Effects of low‐dose ultraviolet radiation on in vivo human cutaneous recall responses

Abstract

Relatively few studies have examined the effects of low-dose ultraviolet (UV) radiation on in vivo human cutaneous immunity, or the ability of sunscreens to prevent UV-induced immunosuppression. We have studied the effects of solar-simulated UV radiation on nickel contact hypersensitivity (CHS) in nickel-allergic volunteers, and on delayed type hypersensitivity responses in Mantoux-positive volunteers. Nickel CHS and Mantoux responses were significantly suppressed by acute, suberythemal UV exposures equivalent to less than 8 min summer sunlight. Both UVA and UVB wavebands were immunosuppressive, but UVA-induced immunosuppression was transient, whereas UVB had a more sustained effect. Dose-responses for UV immunosuppression were determined using the nickel method, enabling calculation of in vivo sunscreen immune protection factors in a manner analogous with sun protection factor measurement. Sunscreens were found to confer significantly less protection against UV-induced immunosuppression than against UV-induced erythema.

Randomized controlled trial of oral omega-3 PUFA in solar-simulated radiation-induced suppression of human cutaneous immune responses

“…We observed a UVR dose-dependent increase in the percentage of photoimmunosuppression of the nickel CHS response that reached 43% at the highest SSR dose used. Our findings were consistent with those of Damian et al (20) who reported that immunosuppression can be induced by low doses of SSR. The current study suggested that n23 PUFAs are protective against photoimmunosuppression.…”

“…UVR reduces CMI in human skin in a dose-dependent manner (20,21), and this effect can be quantified by measuring the inhibition of immune responses to recall antigens applied topically or injected into the skin (22). Nickel is frequently used as the recall antigen because contact hypersensitivity (CHS) to this metal is common in the population and affects w15% of women and w5% of men (23).…”

Exposure to ultraviolet-B and risk of developing rheumatoid arthritis among women in the Nurses’ Health Study

“…Previous studies have shown that people living in the northeast USA have a higher risk of RA, 1 2 which may be due to lower ultraviolet (UV) light exposure. In experimental studies, UV radiation acts as an immunosuppressant by up-regulating Th2 cells and down-regulating Th1 cells, [3][4][5] inducing interleukin-10 production, an anti-inflammatory cytokine, as well as the production of T-regulatory cells. [6][7][8][9][10] UV-B (from 290 to 315 nm) exposure causes both sunburn and skin damage and stimulates cutaneous synthesis of vitamin D and could thus decrease risk of RA through increasing vitamin D, which has known immunomodulating effects.…”

Measurement of Sunscreen Immune Protection Factors in Humans: A Consensus Paper

“…The UK group has shown that susceptibility to immunosuppression (induction of CHS) is skin type dependent (Kelly et al, 2000), with skin types I/II being more readily suppressed than skin types III/IV. But the Australian group found no relationship between susceptibility to sunburn, which is roughly skin type dependent, and susceptibility to suppression of the elicitation of CHS to nickel (Damian et al, 2001).…”