title: Increased allergic immune response to Sarcoptes scabiei antigens in crusted versus ordinary scabies.
abstract: Scabies, a parasitic skin infestation by the burrowing "itch" mite Sarcoptes scabiei, causes significant health problems for children and adults worldwide. Crusted scabies is a particularly severe form of scabies in which mites multiply into the millions, causing extensive skin crusting. The symptoms and signs of scabies suggest host immunity to the scabies mite, but the specific resistant response in humans remains largely uncharacterized. We used 4 scabies mite recombinant proteins with sequence homology to extensively studied house dust mite allergens to investigate a differential immune response between ordinary scabies and the debilitating crusted form of the disease. Subjects with either disease form showed serum IgE against recombinant S. scabiei cysteine and serine proteases and apolipoprotein, whereas naive subjects showed minimal IgE reactivity. Significantly (P < 0.05) greater serum IgE and IgG4 binding to mite apolipoprotein occurred in subjects with crusted scabies than in those with ordinary scabies. Both subject groups showed strong proliferative responses (peripheral blood mononuclear cells) to the scabies antigens, but the crusted scabies group showed increased secretion of the Th2 cytokines interleukin 5 (IL-5) and IL-13 and decreased Th1 cytokine gamma interferon (IFN-gamma) in response to the active cysteine protease. These data confirm that a nonprotective allergic response occurs in the crusted disease form and demonstrate that clinical severity is associated with differences in the type and magnitude of the antibody and cellular responses to scabies proteins. A quantitative IgE inhibition assay identified IgE immunoreactivity of scabies mite antigens distinct from that of house dust mite antigens, which is potentially important for specific scabies diagnosis and therapy.
authors.affiliation: School of Health and Sport Sciences, University of the Sunshine Coast, Maroochydore DC, QLD 4558, Australia. swalton1@usc.edu.au
authors.forename: Shelley F
authors.initials: SF
authors.lastname: Walton
authors.forename: Susan
authors.initials: S
authors.lastname: Pizzutto
authors.forename: Amy
authors.initials: A
authors.lastname: Slender
authors.forename: Linda
authors.initials: L
authors.lastname: Viberg
authors.forename: Deborah
authors.initials: D
authors.lastname: Holt
authors.forename: Belinda J
authors.initials: BJ
authors.lastname: Hales
authors.forename: David J
authors.initials: DJ
authors.lastname: Kemp
authors.forename: Bart J
authors.initials: BJ
authors.lastname: Currie
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Rolland
authors.forename: Robyn
authors.initials: R
authors.lastname: O'Hehir
mesh_terms: D000328:Adult; D000485:Allergens / Q000235:genetics / Q000276:immunology*; D000818:Animals; D001053:Apolipoproteins / Q000235:genetics / Q000276:immunology; D049109:Cell Proliferation; D057056:Cysteine Proteases / Q000235:genetics / Q000276:immunology; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000473:pathology*; D007073:Immunoglobulin E / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007371:Interferon-gamma / Q000378:metabolism; D018664:Interleukin-12 / Q000378:metabolism; D015848:Interleukin-5 / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D012520:Sarcoptes scabiei / Q000276:immunology*; D012532:Scabies / Q000150:complications* / Q000276:immunology* / Q000473:pathology; D057057:Serine Proteases / Q000235:genetics / Q000276:immunology
chemical_list: D000485:Allergens; D001053:Apolipoproteins; D007074:Immunoglobulin G; D015848:Interleukin-5; D011994:Recombinant Proteins; D018664:Interleukin-12; D007073:Immunoglobulin E; D007371:Interferon-gamma; D057056:Cysteine Proteases; D057057:Serine Proteases