Original paper
The activity of selected lysosomal proteases of polymorphonuclear leukocytes in patients with actinic keratosis treated by photodynamic therapy (ALA-PDT)

Actinic keratosis is the most common precancerous state of the skin, observed in about 50% of the population over 40 years. The dissertation assesses the activity of chosen lysosomal proteases (cathepsin G and thiol cathepsins in free and bounded form) in patients with actinic keratosis who were given a photodynamic therapy were estimated in that work. The research was conducted on 35 clinically healthy men and women, as well as 26 patients with actinic keratosis. The research was conducted twice: before the radiation treatment and after a second cycle of ALA-PDT irradiation. The results of the research were subjected to statistical analysis. The examination conducted before the radiation treatment indicated higher activity of the examined proteases in patients with actinic keratosis, in comparison with the activity of the same enzymes in healthy individuals. After the ALA-PDT irradiation, lower activity of the examined enzymes in patients with actinic keratosis was observed, in comparison with their activity before the irradiation. However, the activity was still higher than that observed in the healthy subjects. The activity of PMNL lysosomal enzymes, especially cathepsin G, may be an indicator considered in assessment of progress in the treatment of precancerous conditions of the skin by the photodynamic method.