European annals of allergy and clinical immunology •
Epithelial barriers are crucial defenses against pathogens and allergens, and recent theories suggest that environmental factors may compromise them, leading to type 2 inflammation and conditions such as asthma, atopic dermatitis, food allergy, and rhinitis. While skin and respiratory barriers show clear dysfunctions in allergies, the role of the gut epithelium is less defined, particularly in view of its ability to absorb nutrients and maintain immune tolerance under normal conditions. Research indicates that gastrointestinal barrier integrity typically remains preserved in food allergies, allowing for the development of immune tolerance to ingested food antigens through mechanisms like Treg cells and IgA. Allergies to cow's milk or hen's egg proteins most often resolve with age, highlighting the gut's evolving role in allergen sensitization. Studies like the LEAP (Learning Early About Peanut Allergy) trial demonstrate the preventive benefits of early allergen exposure against peanut allergy, supporting the dual allergen exposure hypothesis. New allergens such as alpha-Gal and gibberellin-regulated proteins (GRP) reveal distinct sensitization pathways beyond traditional ingestion routes, implicating non-dietary sources in allergen introduction. Altogether, there is lack of evidence suggesting that the intestinal epithelium is disrupted in food allergy.
Villalta D, Cecchi L, Farsi A, Chiarini F, Minale P, et al.
European annals of allergy and clinical immunology •
The term of α-Gal syndrome, which includes the delayed allergy to red meat and the allergic reactions following the administration of cetuximab, is associated to the presence of specific IgE to α-Gal. In Italy, only anecdotal cases were reported so far. The Association of Italian Allergists (AAITO) carried out a survey with the aim of evaluating presence, characteristics, clinical features, and distribution of the syndrome in Italy. A web structured questionnaire was made available on the website of AAIITO from July 2016 to January 2017. It included 31 multiple-choice questions concerning different items, including the site of physicians, the number of patients diagnosed as having cetuximab allergy and/or delayed red meat allergy, recall of tick bites, symptoms, time to reactions, elicitor foods, reactions with foods other than meat, and in-vivo and in-vitro tests used for the diagnosis. Seventy-nine physicians completed the questionnaire. Nine cases of allergy to cetuximab and 40 cases of delayed red meat allergy were recorded across Italy. 22.5% of patients with cetuximab allergy and 62.5% of those with delayed red meat allergy recalled a tick bite. 75% of patients with delayed red meat allergy experienced symptoms after eating beef (butcher's cut in 72.5%). Urticaria was the most frequent clinical manifestation (65% of cases). In 60.6% of cases symptoms appeared 2 - 4 hours after meat ingestion, while in 7.9% symptoms appeared after > 4 hours. The most used diagnostic methods were the intradermal test for cetuximab allergy (88.9%) and the detection of IgE to α-Gal (55.5%) for red meat allergy. Most case reports came from Northern Italy. α-Gal syndrome is present in Italy and beef is the most frequent offending food. In most cases symptoms were not severe.