Egg Hypersensitivity

Allergic transfusion reactions (ATRs), a potentially life-threatening side effect of blood transfusions with unclear mechanisms, may be linked to food allergies in pediatric patients as per a recent study by scientists from Japan. They found that ATRs may be triggered by the presence of allergens in the donor's blood, influenced by their pre-donation diet. These findings could pave the way for safer blood transfusions through the development of preventive measures and countermeasures for ATRs. Allergic transfusion reactions (ATRs), a potentially life-threatening side effect of blood transfusions with unclear mechanisms, may be linked to food allergies in pediatric patients as per a recent study by scientists from Japan. They found that ATRs may be triggered by the presence of allergens in the donor's blood, influenced by their pre-donation diet. These findings could pave the way for safer blood transfusions through the development of preventive measures and countermeasures for ATRs. Blood transfusions are often life-saving procedures in various medical settings. They are required not only after severe blood loss due to surgery or trauma but also as standard treatment for certain blood disorders like anemia and sickle cell disease. However, blood transfusions can have serious side effects, with allergic transfusion reactions (ATRs) being particularly prevalent among children. Although scientists believe ATRs are caused by immunoglobulin E (IgE)-mediated type 1 allergy (or "immediate hypersensitivity"), the responsible allergens are not always known. Against this backdrop, a research team composed of Dr. Ryu Yanagisawa of Shinshu University Hospital, Japan, alongside Dr. Minoru Tozuka and Dr. Yasunori Ito from Nagano Children's Hospital, Japan, set out to find more answers. In their latest study, published online in the journal Allergy on January 11, 2024, the researchers focused their attention on what might have appeared to be an unlikely suspect. Dr. Yanagisawa, who led the study at the University's Division of Blood Transfusion, explains: "In our previous study, we found that pediatric patients with food allergies were characteristically more prone to ATRs. Considering that food allergies are also more prevalent in children, we decided to investigate whether the food the donor ate before giving blood could be associated with the development of ATRs in children with food allergies." Between May 2022 and December 2023, the researchers collected blood samples from over 100 pediatric patients with diagnosed food allergies toward either eggs, wheat, or milk. They also collected blood from two healthy donors before and after substantial ingestion of these food products and extracted the serum. Shortly after collecting blood from each allergic patient, the researchers conducted basophil activation tests (BATs) by exposing the sample to the corresponding sera. As the name implies, these tests assess the activation of basophils, a particular type of white blood cell that is strongly involved in allergic reactions. Interestingly, in patients with egg allergy, BAT levels were significantly higher when the blood was exposed to the serum of donors who had ingested eggs. Moreover, serum obtained from blood donor samples collected four hours after egg ingestion resulted in markedly higher BAT levels than those collected two hours after egg ingestion. In contrast, the results for milk and wheat were more varied, with BAT levels only being elevated after exposure to the serum of one of the two donors. To gain deeper insights and lend more weight to the results, the researchers decided to run BAT tests with sera from sixteen additional donors. "Although some differences were observed among donors, blood samples obtained after egg ingestion generally activated basophils in cases of egg allergy with high egg white-specific IgE levels," comments Dr. Yanagisawa. "Similarly, elevated BAT levels in patients with milk and wheat allergies were also associated with allergen-specific IgE levels." Overall, the evidence obtained through this study strongly suggests that ATRs could be triggered by the food consumed by donors prior to a blood donation. Although further analyses and experiments will be needed to confirm this with more certainty, these efforts constitute a necessary first step towards elucidating the mechanisms underlying ATRs. "In future, it could be possible to predict in advance who is likely to suffer from an ATR. Given enough time, preventive measures and countermeasures to ATRs could be developed, leading to safer blood transfusions," concludes Dr. Yanagisawa. It is hoped that this study puts scientists on the right path toward cracking the mysteries of ATRs to improve the outcome of blood transfusions.

WEDNESDAY, Aug. 2, 2023 -- Food allergy in infancy, whether it resolves or not, is associated with lung function deficits and asthma at age 6 years, according to a study published online July 25 in The Lancet Child & Adolescent Health . Rachel L. Peters, Ph.D., from Murdoch Children's Research Institute in Parkville, Australia, and colleagues used data from 5,276 children aged 1 year who attended immunization sessions (Sept. 28, 2007, to Aug. 5, 2011). At 1 year of age, all children completed skin prick testing for four food allergens (egg, peanut, sesame, and either shrimp or cow's milk) and an oral food challenge (egg, peanut, and sesame). The analysis included 3,233 who also completed the health assessment at age 6 years. The researchers found that food allergy, but not food-sensitized tolerance, at age 1 year was associated with reduced forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) at age 6 years. Transient egg allergy was associated with reduced FEV1 and FVC compared with never having egg allergy, but persistent egg allergy was not. Transient, persistent, and late-onset peanut allergy were associated with reduced FEV1 and FVC. Although some were imprecise, estimates suggested that food-sensitized tolerance and food allergy were associated with reduced forced expiratory flow at 25 percent and 75 percent of the pulmonary volume. There was no association between food allergy phenotypes and FEV1/FVC ratio. There was an association between both food-sensitized tolerance and food allergy at age 1 year with increased asthma risk at age 6 years. Asthma risk was even higher for persistent and late-onset peanut allergy. "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," Peters said in a statement. "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." Several authors disclosed financial ties to industry. Abstract/Full Text (subscription or payment may be required) Editorial (subscription or payment may be required) Posted August 2023

THURSDAY, July 13, 2023 – Development of egg allergy at 12 months is unaffected by maternal egg consumption during the very early neonatal period, according to a study published July 10 in JAMA Network Open . Ken-ichi Nagakura, M.D., Ph.D., from the National Hospital Organization Sagamihara National Hospital in Japan, and colleagues examined the effect of maternal egg intake during the early neonatal period on the development of egg allergy in breastfed infants at age 12 months. Analysis included 380 newborns randomly assigned (1:1) to a maternal egg consumption group (mothers consumed one whole egg per day during the first five days of the neonate’s life) or the maternal egg elimination group. The researchers found that on days 3 and 4 after delivery, the proportions of neonates with ovalbumin and ovomucoid detection in breast milk were higher in the egg consumption group versus the elimination group (ovalbumin: 10.7 versus 2.0 percent; risk ratio [RR], 5.23 [95 percent confidence interval (CI), 1.56 to 17.56]; ovomucoid: 11.3 versus 2.0 percent; RR, 5.55 [95 percent CI, 1.66 to 18.55]). The groups did not significantly differ at age 12 months for egg allergy (9.3 versus 7.6 percent; RR, 1.22; 95 percent CI, 0.62 to 2.40) or sensitization to egg white (62.8 versus 58.7 percent; RR, 1.07; 95 percent CI, 0.91 to 1.26). "It is possible that the ingestion of larger amounts of egg protein and a longer intervention period, such as during pregnancy or after the neonatal period, might lead to different results," the authors write. Abstract/Full Text Posted July 2023