Tag: food allergies

Categories : AllergiesTags :

Immunotherapy Lets Children with High-threshold Allergy Safely Eat Peanut Butter

On By ModernMedia
Photo by Corleto on Unsplash

Children with high-threshold peanut allergy who ate gradually larger doses of store-bought peanut butter achieved significantly higher and long-lasting rates of desensitisation compared to those who avoided peanuts, according to a new study led by researchers at the Icahn School of Medicine at Mount Sinai.  

Results of the trial appear in NEJM Evidence. 

“Our study results suggest a safe, inexpensive and effective pathway for allergists to treat children with peanut allergy who can already tolerate the equivalent of at least half a peanut, considered a high-threshold peanut allergy,” said Scott Sicherer, MD, director of a food allergy institute at Mount Sinai and lead author of the paper. “Our findings open the gateway to personalised threshold-based treatments of food allergy and will encourage additional studies that delve deeper into peanut and other foods for this approach that might be a game-changer for the majority of people with food allergies.”   

The most common approach to a food allergy is to avoid the food, but in recent years peanut oral immunotherapy – medically supervised, very gradual daily feeding of increasing amounts of pharmaceutical-grade peanut protein – has become an option for individuals with peanut allergies.. However, studies that led to Food and Drug Administration approval of an injected biologic and oral peanut immunotherapy have specifically focused on people who react to very small amounts of food allergens, such as half a peanut or less (considered a low-threshold peanut allergy).

“Years ago, when people with milk and egg allergies were advised to undertake strict avoidance, our team initiated studies that found most people with milk and egg allergies could tolerate these foods in baked goods, which changed the global approach to these allergies,” said Julie Wang, MD, Professor of Pediatrics at the Icahn School of Medicine, clinical researcher at the Jaffe Food Allergy Institute, and co-senior author of the paper. “The research team recognised that more than half of people with peanut allergy can tolerate half a peanut or more, and thought that this group of people might be treatable if we took a different approach to peanut oral immunotherapy. We were thrilled to find that this treatment strategy was even more successful than we had anticipated.”  

To test this hypothesis, the study team recruited 73 children ages 4 to 14 years old. Study participants were assigned, at random, to either test the new treatment strategy or continue avoiding peanuts. The children in the peanut-ingestion group began with a minimum daily dose of 1/8 teaspoon of peanut butter and gradually increased their dose every eight weeks over the course of 18 months, ending at one tablespoon of peanut butter or an equivalent amount of a different peanut product. All dose increases took place under medical supervision. None of the study participants in the peanut-ingestion group had severe reactions or needed epinephrine during home dosing  and only one received epinephrine during a supervised dosing visit.  

Following the treatment regimen, children from the peanut-consuming cohort participated in a feeding test, carefully supervised by the study team, to evaluate how much peanut they could eat without an allergic reaction. All 32 children from the peanut-consuming group who participated in the feeding test could tolerate the maximum amount of 9 grams of peanut protein, or three tablespoons of peanut butter. By contrast, only three of the 30 children from the avoidance group who underwent the feeding test after avoiding peanuts for the duration of the study could tolerate this amount.  

Because the trial took place during the COVID-19 pandemic and some families preferred avoiding close encounters indoors, some did not return to the study site for the feeding test. Using a common statistical technique to account for the children who missed the feeding test, the team reported that 100 percent of the ingestion group and 21 percent of the avoidance group tolerated an oral food challenge that was at least two doses more than they could tolerate at the beginning of the study.  

To test if the response to treatment was durable, children in the peanut-ingestion group who could tolerate nine grams of protein during the feeding test went on to consume at least two tablespoons of peanut butter weekly for 16 weeks and then avoided peanuts entirely for eight weeks. Twenty-six of the 30 treated children who participated in a final feeding test after the eight-week abstinence period continued to tolerate nine grams of peanut protein, indicating that they had achieved sustained unresponsiveness to peanuts. The three participants from the avoidance group who could eat nine grams of peanut protein without reaction at the earlier food test were considered to have developed natural tolerance to peanuts. A comprehensive analysis of data collected from all 73 study participants revealed that 68.4 percent of the peanut-ingestion group achieved sustained unresponsiveness, while only 8.6 percent of the avoidance group developed a natural tolerance.   

