Eczema affects about 17 percent of children in developed countries. Often, it’s a gateway to food allergy and asthma, initiating an “atopic march” toward broader allergic sensitization. There are treatments – steroid creams and a recently approved biologic – but they are expensive or have side effects. A new study in Science Immunology suggests a different approach to eczema, one that stimulates a natural brake on the allergic attack.
The skin inflammation of eczema is known to be driven by “type 2” immune responses. These are led by activated T helper 2 (TH2) cells and type 2 innate lymphoid cells (ILC2s), together known as effector cells. Another group of T cells, known as regulatory T cells or Tregs, are known to temper type 2 responses, thereby suppressing the allergic response.
Yet, if you examine an eczema lesion, the numbers of Tregs are unchanged. Interestingly, Tregs comprise only about 5 percent of the body’s T cells, but up to 50 percent of T cells in the skin. …
Eating allergenic foods during pregnancy can protect your child from food allergies, especially if you breastfeed, suggests new research. The findings, in a mouse model of allergy, underscore recent advice that pregnant or nursing mothers not avoid allergenic foods like eggs and peanuts.
The study is the first controlled investigation to demonstrate protection against food allergy from breast milk, while also pointing to a biological mechanism for inducing food tolerance. It was published online today in the Journal of Experimental Medicine.
“Whether mothers should eat allergenic foods during pregnancy or avoid them has been controversial,” says Michiko Oyoshi, PhD, of Boston Children’s Division of Allergy and Immunology, who led the study in collaboration with Richard Blumberg, MD, of Brigham and Women’s Hospital, her co-senior author.
“Different studies have found different results, in part because it’s hard in human studies to know when mothers and babies first encountered a specific food,” says Oyoshi. “But in a mouse model, we can control exposure to food.” …
The studies in question concluded that the common over-the-counter remedy can cause asthma exacerbations. Reviewing these studies, one author concluded, “Until future studies document the safety of this drug, children with asthma or at risk for asthma should avoid the use of acetaminophen.”
Worldwide, asthma affects an estimated 300 million people, and is expected to surpass 400 million by 2025, according to the World Health Organization. About 1 in 10 U.S. children have asthma, and research shows that the vast majority of them also have allergy. Could that provide a clue to its prevention?
Starting at 2 to 3 years of age, susceptible children start to become sensitized to pollens, mold spores and other airborne allergens. They begin to produce IgE antibodies, which not only trigger allergic reactions but also impair their anti-viral immune responses — potentially leading to more viral infections that can further hasten their progression to asthma.
A study last week in The New England Journal of Medicine suggests that exposing infants to peanuts can provide lasting protection against peanut allergy. But what about peanut-allergic children right now? They and their parents live a life of precautions — from pre-screening birthday party menus to segregation at the school lunch table — to avoid life-threatening consumption of even trace amounts of peanut.
Now, a multicenter study reports on a protocol combining the allergy medication omalizumab (Xolair) with controlled, gradually increasing peanut consumption. After 20 weeks, most initially allergic children could safely consume the equivalent of 8 to 10 peanuts at a time. Three months after stopping the medication, most had worked up to 16 to 20 peanuts. …
Not long ago I received a wonderful email from “Sam,” an 18-year-old young man with peanut allergy. He was participating in a clinical trial of oral immunotherapy (OIT) being carried out by colleagues here at Boston Children’s Hospital.
In OIT, patients receive initially minute doses of the food to which they are allergic. Then, over many weeks, they ingest increasing amounts, under close medical monitoring at the hospital.
OIT’s goal is to get patients to tolerate previously allergenic foods by inducing their bodies to produce Treg cells, or regulatory T cells. These are the master controllers of our immune responses, and their actions include suppressing allergic responses to foods. Food ingestion, as in OIT, will eventually induce food-specific Treg cells, but it can be a long and cumbersome process. For Sam, ingesting escalating doses of peanuts proved difficult: His email described frequent reactions ranging from stomachaches and itchiness to difficulty breathing. …
“Why obesity predisposes a person to asthma has been a real puzzle,” says Dale Umetsu, MD, PhD, who recently researched the problem with Hye Young Kim, PhD, and other colleagues in the Division of Allergy and Immunology at Boston Children’s Hospital. “Our goal was to find the connection between these two problems, which occur in both children and adults, and to explore possible new treatments.”
The team’s research indicates that obesity alters the innate immune system—the body’s first responder to infection—in several ways, resulting in lung inflammation. Published earlier this month in Nature Medicine, their work also suggests a completely new, “druggable” approach to treating patients with obesity-associated asthma, for whom standard asthma drugs often work poorly. …
Families with peanut-allergic children live in fear that their child will ingest peanuts—even minute amounts—accidentally. Now, a small pilot study published in the Journal of Allergy and Clinical Immunology offers hope.
In the year-long study, immunologist Dale Umetsu, MD, PhD, and colleagues in the Division of Allergy and Immunology at Boston Children’s Hospital were able to get some children to tolerate as many as 20 peanuts at a time. Their protocol combines a powerful anti-allergy medication with a methodical desensitization process.
While it’s not a cure, the protocol may enable children to weather trace amounts of peanuts that might lurk in baked goods or foods “manufactured in a facility that processes peanuts.” Even a small amount of peanut tolerance could be lifesaving. …