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Children Can Complete Treatment For Peanut Allergies And Achieve Long-term Tolerance, Studies Suggest

November 7th, 2009

From ScienceDaily.com:

A carefully administered daily dose of peanuts has been so successful as a therapy for peanut allergies that a select group of children is now off treatment and eating peanuts daily, report doctors at Duke University Medical Center and Arkansas Children’s Hospital.

“It appears these children have lost their allergies,” says Wesley Burks, MD, Chief of the Division of Pediatric Allergy and Immunology at Duke. “This gives other parents and children hope that we’ll soon have a safe, effective treatment that will halt allergies to certain foods.”
Long-term tolerance in children with peanut allergies was documented for the first time by the presence of key immunologic changes, according to researchers at Duke and Arkansas Children’s Hospital who presented their findings at the American Academy of Asthma and Immunology meeting in Washington, DC March 15.
This procedure is not currently recommended for patients as it has not been fully tested, and it should never be attempted without full medical supervision.
Tests of several immunologic indicators suggest the body builds tolerance quickly.
“At the start of the study, these participants couldn’t tolerate one-sixth of a peanut,” Burks said. “Six months into it, they were ingesting 13 to 15 peanuts before they had a reaction.”
About four million Americans have food allergies, and allergies to tree nuts and peanuts are the most common. Life-threatening reactions can occur from exposure to even a trace amount of peanuts, and nearly half of the 150 deaths attributed to food allergies each year are caused by peanut allergies.
Duke and Arkansas Children’s Hospital began enrolling patients in studies five years ago to determine if incremental doses of peanut protein could change how the body’s immune system responds to its presence. The doses start as small as 1/1000 of a peanut. Eight to 10 months later, the children are ingesting the equivalent of up to 15 peanuts per day. The children stay on that daily therapy for several years and are monitored closely.
Nine of the 33 children participating in the study have been on maintenance therapy for more than 2.5 years. After a series of food challenges, four of those children were taken off the treatment and continue to eat peanuts. Some have been off treatment for more than a year. Doctors keep tabs on any potential changes in their immune system via skin, blood and immune studies.
One of the tests used in the study looks at immunoglobulin E (IgE), a protein the body makes in response to peanut allergens. “If you have it, you’re likely allergic, if you don’t, you aren’t,” explained Burks. Children in this study generally started with IgE levels greater than 25. “At the end of the study, their peanut IgEs were less than 2 and have remained that way since we stopped the treatment,” he said.
Because the pool of children now off treatment is so small, Burks says it’s hard to say whether these children simply outgrew their allergies or if the therapy did something to enhance that outcome. The next step is a blinded study in which children on treatment are compared to a control group. First year results were presented at the meeting by Stacie M. Jones, MD, a pediatric allergist at Arkansas Children’s Hospital. So far, the oral immune therapy appears to be working.
“We see initial desensitization effects of the treatment are real,” Burks says. “Those children are now able to eat up to 15 peanuts with no reaction, but the children not on treatment have symptoms early on in the study.”
Despite the news, Burks insists this research is still ongoing and cautions parents and professionals against trying any version on their own. “In my clinic, I would do the same things I’ve always done. Once diagnosed with a food allergy, I would recommend they avoid the food. We have to wait for the studies to show the treatment is safe, and to see desensitization start to work. We also want to know the therapy works long term.”
Burks also cautions that some people are too sensitive to peanut allergens to be able to undergo the therapy.

Gut Worms May Protect Against House-dust Mite Allergy

September 29th, 2009

Dr. Perlmutter’s comment: We have lived symbiotic with a variety of organisms eons. Consider this as just another indication that the sterilizaton of our environment may have unpredicted consequences.

From ScienceDaily.com:

A study conducted in Vietnam has added further weight to the view that parasitic gut worms, such as hookworm, could help in the prevention and treatment of asthma and other allergies.

Led by Dr Carsten Flohr, a Clinical Scientist from The University of Nottingham, and Dr Luc Nguyen Tuyen from the Khanh Hoa Provincial Health Service in central Vietnam, the study is the largest double-blind placebo controlled clinical trial to date looking at the potential links between hookworm and other gut worm infections and allergic conditions such as asthma and eczema.

Thanks to improved hygiene practices parasitic worms have been mostly eradicated among human populations living in developed countries. However, experts believe that over millions of years of co-evolution worms have found methods to dampen down host immune responses to prolong their own survival inside humans. This relationship seems to have become so intertwined that without gut worms or other parasites, our immune system can become unbalanced, which in turn could contribute to the development of asthma and other allergies. At the same time, it is important to remember that gut parasites can cause severe disease and are a major cause of iron-deficiency anaemia in developing countries.

