Researchers have created a new test aimed at making allergy diagnoses easier. This test’s effectiveness has been validated using clinical samples from children and teens diagnosed with peanut allergies. The findings could significantly enhance how allergies are diagnosed in the future.
Food allergies represent a significant health issue globally, with some regions seeing up to 10% of their populations affected, primarily young children. Among these allergies, peanut allergy is notably prevalent and can trigger severe, life-threatening reactions. The emotional toll of food allergies extends beyond those directly affected, impacting families, the healthcare system, and the food industry as a whole. Currently, the oral food challenge test, which involves consuming the allergen (like peanut extract) under medical supervision to assess allergic reactions, remains the standard diagnostic tool. However, this method is complex and carries health risks. On the other hand, skin prick tests and blood tests often lack accuracy, which can lead to misdiagnoses and unnecessary food avoidance.
A research team led by Prof. Dr. Alexander Eggel from the Department for BioMedical Research (DBMR) at the University of Bern, along with Prof. Dr. Thomas Kaufmann from the Institute of Pharmacology at the same university, designed an alternative test in 2022. This new test simulates allergic reactions in a controlled laboratory setting, presenting a promising alternative to traditional methods. The Bern researchers have recently evaluated the test’s effectiveness on patients with confirmed peanut allergies and on a healthy control group, in a clinical study conducted in collaboration with the Hospital for Sick Kids in Toronto, Canada. Their findings illustrate that this new test boasts a higher diagnostic precision compared to existing methods. The study’s results have been published in the European Journal for Allergy and Clinical Immunology (Allergy).
Mast cell activation test as suitable alternative
“Type I allergies, the most common kind, occur when the body produces immunoglobulin E (IgE) antibodies against traditionally harmless substances (allergens),” explains Alexander Eggel. These antibodies attach themselves to specific receptors on mast cells, immune cells crucial for both allergic reactions and inflammation. Mast cells, predominantly found in tissues like the intestinal lining, become sensitized to allergens when they bind with these antibodies. Upon subsequent exposure to the allergen, it directly interacts with the sensitized mast cells, leading to their activation and an allergic response. “In the Hoxb8 mast cell activation test (Hoxb8 MAT), which we developed, laboratory-cultured mast cells are exposed to blood serum from allergic patients. The mast cells absorb IgE antibodies from the serum and become sensitized. Then, we can expose these mast cells to varying amounts of the test allergens,” Eggel explains. By measuring the quantity of activated mast cells, we can assess the patient’s level of allergy to the tested allergen without requiring them to ingest the food itself.
Greater diagnostic accuracy than standard tests
The research utilized serum samples from 112 children and adolescents who participated in a prior study in Canada, and for whom a clear peanut allergy diagnosis was established. The cultured mast cells were sensitized with their serum and subsequently exposed to peanut extract. “The cell-based test was straightforward to conduct and yielded excellent results. All samples were processed within two days, which was impressively quick,” remarks Thomas Kaufmann. The outcomes revealed that many serum samples from allergic individuals displayed a dose-dependent activation of allergens while nearly all samples from non-allergic control subjects did not activate the mast cells. “We achieved an exceptional diagnostic accuracy of 95% based on this data,” adds Eggel.
Furthermore, the results from this study were compared directly with other recognized diagnostic methods used at the hospital. The findings indicated that the Hoxb8 MAT test surpassed traditional IgE antibody blood tests and commonly used skin tests in terms of accuracy. “Evaluating the new test against other clinical tests was essential to determine which one best reflected patients’ allergic responses. The new mast cell activation test is advantageous as it is functional, incorporating several critical parameters related to allergy triggers,” says Thomas Kaufmann. He also mentions that “the new test relies on stable blood serum, which can be easily collected through standard blood sampling and stored in a freezer, mitigating the logistical challenges faced with other methods.” The study further demonstrated that the Hoxb8 MAT test resulted in fewer false-negative results.
“The insights gained from diagnosing peanut allergies can also be easily adapted to other types of allergies. This technology exemplifies how fundamental research conducted at the University of Bern can be translated into clinical practice, potentially simplifying life for both patients and healthcare providers,” concludes Eggel.