“These study results are very exciting and a huge step forward in personalizing food allergy treatment,” concluded Dr. Sicherer, the Elliot and Roslyn Jaffe Professor in Pediatric Allergy and Immunology at Mount Sinai. “My hope is that this study will eventually change practice to help these children and encourage additional research that includes this approach for more foods.”  

In addition to expanding the work to more foods and validation studies of their approach, the Mount Sinai study team aims to determine a better way of identifying individuals with higher thresholds, because the best way to do so currently requires a feeding test that is bound to cause an allergic reaction.  

Source: The Mount Sinai Hospital / Mount Sinai School of Medicine

Categories : AllergiesTags :

New Clues to the Mechanism Behind Food Tolerance and Allergies

On By ModernMedia
Photo by Corleto on Unsplash

How the gut decides which food to tolerate and which food to respond to as an allergen has long puzzled scientists. Now, new research identifies specific gut cell types that communicate with T cells – prompting them to tolerate, attack, or simply ignore – and explains how these opposing responses are triggered.

The findings, published in Science, give scientists a new understanding of how the intestinal immune system keeps the gut in balance, and may ultimately shed light on the root causes and mechanisms of food allergies and intestinal diseases.

“The big question is, how do we survive eating?” says lead author Maria C.C. Canesso, a postdoctoral fellow in the laboratories of Daniel Mucida and Gabriel D. Victora. “Why do our bodies normally tolerate food, and what goes wrong when we develop food allergies?”

Gut decisions

The intestinal immune system is complicated machinery. Tolerance to food begins with antigen presenting cells, or APCs, instructing T cells to stand down. This signal gives rise to pTregs, a special type of T cell that calms the immune response to food particles, and kicks off a cascade of activity involving additional immune cells that reinforce the message. But without knowing which specific APCs run the show, it’s difficult to tease out the ins and outs of the body’s eventual tolerance to food and intolerance to pathogens.

“There are so many types of antigen-presenting cells,” Canesso says. “Pinpointing which ones are doing what is a longstanding technical challenge.”

She began exploring this conundrum as a PhD student in the Mucida lab, which focuses on how the intestine balances defense with tolerance. During her postdoc, Canesso also joined the Victora lab, which developed a technology known as LIPSTIC that helps scientists catalogue cell-to-cell interactions, particularly among immune cells.

“The technological advances made by the Victora lab allowed us to understand immune cell dynamics that would not have been possible using existing tools,” says Mucida, head of the Laboratory of Mucosal Immunology.

After optimising LIPSTIC for the task, Canesso and colleagues succeeded in pinpointing those APCs that promote tolerance – a process primarily handled by two types: cDC1s and Rorγt+ APCs. These cells capture dietary antigens from ingested food and present them to T cells, giving rise to the pTregs that ensure food tolerance.

“When we first developed LIPSTIC, we were aiming to specifically measure the interactions between B and T cells that promote antibody responses to vaccines,” says Victora, head of the Laboratory of Lymphocyte Dynamics. “It was to Maria’s credit that she was able to adapt this to settings so different from those it was originally intended for.”

They also uncovered how infections of the intestines can cause interference, demonstrating in mice that the parasitic worm Strongyloides venezuelensis shifts the balance away from tolerance promoting APCs and toward those that promote inflammation. Indeed, mice infected with this worm during a first exposure to a dietary protein display reduced tolerance towards this protein, and signs of allergy when challenged.

Finally, the team characterised the molecular signals underpinning these immune shifts, identifying key cytokines and pathways that influence how APCs present antigens and modulate immune responses. For example, the infection induced a surge in pro-inflammatory cytokines such as IL-6 and IL-12, which have been shown to nudge APC activity toward inflammatory outcomes. This inflammatory environment appears to override the immune system’s tolerance mechanisms. “The worm infection induces this an expansion of non-tolerogenic APCs that help deal with the infection, outnumbering the tolerance-related APCs,” Canesso says.

