Effect of narrow-band ultraviolet B on the level of interleukin-17 in psoriasis patients

Background psoriasis is a chronic inflammatory skin disease that is thought to be mediated by t helper (th1) cells. interestingly, recent advances by cellular immunologists have led to the identification of a new distinct type of t cell called th17 cells that may play an essential pathogenic role in psoriasis. objective the present study was planned to study the effect of narrow-band ultraviolet b (nb-uvb) on serum levels of interleukin-17 (il-17) in psoriasis patients. patients and methods in this study, we estimated serum levels of il-17 in 20 psoriatic patients before and after 36 sessions of nb-uvb and in 10 healthy controls using enzyme-linked immunosorbent assay, correlating their levels with disease severity, which was calculated using the psoriasis area severity index. results the mean serum levels of il-17 were significantly elevated in patients with psoriasis in comparison with those in normal controls. moreover, there was significant elevation in mean serum il-17 levels of psoriatic patients before treatment compared with those after treatment. conclusion psoriasis is a th1 and th17-mediated inflammatory skin disease, and nb-uvb has a significant inhibitory effect on both serum levels of il-17 and psoriasis area severity index scores.