Whole-body UVB (TL-01) or UVA-1 irradiation does not alter the levels of immunomodulatory cytokines in the serum of human volunteers.

Type:Uv phototherapy   Time:2017-09-15 10:38:17
Whole-body UVB (TL-01) or UVA-1 irradiation does not alter the levels of immunomodulatory cytokines in the serum of 
human volunteers.
BACKGROUND/PURPOSE:
Ultraviolet (UV) exposure of mammalian skin induces local and systemic immunosuppression. In mice it has been proposed 
that systemic immunosuppression is mediated by an UV-induced cytokine cascade involving systemic interleukin (IL)-4 
and IL-10 and a reduction in IL-12 activity. To investigate whether there was a parallel mechanism in humans we 
examined the effect of whole-body narrowband ultraviolet B (UVB) (311-313 nm; TL-01) and ultraviolet A (UVA)-1 (340-
400 nm) on serum cytokine levels.
METHODS/RESULTS:
In a first study, five male psoriatic subjects were whole-body irradiated with three sessions of a standard UVB (TL-
01) phototherapy regimen previously shown to cause downregulation of natural killer cell activity and T helper 1 (Th1) 
and Th2 cytokine production by peripheral blood mononuclear cells. Enzyme-linked immunoabsorbent assay (ELISA) of sera 
taken before and after the third session showed no effect of phototherapy on IL-10 and tumour necrosis factor-alpha 
(TNF-alpha). In a second study, five healthy subjects received three whole-body exposures of UVB (TL-01) and five 
other healthy subjects received three exposures of UVA-1 on alternate days (total 22 J/cm(2)). Blood samples were 
taken before the first irradiation and at 0, 4, 8, 12, 14, 24 and 48 h after the third irradiation. The sera were 
subsequently analysed for IL-10, IL-12, IL-8, IL-1beta and TNF-alpha, by ELISA. The levels of IL-1beta and TNF-alpha 
were below detection limits (<5 pg/ml), while no significant change in the levels of IL-10, IL-12 or IL-8 was detected 
as a result of either TL-01 or UVA-1.
CONCLUSIONS:
It seems unlikely that a modulation in these circulating cytokines assessed in this study accounts for systemic UV-
induced immunosuppression in human subjects.
McLoone P1, Man I, Yule S, Fluitman A, Van Loveren H, Norval M, Gibbs NK
www.kerneluvb.com----The leader manufacturer of UV Phototherapy.