Dr Flohr’s study was conducted in a rural area of central Vietnam where two out of three children have hookworm and other gut parasite infections and where allergies are extremely rare. More than 1,500 schoolchildren aged 6-17 took part.

The team investigated whether repeated tablet treatments to clear the body of gut worms made it more likely for children to develop allergic conditions. While the treatment did not demonstrate an effect on asthma or eczema, the treated children had a significantly increased risk of having a positive allergy skin test to house-dust mites and cockroach. This suggests that gut worms have the potential to tone down human immune responses and so further research is now needed to identify precisely how gut worm infection can prevent allergic sensitisation.

Dr Carsten Flohr of The University of Nottingham adds: “The next step is to understand exactly how and when gut parasites programme the human immune system in a way that protects against allergic sensitisation, and for such studies, follow-up from birth will be essential.”

As up to 80 per cent of people with asthma also have allergies to house-dust mites and other environmental allergens, additional research in this area could aid the creation of new treatments that work in the same way as gut parasites, by dampening down or rebalancing the immune system so that the body does not respond to allergens and trigger asthma attacks.

Dr Elaine Vickers, Research Relations Manager at Asthma UK, says: “Asthma affects more than five million people in the UK, with a person being admitted to hospital every seven minutes following an asthma attack. The prospects of further studies in this area are therefore very exciting as we could see groundbreaking treatments for asthma and other allergies developed as a result. It’s now vital that we see more funding being invested in this important area of research, so that we can increase our understanding of the link between gut parasites and the development of allergies from birth.”

Co-applicants on the Asthma UK research grant that funded the work were Professors John Britton, David Pritchard, and Hywel Williams. The Nottingham team collaborated with researchers from the Wellcome Trust Major Overseas Programme at the Oxford University Clinical Research Unit Hospital for Tropical Diseases in Ho Chi Minh City, where Dr Flohr was based for his work. Additional funding was received through the Bastow Award from the Special Trustees for Nottingham University Hospitals. Dr Flohr’s salary was provided by University College, University of Oxford, for two years and by the Wellcome Trust UK for a further nine months.

Folic Acid Treatment May Help Allergies, Asthma

May 6th, 2009

From MedicalNewsToday.com
Folic acid, or vitamin B9, essential for red blood cell health and long known to reduce the risk of spinal birth defects, may also suppress allergic reactions and lessen the severity of allergy and asthma symptoms, according to new research from the Johns Hopkins Children’s Center.

In what is believed to be the first study in humans examining the link between blood levels of folate – the naturally occurring form of folic acid – and allergies, the Hopkins scientists say results add to mounting evidence that folate can help regulate inflammation. Recent studies, including research from Hopkins, have found a link between folate levels and inflammation-mediated diseases, including heart disease. A report on the Hopkins Children’s findings appears online ahead of print in the Journal of Allergy & Clinical Immunology.

Cautioning that it’s far too soon to recommend folic acid supplements to prevent or treat people with asthma and allergies, the researchers emphasize that more research needs to be done to confirm their results, and to establish safe doses and risks.

Reviewing the medical records of more than 8,000 people ages 2 to 85 the investigators tracked the effect of folate levels on respiratory and allergic symptoms and on levels of IgE antibodies, immune system markers that rise in response to an allergen. People with higher blood levels of folate had fewer IgE antibodies, fewer reported allergies, less wheezing and lower likelihood of asthma, researchers report.

“Our findings are a clear indication that folic acid may indeed help regulate immune response to allergens, and may reduce allergy and asthma symptoms,” says lead investigator Elizabeth Matsui, M.D. M.H.S., pediatric allergist at Hopkins Children’s. “But we still need to figure out the exact mechanism behind it, and to do so we need studies that follow people receiving treatment with folic acid, before we even consider supplementation with folic acid to treat or prevent allergies and asthma.”

The current recommendation for daily dietary intake of folic acid is 400 micrograms for healthy men and non-pregnant women. Many cereals and grain products are already fortified with folate, and folate is found naturally in green, leafy vegetables, beans and nuts.

Other findings of the study:
People with the lowest folate levels (below 8 nanograms per milliliter) had 40 percent higher risk of wheezing than people with the highest folate levels (above 18 ng/ml).

People with the lowest folate levels had a 30 percent higher risk than those with the highest folate levels of having elevated IgE antibodies, markers of allergy predisposition.

Those with the lowest folate levels had 31 percent higher risk of atopy (allergic symptoms) than people with the highest folate levels.

Those with lowest folate levels had 16 percent higher risk of having asthma than people with the highest folate levels.
Blacks and Hispanics had lower blood folate levels -12 and 12.5 nanograms per milliliter, respectively – than whites (15 ng/ml), but the differences were not due to income and socio-economic status.

