title: Interleukin-4 and the interleukin-4 receptor in allergic contact dermatitis.
abstract: Cutaneous immune responses involving T helper (TH) type 1 (TH1) and type 2 (TH2) T cells, characterised by secretion of interferon-gamma (Ifn-gamma) and interleukin-4 (IL-4), respectively, have both been reported in allergic contact dermatitis (ACD). We used immunohistochemistry to localize expression of IL-4 in ACD lesions and unaffected skin. Atopic dermatitis (AD) and psoriasis biopsies provided positive and negative IL-4 immunoreactivity controls. To investigate the role of IL-4 in ACD, we investigated expression of IL-4 receptors in ACD, AD and psoriatic skin. IL-4 immunoreactivity was found in cells in the dermal infiltrate in 3 out of 7 ACD lesions, but not in unaffected skin from these patients. IL-4 immunoreactivity was found in the dermal infiltrate of all lesional and unaffected AD biopsies, but in none of the psoriatic biopsies. IL-4 receptor alpha chain immunoreactivity, associated with dermal mast cells, was found in all patients. Local expression of IL-4 in ACD indicates either TH2 or TH0 immunoregulation in some allergic contact dermatitis lesions. Our findings do not support exclusive TH1 or TH2 cutaneous immune responses in ACD. Expression of IL-4 receptors by cutaneous mast cells provides a route through which local effects of IL-4 might be mediated.
authors.affiliation: Skin Treatment and Research Trust Laboratory, Imperial College School of Medicine, Chelsea and Westminster Hospital, London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Rowe
authors.forename: C B
authors.initials: CB
authors.lastname: Bunker
mesh_terms: D001706:Biopsy; D017252:CD3 Complex / Q000032:analysis; D017449:Dermatitis, Allergic Contact / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D015847:Interleukin-4 / Q000032:analysis*; D010328:Patch Tests; D019948:Receptors, Interleukin-4 / Q000032:analysis*; D012867:Skin / Q000737:chemistry / Q000473:pathology*
chemical_list: D017252:CD3 Complex; D019948:Receptors, Interleukin-4; D015847:Interleukin-4