title: A study for characterization of IgE-mediated cutaneous immediate and late-phase reactions in non-allergic domestic cats.
abstract: Immunoglobulin-E (IgE) mediated reactions can be induced by intradermal injection of anti-IgE antibodies in both humans and dogs. These reactions grossly and histologically mimic changes seen in naturally occurring allergic dermatitis in these species. Similar studies have not been conducted in the cat. Purified polyclonal rabbit-origin IgG specific for canine IgE (anti-IgE) and rabbit immunoglobulin G (IgG) were injected intradermally in 7 non-allergic laboratory colony cats. Wheal measurements were obtained and biopsies collected before injection and at injection sites after 20 min, 6, 24, and 48 h. Injection of anti-IgE induced an immediate wheal response which was significantly larger than that seen after injection of rabbit IgG. Anti-IgE injected skin was also significantly thicker than IgG-injected skin. This corresponded with a significant increase in number of visibly degranulated mast cells in anti-IgE samples when compared to IgG samples. Injection of anti-IgE was associated with the rapid recruitment of inflammatory cells to the injected dermis. The number of inflammatory cells and mononuclear cells were significantly elevated after the injection of anti-IgE when compared to IgG-injected skin. Both eosinophils and neutrophils were significantly increased in anti-IgE samples relative to IgG, although neutrophils were only transiently increased. The high eosinophil and relatively low neutrophil cell counts in these samples were consistent with previously documented histologic features of naturally occurring feline allergic skin disease. Immunohistochemistry identified a significantly overall increased CD1a(+) cells after the intradermal injection of anti-IgE when compared to IgG and non-injected skin. CD3(+), CD8(+) and CD4(+) were also significantly increased overall in anti-IgE injected skin relative to IgG injected skin. These data document the gross and cellular response to injection of anti-IgE in the skin of healthy, non-allergic cats and support a possible role for IgE in the development of feline allergic dermatitis.
authors.affiliation: Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA. Electronic address: shannaseals@lsu.edu.
authors.forename: Shanna L
authors.initials: SL
authors.lastname: Seals
authors.affiliation: Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Kearney
authors.affiliation: Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA.
authors.forename: Fabio
authors.initials: F
authors.lastname: Del Piero
authors.affiliation: Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA.
authors.forename: Bruce
authors.initials: B
authors.lastname: Hammerberg
authors.affiliation: Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA.
authors.forename: Cherie M
authors.initials: CM
authors.lastname: Pucheu-Haston
mesh_terms: D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000008:administration & dosage / Q000276:immunology*; D001706:Biopsy / Q000662:veterinary; D002371:Cat Diseases / Q000276:immunology*; D002415:Cats; D002452:Cell Count / Q000662:veterinary; D003876:Dermatitis, Atopic / Q000276:immunology / Q000662:veterinary*; D005260:Female; D007150:Immunohistochemistry / Q000662:veterinary; D007271:Injections, Intradermal / Q000662:veterinary; D016018:Least-Squares Analysis; D008407:Mast Cells / Q000276:immunology*; D010865:Pilot Projects
chemical_list: D000888:Antibodies, Anti-Idiotypic; C026408:anti-IgE antibodies
keywords: Allergic dermatitis; Atopic dermatitis; Cat; Cutaneous immediate-reaction; Cutaneous late-phase reaction; IgE