Thermal processing of peanut impacts detection by current analytical techniques.
Recalls of spice containing products due to undeclared peanut have highlighted the importance of analytical methods in these foods. We examined the performance of peanut detection methods in cumin and garlic, focusing on quantitative ELISA. Although suitable for qualitative detection, accurate quantitation proved difficult. Roasting of peanut contaminants influenced ELISA results, with raw peanut over-detected (3.9-fold) and roasted peanut under-detected (3.5-fold). Further investigation demonstrated the importance of protein targets for ELISA. The kit which gave the least variable results was based on detection of 2S albumin proteins. Additionally, we show that these proteins are more efficiently extracted from roasted peanut. We conclude that current methods are largely suitable for the qualitative detection of peanut in cumin and garlic. Quantitation relies on assumptions as to the state of thermal processing of peanut. We suggest that analytical method providers address robust detection by target selection, including identifying targets by MS.
Peanut allergy diagnosis: moving from basic to more elegant testing.
Peanut allergy (PNA) is an IgE-mediated immune disorder which merits particular attention due to its impact on the health and quality of life of millions of patients worldwide. PNA tends to develop in early life and resolves in only 20% of peanut-allergic children. It accounts for the majority of severe food-related allergic reactions. An accurate diagnosis of PNA is vital. In this review we present the approach to the diagnosis of peanut allergy, starting from the history and proceeding to measures of overall sensitization and then to component-resolved diagnostics and oral food challenges as indicated. Additional testing in development include basophil activation testing and determination of epitopes for peanut allergic responses. Based on the literature stepwise approaches and predictive models for diagnosing PNA are also presented.
Food Allergy Prevention: More Than Peanut.
Given an apparent increase in food allergies worldwide, the focus on prevention strategies has intensified. Following the Learning Early About Peanut study, there is now a widespread acceptance that peanut should be introduced promptly into the diet of high-risk infants. However, most food allergies are caused by triggers other than peanut and additional prevention strategies are being evaluated. The appreciation of the role of an impaired skin barrier in the process of food sensitization and subsequent allergy has led to a spectrum of dermatologically orientated studies. Other prevention strategies address the role of the microbiome, dietary components, and other modifiable risk factors. With regard to early introduction of foods other than peanut, studies are heterogeneous in design and governmental and professional society response to the early introduction trials has varied, ranging from new guidelines confining advice specifically to peanut, to ones recommending prompt introduction of a broad spectrum of allergenic foods. Much remains to be determined with regard to the acceptability and uptake of the new guidelines and their impact on infant feeding behavior and food allergy outcomes. This review discusses the panoply of prevention approaches, their promise, and limitations.
Food Allergy: A Review.
Food allergy is an important public health problem that affects children and adults, and it has been increasing in prevalence in the last 2 to 3 decades. The symptoms can vary from mild to severe, and in extreme cases food allergy can lead to anaphylaxis, which is a life-threatening allergic reaction. Currently, there is no cure for food allergy. Management of food allergy includes allergen avoidance or emergency treatment. The eight most common food allergens are eggs, milk, peanuts, tree nuts, soy, wheat, crustacean shellfish, and fish, all of which are frequently consumed in the US. Thus, patients and their families must remain constantly vigilant, which can often be stressful. Moreover, nonallergic food reactions, such as food intolerance, are commonly mistaken as food allergies. This article highlights risk factors, natural history, diagnosis, and management of food allergy.
Commercial Claims Costs Related to Healthcare Resource Use Associated With a Diagnosis of Peanut Allergy.
Background: Peanut allergy (PA) affects ∼1.6 million US children. The current standard of care is strict avoidance and prompt reaction treatment. PA healthcare costs and healthcare resource utilization (HCRU) are poorly understood. Objective: To estimate PA healthcare costs and HCRU using a nationally representative commercial payer database. Methods: The IBM MarketScan ® Commercial Claims and Encounters Database was examined for PA diagnosis/reaction codes between January 2011 and October 2015 in patients ≤64 years, with age cohort-matched controls. Outcomes were measured 12 months before and after the first claim date. Healthcare costs and HCRU were compared using Student's t-tests and chi-square tests. Results: Patients with a PA-related diagnostic code (n=41,675) incurred almost double all-cause healthcare costs versus controls ($6436 vs $3493, P <0.001), mainly from inpatient and outpatient medical costs ($5002 vs $2832, P <0.001). Over 1/3 of the PA group patients (36%) had a code indicative of an anaphylactic reaction during follow-up. Mean PA or reaction-related code costs per visit totaled $7921 for hospitalizations and $1115 for emergency department (ED) visits. Costs were 30% lower in patients with asthma codes without PA codes versus those with both codes ($5678 vs $8112, P <0.001); all-cause ED costs were more than double in patients with atopic dermatitis codes with PA codes versus those without PA codes ($654 vs $308, P <0.001). Conclusion: National commercial payer claims data indicate a significant healthcare burden associated with a PA-related code, including over $6400/patient in annual allcause costs and increased healthcare utilization.
