shown in studies concerning malignant cell lines and various animal tumor models that the interaction of photosensitizing substances with light leads to the release of cytotoxic substances and stimulates the immune response. The aim of our study was to analyze the immune system activation in patients with basal cell carcinoma (BCC) during the photodynamic therapy. Patients with skin malignancies were treated topically with 10% delta-aminolevulinic acid (ALA) (Medac GmbH, Wedel, Germany). The light came from an argon -pumped dye laser. Blood samples were collected from each patient twice a day: before and after the photodynamic treatment procedure. The study was conducted on lymphocytes and granulocytes from peripheral blood. In the cell culture supernatants, the concentration of tumor necrosis factor a (TNFalpha), the percentile composition of patients' lymphocytes and the chemiluminescence of neutrophils were measured. We have observed an increase in the intensity of the chemiluminescence, an increase in TNFalpha concentration and the insignificant change in lymphocyte percentile composition.