New Research Confirms How Allergy Shots Help Patients

Researchers at the University of Cincinnati and Cincinnati Children’s Hospital Medical Center have shown in animal studies how allergy shots work—a finding that could lead to improved protection for allergy sufferers.

The work is reported in the March 2006 edition of the

Journal of Clinical Investigation

by Fred Finkelman, MD, director of immunology, Suzanne Morris, MD, associate research professor of immunology, and Richard Strait, MD, an assistant professor of pediatrics, all of UC’s Academic Health Center

The finding, says Dr. Finkelman, confirmed what scientists have suspected for years but never proven—that allergy shots work because the injected IgG antibody, a protein that the body develops to protect itself, blocks off the invading allergen and prevents a reaction.

People who experience an allergic reaction to triggers such as food, medication, insect stings, and latex can experience “anaphylactic” shock. Anaphylaxis is a sudden, severe and potentially fatal reaction that can affect various areas of the body, including the skin, respiratory tract, gastrointestinal tract and cardiovascular system.

According to the Food Allergy Anaphylaxis Network, 30,000 people a year suffer from anaphylaxis resulting from a food allergy and end up in hospital emergency departments, and 100 to 200 people die as a result. About 50 people die each year from bee stings.

Allergy sufferers, Dr. Finkelman explains, make molecules called IgE antibodies, which sit on histamine-filled “mast cells” and are spread throughout the body. When the body is exposed to an allergen, the allergen attaches itself to the IgE on the mast cell, which then “explodes,” sending its chemical contents throughout the body and causing the allergic reaction.

“Allergists have suspected for years that allergy shots protect against anaphylaxis, at least in part, by causing your body to make more IgG antibodies, which form a protective barrier that keeps allergens from reaching the IgE antibodies,” says Dr. Finkelman.

“Until now, however, these theories were only tested using culture cells. We now know for sure that they work, because we tested them on mice.

“Now that we understand one way that allergy shots work,” Dr. Finkelman says, “we can try techniques to enhance the protection against the allergen that patients receive. We can give them longer, more permanent protection by developing therapies that produce larger amounts of IgG.

“It’s simple—the more IgG antibodies you have, the more protection you are likely to have against an allergen.”

The research was funded by the Food Allergy and Anaphylaxis Network, a Veterans Affairs Merit Award and a grant from the National Institutes of Health.