Comparison of immediate intradermal test reactivity with serum IgE quantitation by use of a radioallergosorbent test and two ELISA in horses with and without atopy.
OBJECTIVE
To compare a radioallergosorbent test and 2 ELISA with intradermal testing for the determination of environmental allergen hypersensitivity in horses with and without atopic diseases.


METHODS
Prospective clinical study.


METHODS
10 horses with recurrent urticaria, 7 with atopic dermatitis, 16 with chronic obstructive pulmonary disease, and 22 without atopy.


METHODS
History, physical examination, hemogram, serum biochemical analyses, bronchoalveolar lavage, and an intradermal test (used as the criterion standard) with a regional panel of 73 allergens were performed in all horses. Serum was analyzed by use of the 3 in vitro assays of allergen-specific IgE.


RESULTS
An ELISA based on the alpha chain of the high-affinity IgE receptor, the Fcepsilon receptor immunoglobin epsilon chain (FcepsilonRIalpha) for IgE, had the overall highest kappa statistic (0.238), positive predictive value (49%), and negative predictive value (78%). Overall agreement between the FcepsilonRIalpha-based ELISA and the intradermal test was fair. The highest kappa statistic was obtained by the FcepsilonRIalpha-based ELISA in horses with atopic dermatitis (0.330). Kappa statistics for the radioallergosorbent test and a polyclonal antibody-based ELISA agreed slightly with that of the intradermal test at best.


CONCLUSIONS
None of the 3 serum allergy tests reliably detected allergen hypersensitivity, compared with the intradermal test. The FcepsilonRIalpha-based ELISA performed significantly better overall than the other 2 tests. Low sensitivity of all 3 assays indicates the need for continued study to elucidate a more sensitive test for the determination of potentially pathogenic allergens in horses.
Lorch
G
G
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus 43210-1092, USA.
Hillier
A
A
Kwochka
K W
KW
Saville
W J
WJ
Kohn
C W
CW
LeRoy
B E
BE
D000818:Animals; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000662:veterinary*; D006734:Horse Diseases / Q000175:diagnosis / Q000276:immunology*; D006736:Horses; D006969:Hypersensitivity, Immediate / Q000175:diagnosis / Q000276:immunology / Q000662:veterinary*; D007073:Immunoglobulin E / Q000032:analysis*; D011446:Prospective Studies; D011852:Radioallergosorbent Test / Q000379:methods / Q000662:veterinary*; D012680:Sensitivity and Specificity
D007073:Immunoglobulin E