Study results of DNA damage dynamics in mononuclear cells in patients with psoriasis under phototherapy impact

Objective: to investigate the effect of phototherapy on the level of DNA damage in mononuclear blood cells in patients with psoriasis using DNA Comet Assay. Material and Methods. 87 patients with psoriasis were included into the group treated by photochemotherapy; and 58 patients composed the group receiving 311 nm narrow-band phototherapy. Results. The median mean values for the median of DNA damage in the mononuclear cells under phototherapy exposure do not exceed the standard reference range. While performing a visual study of the dynamics of DNA damage level in the nucleated cells, the patients with the parameters exceeded the initial values and upper level of the reference range have been identified. UV-induced increase of DNA damage level in the mononuclear blood cells may indicate the slowing down the activity of DNA repair system processes. A predictive model for DNA damage final level from the initial values under phototherapy has been obtained, allowing identifying the patients with increased sensitivity to ultraviolet irradiation and slowing down the processes of DNA excision nucleotide repair. Conclusion. Biomonitoring of DNA damage level in the nucleated blood cells under photochemotherapy exposure and UVB-311nm demonstrates the efficacy of nucleotide excision repair processes in the studied groups of patients with psoriasis and the safety of phototherapy in compliance with medical technology.