title: The CXCR3 activating chemokines IP-10, Mig, and IP-9 are expressed in allergic but not in irritant patch test reactions.
abstract: Differentiation between allergic and irritant contact dermatitis reactions is difficult, as both inflammatory diseases are clinically, histologically, and immunohistologically very similar. Previous studies in mice revealed that the chemokine IP-10 is exclusively expressed in allergic contact dermatitis reactions. In the present study, we investigated whether the mRNA expression of IP-10 and the related CXCR3 activating chemokines, Mig and IP-9 are also differentially expressed in human allergic contact dermatitis and irritant contact dermatitis reactions. Skin biopsies from allergic (13 cases) and sodium lauryl sulfate-induced irritant patch test reactions (13 cases), obtained 1-72 h after patch testing, were studied by means of an in situ hybridization technique. Results of chemokine mRNA expression were correlated with clinical scoring, histology, and immunohistochemical data including the proportion of inflammatory cells expressing CXCR3, the receptor for IP-10, Mig, and IP-9, and ICAM-1 and HLA-DR expression on keratinocytes. IP-10, Mig, and IP-9 mRNA were detected in seven of nine allergic contact dermatitis reactions after 24-72 h, but not in sodium lauryl sulfate-induced irritant contact dermatitis reactions. ICAM-1 expression by keratinocytes was only found in allergic contact dermatitis reactions and correlated with chemokine expression. Moreover, up to 50% of the infiltrating cells in allergic contact dermatitis expressed CXCR3, in contrast to only 20% in irritant contact dermatitis reactions. In conclusion, we have demonstrated differences in chemokine expression between allergic contact dermatitis and irritant contact dermatitis reactions, which might reflect different regulatory mechanisms operating in these diseases and may be an important clue for differentiation between allergic contact dermatitis and irritant contact dermatitis reactions.
authors.affiliation: Department of Dermatology, University Hospital Vrije Universiteit, Amsterdam, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Flier
authors.forename: D M
authors.initials: DM
authors.lastname: Boorsma
authors.forename: D P
authors.initials: DP
authors.lastname: Bruynzeel
authors.forename: P J
authors.initials: PJ
authors.lastname: Van Beek
authors.forename: T J
authors.initials: TJ
authors.lastname: Stoof
authors.forename: R J
authors.initials: RJ
authors.lastname: Scheper
authors.forename: R
authors.initials: R
authors.lastname: Willemze
authors.forename: C P
authors.initials: CP
authors.lastname: Tensen
mesh_terms: D054357:Chemokine CXCL10; D054371:Chemokine CXCL11; D054370:Chemokine CXCL9; D019743:Chemokines, CXC / Q000235:genetics*; D017449:Dermatitis, Allergic Contact / Q000276:immunology*; D017453:Dermatitis, Irritant / Q000276:immunology*; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000032:analysis; D036341:Intercellular Signaling Peptides and Proteins; D007371:Interferon-gamma / Q000494:pharmacology; D015603:Keratinocytes / Q000737:chemistry; D010328:Patch Tests; D012333:RNA, Messenger / Q000032:analysis*; D054367:Receptors, CXCR3; D019707:Receptors, Chemokine / Q000032:analysis
chemical_list: C515202:CXCL11 protein, human; C080810:CXCL9 protein, human; C515187:CXCR3 protein, human; D054357:Chemokine CXCL10; D054371:Chemokine CXCL11; D054370:Chemokine CXCL9; D019743:Chemokines, CXC; D006684:HLA-DR Antigens; D036341:Intercellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D054367:Receptors, CXCR3; D019707:Receptors, Chemokine; D018799:Intercellular Adhesion Molecule-1; D007371:Interferon-gamma