From food to food allergies

Together, the findings illuminate how the immune system maintains food tolerance and, in the case of parasitic infections, highlights the specific immune mechanisms that can go awry. “It’s important to note that our findings do not suggest that worm infections trigger food allergies,” clarifies Mucida, head of the Laboratory of Mucosal Immunology. “They reduce tolerance mechanisms while the immune response focuses on dealing with the worms.”

While these findings aren’t directly relevant to food allergies, they do lay some groundwork for further investigation into food intolerance. “If food allergies are derived from dysregulation on intestinal APCs inducing tolerance and protective responses to infections, perhaps we could one day modulate those APCs specifically to prevent food allergies,” Canesso says.

Next up, Canesso plans to shift her focus toward early life, exploring how maternal-neonatal interactions shape food intolerance. “Most allergies develop early in life,” she says. “I want to focus on how breast milk and maternal exposure to dietary antigens may influence a baby’s immune system, potentially shaping their risk of developing food allergies.”

Source: Rockefeller University

Categories : AllergiesTags :

Better Allergy Diagnosis with Mast Cell Activation Testing

On By ModernMedia
Photo by Corleto on Unsplash

Researchers at the University of Bern and Bern University Hospital have developed a test to simplify the diagnosis of allergies by testing mast cells. Its effectiveness has now been confirmed in clinical samples from children and adolescents suffering from a peanut allergy. The results, recently published in the European Journal for Allergy and Clinical Immunology (Allergy), could fundamentally improve the clinical diagnosis of allergies in future.

Food allergies are a major health problem worldwide. In some countries, up to 10% of the population is affected, mainly young children. Peanut allergy, in particular, is one of the most common diseases and often manifests itself in severe, potentially life-threatening reactions. The stress of food allergies not only affects the individuals concerned, but also has far-reaching consequences for their families, the health system and the food industry. The oral food challenge test, in which people consume the allergen (such as peanut extract) under supervision to test the allergic reaction, is still considered the gold standard in diagnosis. However, the method is complex and carries health risks. The allergen skin prick test and blood test are often not very accurate, which can lead to misdiagnoses and unnecessary food avoidance. 

A team of researchers led by Prof Dr Alexander Eggel and Prof Dr Thomas Kaufmann from the University of Bern, developed an alternative test in 2022. It mimics the allergic reaction in a test tube and thus offers an attractive alternative to standard tests. The Bern researchers have now investigated the effectiveness of the test on samples from children and adolescents with confirmed peanut allergy and a healthy control group in a clinical study in collaboration with partners from the Hospital for Sick Kids in Toronto, Canada. They were able to show that the new test has a higher diagnostic accuracy than the methods used so far.

Mast cell activation test as appropriate alternative

“The most common food allergies are type I allergies. They develop when the body produces immunoglobulin E (IgE) antibodies in response to substances that are actually harmless (allergens),” explains Alexander Eggel. These antibodies bind to specific receptors on the mast cells, which are immune cells that play an important role in allergic reactions and inflammation. They are mainly located in the tissue, for example, in the intestinal mucosa, and are prepared for and sensitised to the allergen by binding to the antibodies. Upon renewed contact with the allergen, it binds directly to the mast cells loaded with antibodies, activating them and triggering an allergic reaction.

“In the Hoxb8 mast cell activation test (Hoxb8 MAT), which we developed, mast cells grown in the laboratory are brought into contact with blood serum from allergic patients. The mast cells bind the IgE antibodies from the serum and are sensitised by them. We can then stimulate the mast cells with different amounts of the allergens to be tested,” says Eggel. Quantifying the activated mast cells suggests how allergic a patient is to the allergen tested without needing to consume the food. 

