IGE FOOD ALLERGEN TESTING INCONSISTENT
A commercially available immunoglobulin E-based test for food allergy gives inconsistent results in healthy ponies.
S Dupont, A De Spiegeleer, DJX Liu, L Lefére, DA van Doorn and M Hesta
IgE testing of serum samples is commercially available and is offered as a diagnostic aid for dietary allergies in equines. This method has been shown to be unreliable in humans and other species but has not previously been tested in equines. In this study blood samples were taken from 17 healthy Shetland ponies and submitted for IgE testing. Blood samples were repeated 14 days later to assess the reliability of the test. Six ponies were found to have a positive result to one or more dietary allergens with the first sample and seven ponies on the second sample; only three were positive on both occasions and only one was positive to the same allergen on both occasions. Thereafter, ponies testing positive were exposed to the dietary allergen during provocation tests. Allergens were introduced individually in the case of multiple allergens, with a washout period of one week between. Clinical parameters, including inflammatory markers were monitored in this time. The results from the first and second screening differed significantly, therefore the test was not found to be consistent. No pony showed any adverse reaction during the provocation tests with the suspected allergen.
The bottom line: IgE testing for the detection of food allergies in horses was not found to be a consistent or reliable test with positive results found in healthy horses.
Photo: Skin allergy