Studies Look at Experimental Test for Milk Allergy

Allergists have long advised people with milk allergies to avoid dairy products in any form. However, in a earlier study conducted in 2008, a Mount Sinai School of Medicine research team found that 75% of milk-allergic children can tolerate heated milk, such as that found in baked goods, while about 25% of milk-allergic youngsters can't tolerate any dairy products. Now it may be possible, says Hugh A. Sampson, MD, lead investigator for the two new studies presented at the conference, to determine with a blood test whether a child's allergic antibodies will react to milk that has been heated to the point that its protein structure changes.

With allergies, the body sees specific substances, known as allergens, as invaders. In people with allergies, the body's immune system produces antibodies belonging to the group of proteins called immunoglobulin E (IgE) to fight off the offensive allergens. Each specific IgE is produced in response to a specific allergen, such as the protein found in cow's milk. The IgE binds to the milk protein and sets off the immune response that causes the allergy symptoms and, in the case of some severe allergies, dangerous reactions. (Read more about this in the article on Allergies.)

The preliminary results presented by Sampson suggest that whether a milk-allergic child can tolerate heated or baked milk may be related to how many sites on the milk protein allergens his or her milk-specific IgE antibodies bind to. In a study involving a total of 52 youngsters, milk allergy-specific IgE from children who reacted to both heated and unheated milk bound to more sites on the protein molecules than did IgE antibodies from children who had allergic reactions only to unheated milk. Levels of milk-allergy specific IgE were markedly higher in children who could not tolerate either form of milk compared to IgE levels in those who were non-allergic or who passed the heated milk food challenge. Both studies also found that IgE binding correlated with severity of the children's allergic reactions.

Though the results of these studies are promising for children on restricted milk-free diets, additional research involving larger numbers of affected children is necessary before the test could be applied in clinical practice. Results from the studies presented at the conference have yet to be accepted for publication in a peer-reviewed journal, so they are considered preliminary and in need of validation. Furthermore, the current method of testing is somewhat cumbersome and would require improved technology before it would be practical for clinical use, noted Sampson.

Crystal Phend. AAAAI: Test May Okay Cookies for Most Milk-Allergic Kids. MedPage Today. Available online at http://www.medpagetoday.com/MeetingCoverage/AAAAI/18767 through http://www.medpagetoday.com. Published March 2, 2010. Accessed March 10, 2010.

American Academy of Allergy, Asthma & Immunology. Research gets closer to a test for tolerating milk products (Press Release). Available online at http://www.aaaai.org/media/news_releases/pressrelease.asp?contentid=9649 through http://www.aaaai.org. Issued February 27, 2010. Accessed March 10, 2010.

Blood Test Might Sort Out Milk Allergies: Could spot those allergic to all milk products, those who can tolerate heated milk. U.S. News and World Report. Available online at http://www.usnews.com/health/family-health/allergy-and-asthma/articles/2010/ 02/27/blood-test-might-sort-out-milk-allergies.html through http://www.usnews.com. Issued February 27, 2010. Accessed March 10, 2010.