Effects of low-dose ultraviolet radiation on in vivo human cutaneous recall responses.
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.
Damian
D L
DL
Department of Medicine (Dermatology), Melanoma and Skin Cancer Research Institute, University of Sydney at Royal Prince Alfred Hospital, Sydney, Australia.
Barnetson
R S
RS
Halliday
G M
GM
D000485:Allergens / Q000276:immunology; D017449:Dermatitis, Allergic Contact / Q000276:immunology; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D006968:Hypersensitivity, Delayed / Q000276:immunology; D007108:Immune Tolerance; D009532:Nickel / Q000276:immunology; D012867:Skin / Q000276:immunology* / Q000528:radiation effects*; D012882:Skin Tests; D013473:Sunscreening Agents / Q000627:therapeutic use; D014373:Tuberculin / Q000276:immunology; D014466:Ultraviolet Rays
D000485:Allergens; D013473:Sunscreening Agents; D014373:Tuberculin; D009532:Nickel