Allergic reactions to emerging food allergens in Canadian children

A sensitive CRISPR/Cas12a-assisted fluorescent aptasensor for rapid detection of food allergens

Food allergens elicit abnormal immune system responses among allergic individuals and sensitive detection for allergenic ingredient is greatly significant. To address this need, a novel fluorescent aptasensor, assisted by Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR), have been developed for food allergens. In this study, aptamer offers distinctive recognition capabilities in binding specific targets, while CRISPR-associated-12a protein (Cas12a) holds precise cis-cleavage for cutting fluorescent signal probes. Notably, the utilization of Cas12a cis-cleavage activity, rather than trans-cleavage, eliminates the necessity for additional fluorescent probes, thus reducing interference between substances and enhancing sensitivity. Throughout the process, complementary DNA (cDNA) plays a crucial dual role in target recognition conversion and signal presentation, representing a key challenge and innovative aspect of this study. To evaluate the performance of the aptasensor, lysozyme (LYS) is employed as a representative model target of food allergens. Under optimal conditions, the developed aptasensor could achieve an exceptional low limit of detection (LOD) of 6.10 pM with a dynamic detection range of 10 pM-320 pM. The aptasensor demonstrates high selectivity and great recovery rates. This strategy yields promising outcomes, holding the potential to serve as a valuable reference for various food allergens detection.

"Vegan" and "plant-based" claims: risk implications for milk- and egg-allergic consumers in Canada

The market share of foods carrying labels suggesting absence of animal ingredients has significantly increased in recent years. The purpose of this study was to document the purchasing behaviour of egg- or milk-allergic consumers vis-à-vis food marketed as "vegan" and "plant-based", and to evaluate the associated allergenic risk. A survey was conducted among egg- and milk-allergic consumers and revealed that 86% (margin of error 5.4%; confidence level 95%) would buy "vegan" products, indicating this label may be perceived as a substitute for "free from milk and eggs". To assess the risk posed by these products, 87 prepackaged foods with "vegan" and/or "plant-based" claims purchased in Quebec were tested for milk proteins, and 64 for egg proteins. Overall, 5.7% and 0% occurrence of milk and egg proteins, respectively, were observed, suggesting that the analysed prepackaged foods carrying "vegan" and/or "plant-based" labels pose little risk to egg- or milk-allergic consumers. However, this is likely due to allergen management practices applied by the Canadian manufacturers of the products tested, and should not be attributed to the use of "vegan" or similar labels. Enhanced regulatory requirements for the use of these labels, and an education campaign on their meaning with respect to allergy-related risks, are necessary to better inform and protect egg- and milk-allergic consumers.

A practical focus on legume oral immunotherapy

Legumes other than peanut are an important source of protein and consist of a wide variety of species, such as soy, peas, chickpeas, lentils, and lupin. Due to their health benefits and the rising popularity of veganism, legume consumption has increased. Legume allergy, cross-sensitization, and cross-reactivity between different species have been reported in the literature and are increasingly recognized. Unlike peanut, oral immunotherapy (OIT) for nonpeanut legumes has not been well studied and published protocols are lacking. Future studies are needed to provide real-world data on the safety and effectiveness of nonpeanut legume OIT, and whether desensitization to one legume leads to desensitization to other legumes in patients with multiple legume allergy. Nevertheless, due to the abundance of clinical trial and real-world data for peanut OIT, it is reasonable to use protocols that substitute peanut protein with other legume protein when desensitizing individuals with nonpeanut legume allergy. Clinicians who are starting to offer legume OIT in their practices may consider starting with preschoolers, an age group for whom real-world data has shown the greatest safety and effectiveness.

Alternatives to Cow’s Milk-Based Infant Formulas in the Prevention and Management of Cow’s Milk Allergy

Cow’s milk-based infant formulas are the most common substitute to mother’s milk in infancy when breastfeeding is impossible or insufficient, as cow’s milk is a globally available source of mammalian proteins with high nutritional value. However, cow’s milk allergy (CMA) is the most prevalent type of food allergy among infants, affecting up to 3.8% of small children. Hypoallergenic infant formulas based on hydrolysed cow’s milk proteins are commercially available for the management of CMA. Yet, there is a growing demand for more options for infant feeding, both in general but especially for the prevention and management of CMA. Milk from other mammalian sources than the cow, such as goat, sheep, camel, donkey, and horse, has received some attention in the last decade due to the different protein composition profile and protein amino acid sequences, resulting in a potentially low cross-reactivity with cow’s milk proteins. Recently, proteins from plant sources, such as potato, lentil, chickpeas, quinoa, in addition to soy and rice, have gained increased interest due to their climate friendly and vegan status as well as potential lower allergenicity. In this review, we provide an overview of current and potential future infant formulas and their relevance in CMA prevention and management.