Repeated Doses of UVR Cause Minor Alteration in Cytokine Serum Levels in Humans

The aim of our study was to compare serum concentration of IL-1beta, IL-6, IL-8, IL-10, and TNF-alpha in 105 healthy volunteers before and after exposure to UVR: 25 subjects (10 days of UVB), 55 (10 days of UVB or solar-simulated radiation, followed by acute UVB dose), and 25 (local high dose of UVB). In all the individuals blood samples were analyzed before and after final irradiation by chemiluminescence assay. After 10 days of UVB irradiation a statistically significant increase in serum concentration only in IL-8 (P<.05) and strong tendency in TNF-alpha (P=.05) were observed. The applied schedules of irradiation have minor impact on serum cytokine level and still a threshold dose of UVR causing systemic immune impairment is unknown.