Higher diagnostic accuracy than standard tests

The study used serum samples from a total of 112 children and adolescents who had already participated in a study in Canada and for whom clear diagnostic data on their peanut allergy status were available. The mast cells cultured in the laboratory were sensitised with their serum and then stimulated with peanut extract. “The cell-based test was easy to carry out and worked perfectly. All samples were measured within two days, which was very fast,” says Thomas Kaufmann. The results showed that a large number of sera from allergic patients exhibited allergen dose-dependent activation, while almost all samples from the non-allergic control subjects did not activate the mast cells. “An exceptionally high diagnostic accuracy of 95% could be calculated from these data,” Eggel adds.

In addition, the data measured in the study were analysed in direct comparison with other diagnostic methods established at the hospital. It was found that the Hoxb8 MAT test had significantly higher accuracy than the standard measurement of allergen-specific IgE antibodies in the blood or the frequently used skin test. “Comparison with other clinical tests was crucial to determine which of them reflected the patients’ allergic reaction best. The new mast cell activation test has the advantage that it is functional and therefore incorporates many parameters that are important for triggering the allergy,” says Thomas Kaufmann, adding: “The new test is also based on stable blood serum, which can be drawn using simple blood sampling and then stored in the freezer. This eliminates the challenging logistical obstacles that arise with other methods.” The study also showed that the Hoxb8 MAT test leads to less false negative results. 

“What has been shown in this study on the diagnosis of peanut allergies can also be applied to other allergies in a simple way. The technology is a perfect example of how basic research from the University of Bern can be brought to the clinical practice, and might ultimately simplify life for patients and physicians,” concludes Eggel.

Source: University of Bern

Categories : AllergiesTags :

Asthma Drug Omalizumab can Limit Allergic Reactions to Foods

On By ModernMedia
Photo by Camilo Jimenez on Unsplash

An existing biologic drug, omalizumab, can make life safer for children with food allergies by preventing dangerous allergic responses to small quantities of allergy-triggering foods, according to a new study led by scientists at the Stanford School of Medicine.

The findings, published in the New England Journal of Medicine, suggest that regular use of omalizumab could protect people from severe allergic responses, such as difficulty breathing, if they accidentally eat a small amount of a food they are allergic to.

“I’m excited that we have a promising new treatment for multifood allergic patients. This new approach showed really great responses for many of the foods that trigger their allergies,” said the study’s senior author, Sharon Chinthrajah, MD, associate professor of medicine and of pediatrics, and the acting director of the Sean N. Parker Center for Allergy and Asthma Research at Stanford Medicine.

“Patients impacted by food allergies face a daily threat of life-threatening reactions due to accidental exposures,” said the study’s lead author, Robert Wood, MD, professor of pediatrics at Johns Hopkins University School of Medicine. “The study showed that omalizumab can be a layer of protection against small, accidental exposures.”

Omalizumab, which the Food and Drug Administration originally approved to treat diseases such as allergic asthma and chronic hives, binds to and inactivates the antibodies that cause many kinds of allergic disease. Based on the data collected in the new study, the FDA approved omalizumab for reducing risk of allergic reactions to foods on Feb. 16.

All study participants were severely allergic to peanuts and at least two other foods. After four months of monthly or bimonthly omalizumab injections, two-thirds of the 118 participants receiving the drug safely ate small amounts of their allergy-triggering foods. Notably, 38.4% of the study participants were younger than 6 years, an age group at high risk from accidental ingestions of allergy-triggering foods.

Allergies are common

Food allergies affect about 8% of children and 10% of adults in the United States. People with severe allergies are advised to fully avoid foods containing their allergy triggers, but common allergens such as peanuts, milk, eggs and wheat can be hidden in so many places that everyday activities such as attending parties and eating in restaurants can be challenging.

“Food allergies have significant social and psychological impacts, including the threat of allergic reactions upon accidental exposures, some of which can be life-threatening,” Chinthrajah said. Families also face economic impacts from purchasing more expensive foods to avoid allergens, she added.

