title: Elicitation of contact hypersensitivity after repeated suberythemal exposures of humans to solar simulated radiation: number of epidermal Langerhans cells.
abstract: Ultraviolet radiation suppresses contact hypersensitivity (CHS). The role of epidermal Langerhans cells (LCs, CD1a(+)) in the elicitation phase of CHS is uncertain. To assess the effect of low-doses of solar simulated radiation (SSR) on LC numbers at the CHS elicitation site. 3 groups (each about 30 volunteers) were whole-body irradiated with suberythemal SSR on 2, 10 or 30 consecutive days before sensitization with diphenylcyclopropenone. Another group was not irradiated. Elicitation of CHS took place 3 weeks later with subsequent evaluation by visual scoring and spongiosis grade. CD1a(+) cells in the epidermis from the elicitation site were counted. No difference in CHS intensity between the unirradiated controls and all 3 irradiated groups was found, but a significant negative correlation between the spongiosis grade and the number of SSR exposures was shown. The number of epidermal CD1a(+) cells in the 10- and 30-day groups was reduced compared with the unirradiated group, and the 30-day group had significantly fewer than the 10-day group. Low daily doses of SSR induce suppression of CHS, leading to depletion of LCs at the CHS elicitation site. The effect on the CHS and LCs is cumulative, indicating that photoadaptation for these parameters does not develop over the 30 day irradiation period.
authors.affiliation: Department of Dermatology, Medical University of Lodz, 94-017 Lodz, Poland. lesiak_ola@interia.pl
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Lesiak
authors.forename: Mary
authors.initials: M
authors.lastname: Norval
authors.forename: Anna
authors.initials: A
authors.lastname: Sysa-Jedrzejowska
authors.forename: Anna
authors.initials: A
authors.lastname: Wozniacka
authors.forename: Jozef
authors.initials: J
authors.lastname: Kobos
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Omulecka
authors.forename: Iwona
authors.initials: I
authors.lastname: Lewy-Trenda
authors.forename: Joanna
authors.initials: J
authors.lastname: Narbutt
mesh_terms: D000328:Adult; D018949:Antigens, CD1 / Q000378:metabolism / Q000528:radiation effects; D002452:Cell Count; D003521:Cyclopropanes / Q000009:adverse effects; D003877:Dermatitis, Contact / Q000209:etiology / Q000378:metabolism*; D004307:Dose-Response Relationship, Radiation; D004817:Epidermis / Q000378:metabolism* / Q000528:radiation effects; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007165:Immunosuppression Therapy; D007801:Langerhans Cells / Q000378:metabolism* / Q000528:radiation effects; D008297:Male; D014466:Ultraviolet Rays; D014916:Whole-Body Irradiation
chemical_list: D018949:Antigens, CD1; C419393:CD1a antigen; D003521:Cyclopropanes; C029402:diphenylcyclopropenone