FDA Clears Blood Test to Identify Red Meat Sensitization

July 23, 2020

It has been notoriously difficult to measure sensitization to the alpha-Gal carbohydrate.

The US Food and Drug Administration (FDA) has cleared the ImmunoCAP Specific IgE alpha-Gal Allergen Component test to help clinicians pinpoint a potentially fatal allergy often resulting from tick bites.

Cleared for in vitro diagnostic use, the test results aim to aid specialists and providers while diagnosing a patient’s sensitization to the alpha-Gal carbohydrate found in red meat and assess their risk for an anaphylactic reaction.

“Sensitization to the alpha-Gal carbohydrate has been notoriously difficult to measure in patients,” Lakiea Wright, MD, MAT, MPH, medical director of US ImmunoDiagnostics at Thermo Fisher Scientific, said in a statement. “Skin prick testing to red meats such as beef, pork, or lam often gives weak or negative results, which is why, based on clinical studies, quantification of IgE antibodies to alpha-Gal in the blood is the preferred diagnostic method. Information from these tests can help providers be more precise in their diagnosis and management recommendations.”

ImmunoCAP Specific IgE blood testing can help identify allergic sensitization to common environmental allergen and food allergens. The tests are available in most major US laboratories and can be administered to patients of any age regardless of skin condition, current medications, disease activity, or pregnancy status.

An alpha-Gal allergy can cause a severe and potentially life-threatening reaction to galactose-alpha-1, 3-galactose that is found in most red meat. Reactions to red meat can often be delayed and occur 3-8 hours after eating.

Symptoms of the food allergy range from hives and itching, to abdominal pain, nausea, vomiting, and in severe cases, can cause anaphylaxis, which can be fatal.

According to investigators, the condition can appear to those who have tolerated meat for many years as the sensitization to alpha-Gal may come from the lone star tick (Amblyomma americanum).

“The delayed nature of the reactions adds to the difficulty that clinicians and patients have in identifying the cause of the symptoms,” Thomas Platts-Mills, MD, a professor of medicine and microbiology at the University of Virginia School of Medicine, said. “This unique set of circumstances makes an accurate diagnosis critical for managing this disease.”

The ImmunoCAP Specific IgE Stinging Insect Allergen Components tests were cleared recently by the agency to improve the diagnosis of bee and wasp allergies.