In the best available treatment for food allergies, called oral immunotherapy, patients ingest tiny, gradually increasing doses of allergy-triggering foods under a doctor’s supervision to build tolerance. But oral immunotherapy itself can trigger allergic responses, desensitization to allergens can take months or years, and the process is especially lengthy for people with several food allergies, as they are usually treated for one allergy at a time. Once they are desensitised to an allergen, patients also must continue to eat the food regularly to maintain their tolerance to it – but people often dislike foods they were long required to avoid.

“There is a real need for treatment that goes beyond vigilance and offers choices for our food allergic patients,” Chinthrajah said.

Omalizumab is an injected antibody that binds and deactivates all types of immunoglobin E, or IgE, the allergy-causing molecule in the blood and on the body’s immune cells. So far, omalizumab appears able to provide relief from multiple food allergens at once.

“We think it should have the same impact regardless of what food it is,” Chinthrajah said.

Injections stave off severe reactions

The study included 177 children with at least three food allergies each, of whom 38% were 1 to 5 years old, 37% were 6 to 11 years old, and 24% were 12 or older. Participants’ severe food allergies were verified by skin-prick testing and food challenges; they reacted to less than 100 milligrams of peanut protein and less than 300 milligrams of each other food.

Two-thirds of the participants were randomly assigned to receive omalizumab injections, and one-third received an injected placebo; the injections took place over 16 weeks. Medication doses were set based on each participant’s body weight and IgE levels, with injections given once every two or four weeks, depending on the dose needed. The participants were re-tested between weeks 16 and 20 to see how much of each allergy-triggering food they could safely tolerate.

Upon re-testing, 79 patients (66.9%) who had taken omalizumab could tolerate at least 600 mg of peanut protein, the amount in two or three peanuts, compared with only four patients (6.8%) who had the placebo. Similar proportions of patients showed improvement in their reactions to the other foods in the study.

About 80% of patients taking omalizumab were able to consume small amounts of at least one allergy-triggering food without inducing an allergenic reaction, 69% of patients could consume small amounts of two allergenic foods and 47% could eat small amounts of all three allergenic foods.

Omalizumab was safe and did not cause side effects, other than some instances of minor reactions at the site of injection. This study marks the first time its safety has been assessed in children as young as 1.

More questions

More research is needed to further understand how omalizumab could help people with food allergies, the researchers said.

“We have a lot of unanswered questions: How long do patients need to take this drug? Have we permanently changed the immune system? What factors predict which people will have the strongest response?” Chinthrajah said. “We don’t know yet.”

The team is planning studies to answer these questions and others, such as finding what type of monitoring would be needed to determine when a patient gains meaningful tolerance to an allergy-triggering food.

Many patients who have food allergies also experience other allergic conditions treated by omalizumab, Chinthrajah noted, such as asthma, allergic rhinitis (hay fever and allergies to environmental triggers such as mold, dogs or cats, or dust mites) or eczema. “One drug that could improve all of their allergic conditions is exactly what we’re hoping for,” she said.

The drug could be especially helpful for young children with severe food allergies, she added, because they tend to put things in their mouths and may not understand the dangers their allergies pose, she added.

The drug could also make it safer for community physicians to treat food allergy patients, since it cannot trigger dangerous allergic reactions, as oral immunotherapy sometimes does. “This is something that our food allergy community has been waiting a long time for,” Chinthrajah said. “It’s an easy drug regimen to implement in a medical practice, and many allergists are already using this for other allergic conditions.”

Source: Stanford Medicine

Categories : AllergiesTags :

Predicting and Preventing Anaphylaxis During Food Allergy Tests

On By ModernMedia
Photo by Corleto on Unsplash

A team of University of Michigan researchers developed a method that measures water loss from the skin to predict anaphylaxis during oral food challenges before it becomes clinically evident. The results are published in The Journal of Clinical Investigation.

Oral food challenges – when a patient ingests increasing doses up to a full serving of the suspected food allergen under supervision of a medical provider – are the diagnostic standard as skin and blood allergy tests have high false positive rates.

Although a highly accurate diagnostic test, patients often experience anaphylaxis during oral food challenges necessitating an epinephrine injection.

