title: Characterization of IgE-mediated cutaneous immediate and late-phase reactions in nonallergic horses.
abstract: OBJECTIVE
  To characterize the response of skin of nonallergic horses following ID injection of polyclonal rabbit anti-canine IgE (anti-IgE) and rabbit IgG.
  
  
  METHODS
  6 healthy horses.
  
  
  METHODS
  Skin in the cervical area was injected ID with anti-IgE and IgG. Wheal measurements and skin biopsy specimens were obtained before and 20 minutes and 6, 24, and 48 hours after injection. Tissue sections were evaluated for inflammatory cells at 4 dermal depths. Immunohistochemical analysis for CD3, CD4, and CD8 was performed, and cell counts were evaluated.
  
  
  RESULTS
  Anti-IgE wheals were significantly larger than IgG wheals at 20 minutes and 6 and 24 hours after injection. There were significantly more degranulated mast cells after anti-IgE injection than after IgG injection. There were significantly more eosinophils at 6, 24, and 48 hours and neutrophils at 6 hours after anti-IgE injection, compared with cell numbers at those same times after IgG injection. There were significantly more eosinophils in the deeper dermis of anti-IgE samples, compared with results for IgG samples. No significant differences between treatments were detected for CD3(+), CD4(+), or CD8(+) cells.
  
  
  CONCLUSIONS
  Injection of anti-IgE antibodies was associated with the development of gross and microscopic inflammation characterized by mast cell degranulation and accumulation of inflammatory cells, particularly eosinophils and neutrophils. This pattern appeared to be similar to that of horses with naturally developing allergic skin disease, although lymphocytes were not increased; thus, ID injection of anti-IgE in horses may be of use for evaluating allergic skin diseases of horses.
authors: Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803.
authors: Michelle C
authors: MC
authors: Woodward
authors: Frank M
authors: FM
authors: Andrews
authors: Michael T
authors: MT
authors: Kearney
authors: Fabio
authors: F
authors: Del Piero
authors: Bruce
authors: B
authors: Hammerberg
authors: Cherie M
authors: CM
authors: Pucheu-Haston
mesh_terms: D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology*; D003872:Dermatitis / Q000276:immunology / Q000662:veterinary; D004804:Eosinophils / Q000276:immunology; D005260:Female; D006734:Horse Diseases / Q000139:chemically induced / Q000276:immunology / Q000473:pathology; D006736:Horses / Q000276:immunology*; D007073:Immunoglobulin E / Q000276:immunology*; D007249:Inflammation / Q000139:chemically induced / Q000473:pathology / Q000662:veterinary; D007271:Injections, Intradermal / Q000662:veterinary; D007428:Intradermal Tests / Q000662:veterinary; D007958:Leukocyte Count / Q000662:veterinary; D008297:Male; D009504:Neutrophils / Q000276:immunology; D011817:Rabbits; D012871:Skin Diseases / Q000139:chemically induced / Q000276:immunology / Q000662:veterinary; D012882:Skin Tests / Q000662:veterinary*
chemical_list: D000888:Antibodies, Anti-Idiotypic; C026408:anti-IgE antibodies; D007073:Immunoglobulin E