title: Evaluation of an IgE ELISA with Culicoides spp. extracts and recombinant salivary antigens for diagnosis of insect bite hypersensitivity in Warmblood horses.
abstract: Insect bite hypersensitivity (IBH) in horses represents an immunoglobulin E (IgE)-mediated hypersensitivity to salivary antigens from biting midges (Culicoides spp.). The aim of this study was to evaluate and compare the performances of IgE ELISAs using recombinant Culicoides spp. Obsoletus group salivary gland antigens or crude whole body extracts ('ObsWBE'), C. nubeculosus recombinant proteins (Culn1, 3, 4, 5, 7, 8 and 10) and Obsoletus group recombinant proteins (Culo1 and 2). IgE levels were measured in plasma of 343 Warmblood horses classified as IBH-affected (n=167) and IBH-unaffected (n=176) according to the owners' descriptions. IBH-affected horses were subdivided based on the severity of their clinical signs at sampling and whether or not their IBH history was considered to be classical. The accuracies of the tests increased when clinical signs at sampling were more pronounced or when the IBH history could be considered as classical. A combination of IgE levels against the three best performing Culicoides spp. recombinant proteins (Culn4, Culo1 and Culo2) and ObsWBE resulted in the best performing test. When IBH-affected horses showing a classical history of the disease and severe clinical signs were compared with IBH-unaffected horses, the Youden's index at the optimal cut-off for the three tests in combination was 0.67. This optimal cut-off had a sensitivity of 70%, a specificity of 97% and a total accuracy of 92%. The performance of the IgE ELISA was affected by the severity of IBH clinical signs at sampling and was improved when IgE levels against several recombinant proteins were combined.
authors.affiliation: Department of Biosystems, Katholieke Universiteit Leuven, BE-3001 Heverlee, Belgium. Electronic address: liesbet.peeters01@gmail.com.
authors.forename: L M
authors.initials: LM
authors.lastname: Peeters
authors.forename: S
authors.initials: S
authors.lastname: Janssens
authors.forename: B M
authors.initials: BM
authors.lastname: Goddeeris
authors.forename: K
authors.initials: K
authors.lastname: De Keyser
authors.forename: A D
authors.initials: AD
authors.lastname: Wilson
authors.forename: C
authors.initials: C
authors.lastname: Kaufmann
authors.forename: A
authors.initials: A
authors.lastname: Schaffartzik
authors.forename: E
authors.initials: E
authors.lastname: Marti
authors.forename: N
authors.initials: N
authors.lastname: Buys
mesh_terms: D000485:Allergens / Q000235:genetics / Q000276:immunology*; D000818:Animals; D002519:Ceratopogonidae / Q000502:physiology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods* / Q000662:veterinary; D006734:Horse Diseases / Q000175:diagnosis* / Q000276:immunology; D006736:Horses; D006967:Hypersensitivity / Q000175:diagnosis / Q000276:immunology / Q000662:veterinary*; D007073:Immunoglobulin E / Q000097:blood; D007299:Insect Bites and Stings / Q000175:diagnosis / Q000276:immunology / Q000662:veterinary*; D019476:Insect Proteins / Q000235:genetics / Q000276:immunology*; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D012469:Salivary Glands / Q000378:metabolism; D017422:Sequence Analysis, DNA / Q000662:veterinary
chemical_list: D000485:Allergens; D019476:Insect Proteins; D011994:Recombinant Proteins; D007073:Immunoglobulin E
keywords: Allergen-specific IgE ELISA; Culicoides spp.; Equine; Insect bite hypersensitivity; Warmblood