“This method could enhance the ability to detect and predict anaphylaxis during oral food challenges prior to the need for epinephrine, greatly improving patient safety and comfort,” said Charles Schuler, M.D., lead author of the study and an immunologist at Michigan Medicine.

Building on existing research

During anaphylaxis, the dilation or widening of the blood vessels increases heat and water loss from the surface of the skin.

Previous research has assessed facial thermography, which uses a specialized camera to detect heat patterns emitted from the skin, as a method to predict anaphylaxis.

However, this method requires optics expertise, tightly controlled conditions and for the patient to sit still for an extended period – making this an impractical choice, especially for assessing food allergies in children.

The researchers validated the use of transepidermal water loss, a measurement that represents the amount of water that escapes from a given skin area per hour, by comparing its ability to detect anaphylaxis with biochemical and clinical observation methods.

They found that transepidermal water loss increases during food allergy reactions and anaphylaxis.

The rise in skin water loss correlated with biochemical markers of anaphylaxis and substantially preceded clinical detection of anaphylaxis.

“Transepidermal water loss measurement can be done in office without specialized equipment, affixed to the skin and works in children making it a vast improvement from previous attempts at early anaphylaxis detection methods,” said Schuler.

Schuler’s research group is currently recruiting participants aged six months to five years old for a pilot clinical trial, Predicting Peanut Anaphylaxis and Reducing Epinephrine, that monitors transepidermal water loss from the forearm during a peanut allergy food challenge.

Results will help pinpoint values associated with anaphylaxis to determine “stopping rules” to end oral food challenges, hopefully reducing the need for epinephrine injections.

Source: Michigan Medicine – University of Michigan

Categories : Allergies GeneticsTags :

Can We Predict the Severity of Food Allergies Using Genetics?

On By ModernMedia
Photo by Sangharsh Lohakare on Unsplash

Researchers have discovered that a genetic biomarker may be able to help predict the severity of food allergy reactions. Currently there is no reliable or readily available clinical biomarker that accurately distinguishes patients with food allergies who are at risk for severe life-threatening reactions versus more mild symptoms. The researchers reported their findings in the Journal of Allergy and Clinical Immunology.

The researchers, led by Ann & Robert H. Lurie Children’s Hospital of Chicago, found that the presence of an enzyme isoform called α-tryptase, which is encoded by the TPSAB1 gene, correlates with increased prevalence of anaphylaxis or severe reaction to food as compared to subjects without any α-tryptase.

“Determining whether or not a patient with food allergies has α-tryptase can easily be done in clinical practice using a commercially available test to perform genetic sequencing from cheek swabs,” said lead author Abigail Lang, MD, MSc, attending physician and researcher at Lurie Children’s and Assistant Professor of Pediatrics at Northwestern University Feinberg School of Medicine. “If the biomarker is detected, this may help us understand that the child is at a higher risk for a severe reaction or anaphylaxis from their food allergy and should use their epinephrine auto-injector if exposed to the allergen. Our findings also open the door to developing an entirely new treatment strategy for food allergies that would target or block α-tryptase. This is an exciting first step and more research is needed.”

Tryptase is found mainly in mast cells, which become activated during allergic reactions. Increased TPSAB1 copy number which leads to increased α-tryptase is already known to be associated with severe reactions in adults with Hymenoptera venom allergy (or anaphylaxis following a bee sting).

Dr Lang’s study included 119 participants who underwent TPSAB1 genotyping, 82 from an observational food allergy cohort at the National Institute of Allergy and Infectious Diseases (NIAID) and 37 from a cohort of children who reacted to peanut oral food challenge at Lurie Children’s.

“We need to validate our preliminary findings in a much larger study, but these initial results are promising,” says Dr Lang. “We also still need a better understanding of why and how α-tryptase makes food allergy reactions more severe in order to pursue this avenue for potential treatment.”

