title: An in vitro human skin test for assessing sensitization potential.
abstract: Sensitization to chemicals resulting in an allergy is an important health issue. The current gold-standard method for identification and characterization of skin-sensitizing chemicals was the mouse local lymph node assay (LLNA). However, for a number of reasons there has been an increasing imperative to develop alternative approaches to hazard identification that do not require the use of animals. Here we describe a human in-vitro skin explant test for identification of sensitization hazards and the assessment of relative skin sensitizing potency. This method measures histological damage in human skin as a readout of the immune response induced by the test material. Using this approach we have measured responses to 44 chemicals including skin sensitizers, pre/pro-haptens, respiratory sensitizers, non-sensitizing chemicals (including skin-irritants) and previously misclassified compounds. Based on comparisons with the LLNA, the skin explant test gave 95% specificity, 95% sensitivity, 95% concordance with a correlation coefficient of 0.9. The same specificity and sensitivity were achieved for comparison of results with published human sensitization data with a correlation coefficient of 0.91. The test also successfully identified nickel sulphate as a human skin sensitizer, which was misclassified as negative in the LLNA. In addition, sensitizers and non-sensitizers identified as positive or negative by the skin explant test have induced high/low T cell proliferation and IFNγ production, respectively. Collectively, the data suggests the human in-vitro skin explant test could provide the basis for a novel approach for characterization of the sensitizing activity as a first step in the risk assessment process.
authors.affiliation: Alcyomics Ltd, Bulman House, Regent Centre, Gosforth, Newcastle-upon-Tyne, NE3 3LS, UK.
authors.forename: S S
authors.identifier: http://orcid.org/0000-0002-9213-0712
authors.initials: SS
authors.lastname: Ahmed
authors.affiliation: Haematological Sciences, Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, NE2 4HH, UK.
authors.forename: X N
authors.initials: XN
authors.lastname: Wang
authors.affiliation: Haematological Sciences, Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, NE2 4HH, UK.
authors.forename: M
authors.initials: M
authors.lastname: Fielding
authors.affiliation: Haematological Sciences, Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, NE2 4HH, UK.
authors.forename: A
authors.initials: A
authors.lastname: Kerry
authors.affiliation: Haematological Sciences, Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, NE2 4HH, UK.
authors.forename: I
authors.initials: I
authors.lastname: Dickinson
authors.affiliation: Haematological Sciences, Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, NE2 4HH, UK.
authors.forename: R
authors.initials: R
authors.lastname: Munuswamy
authors.affiliation: Faculty of Life Sciences, University of Manchester, Manchester, UK.
authors.forename: I
authors.initials: I
authors.lastname: Kimber
authors.affiliation: Alcyomics Ltd, Bulman House, Regent Centre, Gosforth, Newcastle-upon-Tyne, NE3 3LS, UK.|Haematological Sciences, Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, NE2 4HH, UK.
authors.forename: A M
authors.initials: AM
authors.lastname: Dickinson
mesh_terms: D000485:Allergens / Q000633:toxicity*; D000826:Animal Testing Alternatives; D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D006241:Haptens / Q000633:toxicity*; D006801:Humans; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000378:metabolism; D007509:Irritants / Q000633:toxicity*; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D023441:Local Lymph Node Assay; D051379:Mice; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012867:Skin / Q000187:drug effects; D012882:Skin Tests; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism
chemical_list: D000485:Allergens; D006241:Haptens; D007509:Irritants; D007371:Interferon-gamma
keywords: T-cell proliferation; antigen-specific priming; in vitro alternative to animal testing; interferon-γ; local lymph node assay; potency; skin sensitization