Personalized Medicine for Allergies

Researchers are studying genes related to allergies, looking for new solutions to this widespread illness. Here’s what you should know.

Allergy treatments haven’t seen much progress in decades, but universities, investors, and corporations are pouring money into research on the root causes, hoping to create new, more effective therapies.

Right now, treatment for allergies is based on your medical history but not on your genetic characteristics.

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“I foresee that a lot of allergy therapies will become more and more specific and targeted, and more customizable to the individual patient,” said Andrew Long, PharmD, the lead investigational drug pharmacist at a Stanford center for allergy research.

Hundreds of millions of people around the world suffer. As many as 26 percent of American adults and 19 percent of the nation’s children have seasonal symptoms. Some 6 percent of both children and adults may have food allergies, according to the Centers for Disease Control and Prevention.  

A coalition of researchers from the Massachusetts Institute of Technology, Harvard, and Yale focused on genetic research launched an initiative to accelerate food allergy research. Interactions between “genes, gut microbes, the immune system, and food” have led to a “breakdown in tolerance,” the group wrote.

The group is using single-cell genomic analysis, looking at individual cells involved in an allergy reaction, and CRISPR genome-editing techniques, to screen for individual genes and see the role each plays in food allergy. So far, it has identified 29 targets of interest.

Interestingly, some people show evidence of an allergic response in the lab but don’t have symptoms, while other people have symptoms but don’t test as being allergic. 

Peanut allergy

Nestlé has been investing in the startup Aimmune, which has identified the proteins in peanuts that trigger reactions and are putting them as a powder in capsules called Palforzia. Patients might start taking the medication with half a milligram of the proteins and work up over six months to consuming the amount of protein in one peanut. Allergists have been making their own peanut protein concoctions to desensitize patients.

Multiple food allergies

About 70 percent of people who have an allergy to one kind of food will also be allergic to another, Long says. In standard desensitization strategies with allergy shots, it could take years to successfully cut the reaction to just one food.

The Stanford researchers are testing omalizumab (Xolair), an asthma drug, on patients with food allergies, as a way of speeding up the process and applying it to five foods at a time.

An allergic response begins when contact with the allergen triggers immunoglobulin E, or IgE. The antibody then signals two kinds of immune cells — mast cells and basophils — to release a flurry of chemicals that are designed to “fight” the allergen. (Basophils are hard to see in a blood sample, but Stanford researchers have developed a system to find them, which could make food allergy tests safer and more accurate.)

Omalizumab interferes with the second step, binding to human IgE and blocking it from triggering the other cells. The Food and Drug Administration has granted the drug breakthrough status that will hasten approval to use it for food allergies.

Most of 60 patients with multiple food allergies were able to tolerate normal servings of some foods after four months of treatment with omalizumab, according to Johns Hopkins University research. An overview of 36 studies concluded the drug significantly increased tolerance for milk, egg, and wheat.

In other research, a Harvard team led by statistical geneticist Liming Liang, PhD, found 30 genes involved in the allergic response. The goal is to identify a target that medication can alter. A European team identified 21 sites associated with childhood asthma. An international team similarly has been mapping the genetics of adult asthma.

Canadian researchers have shown that it can cut the potentially deadly anaphylactic response to peanut and egg proteins in mice up to 90 percent, by triggering a natural “off” switch, called dendritic cells, in the immune system. The same group has demonstrated it could reverse an asthmatic response in human cells in a test tube.

The ultimate goal is to develop a desensitizing shot that could work on food allergies, asthma, or even multiple sclerosis, which also involves the immune response. Research on dendritic cells remains a promising area, others say.

Cat allergy

Cat allergies are reactions to a single protein, Fel d1, in cat dander. That makes them simpler to address than allergies to dogs, which involve reactions to several proteins. But the usual solution for cat allergies, desensitization shots, often don’t work.

Instead, you can buy a cat food, Pro Plan LiveClear. The food contains antibodies from eggs that can neutralize the Fel d1 protein.

Another approach, HypoCat, is a vaccine for cats. The shot triggers them to create neutralizing antibodies to their Fel d1. It may soon be available in the United States, says Gary Jennings, chief executive officer of Saiba Animal Health, a University of Zurich spinoff.

“In school, we didn’t learn anything about allergy treatment, except antihistamines and epinephrine,” Stanford’s Long said. “But now, we’re seeing this whole new spectrum of treatments. It’ll be interesting to see how this translates into making it into a pharmacy, and into the hands of patients.”

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