Source: Ann & Robert H. Lurie Children’s Hospital of Chicago

Categories : Allergies PaediatricsTags :

Common Gut Microbiota Link to the Development of Childhood Allergies

On By ModernMedia
Photo by Andrea Piacquadio on Unsplash

Several major childhood allergies may all stem from the gut microbiome gut, according to a new study published in Nature Communications. The research identifies gut microbiome features and early life influences that are associated with children developing any of four common allergies. The study, led by researchers at the University of British Columbia and BC Children’s Hospital, could lead to methods of predicting whether a child will develop allergies, and methods to prevent their development.

“We’re seeing more and more children and families seeking help at the emergency department due to allergies,” said Dr Stuart Turvey, paediatrics professor at UBC and co-senior author on the study, noting that as many as one in three children in Canada have allergies.

The study is one of the first to examine four distinct school-aged paediatric allergies at once: atopic dermatitis, asthma, food allergy and allergic rhinitis. While these allergic diseases each have unique symptoms, the Turvey lab was curious whether they might have a common origin linked to the infant gut microbiota composition.

“These are technically different diagnoses, each with their own list of symptoms, so most researchers tend to study them individually,” says Dr Charisse Petersen, co-senior author on the paper and postdoctoral fellow in the Turvey lab. “But when you look at what is going wrong at a cellular level, they actually have a lot in common.”

For the study, researchers examined clinical assessments from 1115 children who were tracked from birth to age five. Roughly half of the children (523) had no evidence of allergies at any time, while more than half (592) were diagnosed with one or more allergic disorders by an expert physician. The researchers evaluated the children’s microbiomes from stool samples collected at clinical visits at three months and one year of age.

The stool samples revealed a bacterial signature that was associated with the children developing any of the four allergies by five years of age. The bacterial signature is a hallmark of dysbiosis, or an imbalanced gut microbiota, that likely resulted in a compromised intestinal lining and an elevated inflammatory response within the gut.

“Typically, our bodies tolerate the millions of bacteria living in our guts because they do so many good things for our health. Some of the ways we tolerate them are by keeping a strong barrier between them and our immune cells and by limiting inflammatory signals that would call those immune cells into action,” says Courtney Hoskinson, a PhD candidate at UBC and first author on the paper. “We found a common breakdown in these mechanisms in babies prior to the development of allergies.”

Many factors can shape the infant gut microbiota, including diet, place and delivery method of birth and antibiotics exposure. The researchers examined how these types of influences affected the balance of gut microbiota and the development of allergies.

“There are a lot of potential insights from this robust analysis,” says Dr Turvey. “From these data we can see that factors such as antibiotic usage in the first year of life are more likely to result in later allergic disorders, while breastfeeding for the first six months is protective. This was universal to all the allergic disorders we studied.”

Now the researchers hope to leverage the findings to inform treatments that correct an imbalanced gut microbiota and could potentially prevent allergies from developing.

“Developing therapies that change these interactions during infancy may therefore prevent the development of all sorts of allergic diseases in childhood, which often last a lifetime,” says Dr Turvey.

Source: University of British Columbia

Categories : Allergies PaediatricsTags :

Food Allergy in Infancy Linked to Childhood Asthma and Reduced Lung Function

On By ModernMedia
Photo by Corleto on Unsplash

Infants that have a food allergy have an increased risk of asthma and reduced lung function later in childhood, according to a world first study published in the Lancet Child & Adolescent Health.

Food allergy affects 10% of babies and 5% of children and adolescents. The research, led by Murdoch Children’s Research Institute, found that early life food allergy was associated with an increased risk of both asthma and reduced lung growth at six years of age.

Murdoch Children’s Associate Professor Rachel Peters said this was the first study to examine the relationship between challenge-confirmed food allergy in infancy and asthma and poorer lung health later in childhood.

The Melbourne research involved 5276 infants from the HealthNuts study, who underwent skin prick testing to common food allergens, such as peanut and egg, and oral food challenges. At six years, children were followed up with further food allergy and lung function tests.