The Hopkins team is planning a study comparing the effects of folic acid and placebo in people with allergies and asthma.

Asthma affects more than 7 percent of adults and children in the United States, and is the most common chronic condition among children, according to the Centers for Disease Control and Prevention. Environmental allergies are estimated to affect 25 million Americans, according to the CDC.

Telling Food Allergies From False Alarms

February 5th, 2009

From nytimes.com
For Ingelisa Keeling, a Houston mother of three children with multiple allergies, mealtime was a struggle. Nuts, eggs, wheat, beef, peas and rice were all off limits — banned by the children’s allergist.

But recently, Mrs. Keeling learned that her family’s diet need not be so restrictive. Although her children do have real allergies — to peanuts, milk and eggs, among other foods — extensive testing at a major allergy center showed that they were not in fact allergic to many of the foods they had been avoiding. Her 2-year-old son, who had been living on a diet primarily of potatoes, fruit and hypoallergenic formula, has resumed eating wheat, bananas, beef, peas, rice and corn.

“His diet had become so, so restricted that nutrition had become a real concern,” said Mrs. Keeling, who traveled to specialists at National Jewish Health in Denver last summer for answers about her children’s diet and eczema problems. Among other findings, she learned that neither of her younger children was really allergic to wheat.

“That’s the big one,” she said. “Wheat is in everything, so it makes life a whole lot easier.”

Doctors say that misdiagnosed food allergies appear to be on the rise, and countless families are needlessly avoiding certain foods and spending hundreds of dollars on costly nonallergenic supplements. In extreme cases, misdiagnosed allergies have put children at risk for malnutrition.

And avoiding food in the mistaken fear of allergy may be making the overall problem worse — by making children more sensitive to certain foods when they finally do eat them.

More than 11 million Americans, including 3 million children, are estimated to have food allergies, most commonly to milk, eggs, peanuts and soy. The prevalence among children has risen 18 percent in the past decade, according to the Centers for Disease Control and Prevention. While the increase appears to be real, so does the increase in misdiagnosis.

The culprit appears to be the widespread use of simple blood tests for antibodies that could signal a reaction to food. The tests have emerged as a quick, convenient alternative to uncomfortable skin testing and time-consuming “food challenge” tests, which measure a child’s reaction to eating certain foods under a doctor’s supervision.

While the blood tests can help doctors identify potentially risky foods, they aren’t always reliable. A 2007 issue of The Annals of Asthma, Allergy & Immunology reported on research at Johns Hopkins Children’s Center, finding that blood allergy tests could both under- and overestimate the body’s immune response. A 2003 report in Pediatrics said a positive result on a blood allergy test correlated with a real-world food allergy in fewer than half the cases.

“The only true test of whether you’re allergic to a food or not is whether you can eat it and not react to it,” said Dr. David Fleischer, an assistant professor of pediatrics at National Jewish Health. In one recent case there, doctors treated a young boy who had been given a feeding tube because blood tests indicated he was allergic to virtually every food. Food challenge testing allowed doctors to quickly reintroduce 20 foods into his diet, and they expect more to be added.

Blood tests may be unreliable because they fail to distinguish between similar proteins in different foods. A child who is allergic to peanuts, for instance, might test positive for allergies to soy, green beans, peas and kidney beans. Children with milk allergies may test positive for beef allergy.

The most important question in diagnosing food allergy is whether the child has tolerated the food in the past, Dr. Fleischer says. While some severe allergies are obvious, parents given a positive blood test result should seek advice from an experienced allergist who performs medically supervised food challenge testing.

Even when a food allergy has been confirmed, parents should have children retested, because many allergies are outgrown, particularly in the cases of milk, eggs, soy and wheat.

Doctors’ groups are also starting to acknowledge that some of their own policies may have contributed to overtesting and misdiagnoses. A committee for the American Academy of Asthma Allergy and Immunology is considering revised guidelines recommending earlier introduction of foods like eggs, peanuts and shellfish, which in the past have been delayed until age 2 or 3. A 2008 study of 10,000 British children, reported in The Journal of Allergy and Clinical Immunology, found that early exposure to peanuts lowered allergy risk.

Just as an allergy indicates oversensitivity to certain foods, it may be that doctors and parents have become oversensitive to food allergies. In an essay in The British Medical Journal in December, Dr. Nicholas A. Christakis, a professor at Harvard Medical School, argues that an “overreaction” to allergy is leading to unnecessary testing and false positives.

“If the kid has been doing fine, I would advise parents not to get allergy testing, because the results are more likely to be false positives than true positives,” Dr. Christakis said in an interview. “If they do think they need allergy testing, be extremely measured and go to reputable people.”