Long-wave UVA offers partial protection against UVB-induced immune suppression in human skin.
Ultraviolet-B (UVB, 280-320 nm) interferes with the generation of cell-mediated immunity to contact allergens applied epicutaneously on the irradiated site. To investigate whether pretreatment with UVA-1 (340-400 nm) protects against the UVB-induced immune suppression we sensitized human volunteers with diphenylcyclopropenone (DPCP) on normal buttock skin (n= 12), on UVB-irradiated buttock skin (n=21), on buttock skin pretreated with UVA-1 (n= 12), and on buttock skin pretreated with UVA-1 and thereafter irradiated with UVB (n=22). Sensitization on UVB-irradiated skin reduced the immunization rate to DPCP compared with sensitization on non-irradiated skin (p<0.01) and skin pretreated with UVA-1 (p<0.01). In contrast, the immunization rate in the group of volunteers sensitized on skin pretreated with UVA-1 before UVB irradiation was significantly higher than the immunization rate in the group of volunteers sensitized on UVB-irradiated skin alone (p<0.05). These results indicate that pretreatment with UVA-1 under certain conditions offers partial protection against the UVB-induced reduction in the immunization rates to epicutaneous allergens.
Department of Dermatology, Gentofte Hospital, University of Copenhagen, Denmark. lskov@dadlnet.dk
L
L
Skov
L
L
Villadsen
B K
BK
Ersbøll
J C
JC
Simon
J N
JN
Barker
O
O
Baadsgaard
D000328:Adult; D000485:Allergens / Q000008:administration & dosage / Q000276:immunology; D003521:Cyclopropanes / Q000008:administration & dosage / Q000276:immunology; D003877:Dermatitis, Contact / Q000517:prevention & control; D005260:Female; D006801:Humans; D007114:Immunization; D008297:Male; D012867:Skin / Q000276:immunology / Q000528:radiation effects*; D014466:Ultraviolet Rays / Q000009:adverse effects*; D014467:Ultraviolet Therapy
D000485:Allergens; D003521:Cyclopropanes; C029402:diphenylcyclopropenone