The study found by six years of age, 13.7% reported a diagnosis of asthma. Babies with a food allergy were almost four times more likely to develop asthma at six years of age, compared to children without a food allergy. The impact was greatest in children whose food allergy persisted to age six as opposed to those who had outgrown their allergy. Children with a food allergy were also more likely to have reduced lung function.

Associate Professor Peters said food allergy in infancy, whether it resolved or not, was linked to poorer respiratory outcomes in children.

“This association is concerning given reduced lung growth in childhood is associated with health problems in adulthood including respiratory and heart conditions,” she said.

“Lung development is related to a child’s height and weight and children with a food allergy can be shorter and lighter compared to their peers without an allergy. This could explain the link between food allergy and lung function. There are also similar immune responses involved in the development of both food allergy and asthma.

“The growth of infants with food allergy should be monitored. We encourage children who are avoiding foods because of their allergy to be under the care of a dietician so that nutrition can be catered for to ensure healthy growth.”

Source: Murdoch Childrens Research Institute

Categories : Allergies PaediatricsTags :

IgA Antibodies Do not Prevent Childhood Food Allergies

On By ModernMedia
Photo by Corleto on Unsplash

The presence of food-specific IgA antibodies in the gut does not prevent peanut or egg allergies from developing in children, according to a Northwestern Medicine study published in Science Translational Medicine.

Scientists examined stool samples from more than 500 infants across the country and found that the presence of Immunoglobulin A, the most common antibody found in mucous membranes in the digestive tract, does not prevent peanut or egg allergies from developing later in life.

This discovery calls into question the role of Immunoglobulin A, or IgA, which was previously thought to be a protective factor against the development of food allergies.

Peanuts and eggs are the two most common allergens for infants and affect an estimated one in 13 children in the US, according to the Ann & Robert H. Lurie Children’s Hospital of Chicago.

While prior research had shown IgA could bind to and neutralide toxins and bacteria in the body, there was inconclusive evidence that IgA could do the same for food allergens, said Stephanie Eisenbarth, MD, PhD, senior author of the study.

“We were able to collaborate with different groups around the country to look at a number of different cohorts of children and young adults to ask: ‘Does the presence of IgA to peanut tell us that the person is tolerant to peanut?’,” said Eisenbarth. “We found that there really was no difference between kids who had peanut allergies and children who didn’t, and the same is true with egg allergies.”

The findings come as rates of allergies in children continue to climb: According to data from the Centers for Disease Control and Prevention, the number of children with allergies has more than doubled in the last 20 years.

Future directions for research will center on understanding the role IgA plays in people who have undergone immunotherapy and developed a tolerance to food allergens, Eisenbarth said.

Source: Northwestern University

Categories : AllergiesTags :

A New Guideline for Pollen Food Syndrome

On By ModernMedia
Photo by Daria Shevtsova on Pexels

Pollen Food Syndrome (PFS) – also known as oral allergy syndrome or pollen food allergy syndrome – causes affected individuals to experience an allergic reaction when consuming raw plant foods, and triggers can vary depending on an individual’s pollen sensitisation, which in turn is affected by geographical location. A guideline, published in Clinical & Experimental Allergy, has been developed for the diagnosis and management of PFS.

The guideline was drafted by the British Society of Allergy & Clinical Immunology Standards of Care Committee. The correct diagnosis of PFS ensures the avoidance of a misdiagnosis of a primary peanut or tree nut allergy or confusion with another plant food allergy to non-specific lipid transfer proteins. The characteristic foods involved, and rapid-onset oropharyngeal symptoms, mean PFS can often be diagnosed from the clinical history alone. Management focuses on avoiding known trigger foods, which may appear to be simple, but can be difficult if coupled with a pre-existing food allergy, or for individuals following a vegetarian/vegan diet.

“More studies on the effect of PFS on health-related quality of life are needed to dispel the myth that because it usually manifests with mild symptoms, PFS is easily managed, and does not adversely affect the individual,” the authors wrote. “The number of foods and concern about new food triggers means dietary restrictions are often overly strict, so more research on novel treatments of PFS, including food immunotherapy, needs to be undertaken.”

Source: Wiley