Prospective study in a porcine model of sarcoptes scabiei indicates the association of Th2 and Th17 pathways with the clinical severity of scabies.

BACKGROUND:Understanding of scabies immunopathology has been hampered by the inability to undertake longitudinal studies in humans. Pigs are a useful animal model for scabies, and show clinical and immunologic changes similar to those in humans. Crusted scabies can be readily established in pigs by...

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Bibliographic Details
Published in:PLOS Neglected Tropical Diseases
Main Authors: Kate E Mounsey, Hugh C Murray, Helle Bielefeldt-Ohmann, Cielo Pasay, Deborah C Holt, Bart J Currie, Shelley F Walton, James S McCarthy
Format: Article in Journal/Newspaper
Language:English
Published: Public Library of Science (PLoS) 2015
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Online Access:https://doi.org/10.1371/journal.pntd.0003498
https://doaj.org/article/dfcee5b2123d4b00bc3edb58b0d9776c
Description
Summary:BACKGROUND:Understanding of scabies immunopathology has been hampered by the inability to undertake longitudinal studies in humans. Pigs are a useful animal model for scabies, and show clinical and immunologic changes similar to those in humans. Crusted scabies can be readily established in pigs by treatment with the glucocorticoid dexamethasone (Dex). METHODOLOGY/ PRINCIPAL FINDINGS:Prospective study of 24 pigs in four groups: a) Scabies+/Dex+, b) Scabies+/Dex-, c) Scabies-/Dex+ and d) Scabies-/Dex-. Clinical symptoms were monitored. Histological profiling and transcriptional analysis of skin biopsies was undertaken to compare changes in cell infiltrates and representative cytokines. A range of clinical responses to Sarcoptes scabiei were observed in Dex treated and non-immunosuppressed pigs. An association was confirmed between disease severity and transcription of the Th2 cytokines IL-4 and IL-13, and up-regulation of the Th17 cytokines IL-17 and IL-23 in pigs with crusted scabies. Immunohistochemistry revealed marked infiltration of lymphocytes and mast cells, and strong staining for IL-17. CONCLUSIONS/ SIGNIFICANCE:While an allergic Th2 type response to scabies has been previously described, these results suggest that IL-17 related pathways may also contribute to immunopathology of crusted scabies. This may lead to new strategies to protect vulnerable subjects from contracting recurrent crusted scabies.