Vaccine against peanut allergy based on engineered Virus-Like-Particles displaying single major peanut allergens.
Background: Peanut allergy is a severe and increasingly frequent disease with high medical, psychosocial and economical burden for affected patients. A causal, safe and effective therapy is not available. Objective: We aimed to develop an immunogenic, protective and non-reactogenic vaccine candidate against peanut allergy based on Virus-like Particles (VLPs) coupled to single peanut allergens. Methods: To generate vaccine candidates, extracts of roasted peanut (Ara R) or the single allergens Ara h 1 or Ara h 2 were coupled to immunologically optimized Cucumber Mosaic Virus-derived VLPs (CuMVtt). BALB/c mice were sensitized intraperitoneally with peanut extract absorbed to Alum. Immunotherapy consisted of one single subcutaneous injection of CuMVtt coupled to Ara R, Ara h 1 or Ara h 2. Results: The vaccines CuMVtt-Ara R, CuMVtt-Ara h 1 and CuMVtt-Ara h 2 protected peanut sensitized mice against anaphylaxis after i.v. challenge with the whole peanut extract. Vaccines did not cause allergic reactions in sensitized mice. CuMVtt-Ara h 1 was able to induce specific IgG antibodies, diminished local reactions after skin-prick-tests and reduced the infiltration of the gastrointestinal tract by eosinophils and mast cells after oral challenge with peanut. The ability of CuMVtt-Ara h 1 to protect against challenge with the whole extract was mediated by IgG, as shown via passive IgG transfer. FcγRIIb was required for protection, indicating that immune-complexes with single allergens were able to block the allergic response against the whole extract, consisting of a complex allergen mixture. Conclusion: Our data suggest that vaccination using single peanut allergens displayed on CuMVtt may represent a novel and safe therapy against peanut allergy.
Comparative analysis of eliciting capacity of raw and roasted peanuts: the role of gastrointestinal digestion.
This study investigated the simultaneous impact of food matrix and processing on the food allergy eliciting capacity of peanuts in a physiologically relevant context. Whole raw and roasted peanuts were subjected to in vitro digestion combining the harmonized oral-gastric-duodenal digestion models with brush border membrane enzymes (BBM) to simulate the jejunal degradation of peptides. SDS-PAGE and HPLC analysis showed that roasting increased digestibility of peanuts and this trend was even more evident after BBM degradation. The eliciting properties of raw and roasted peanuts were assessed by Rat Basophil Leukemia assay in the presence of sera from peanut-allergic patients. As general features, the BBM digestion reduced allergenicity of roasted peanuts compared to the raw counterpart, suggesting that intestinal peptidases effectively contribute to further destroy specific domains of peanut allergens. These findings provide new and more realistic insights in the stability of peanut allergens within their natural matrix.
Advances in the management of peanut allergy (oral immunotherapy and epicutaneous immunotherapy).
Background: Peanut allergy affects up to 2% of the general population and carries not only the risk of potentially life-threatening allergic reactions but also negatively impacts day to day life for patients and their families. Advances in knowledge in immunotherapy is providing families with options for proactive treatment. Objective: To examine the available data for oral immunotherapy (OIT) and epicutaneous immunotherapy (EPIT) for peanut allergy. Methods: This review discusses recent studies that evaluated the safety and efficacy of OIT and EPIT to induce desensitization to peanut and identifies factors that should be considered when guiding families in treatment decisions. Results: Results of studies have demonstrated that immunotherapy can raise the threshold of peanut allergen to induce allergic reactions for many patients, thereby potentially reducing the risk for allergic reactions and decreasing the daily burden of peanut allergy. However, adverse reactions, which range from mild to severe, are possible with immunotherapy. Shared decision-making will be important to determine the best approach for peanut allergy management for each individual and his or her family. Conclusion: OIT and EPIT will offer patients and families more options for managing peanut allergies. Recent data from phase III studies on OIT and EPIT as well as real-world data on OIT advance the understanding of the efficacy and safety of these approaches. On-going studies aim to identify biomarkers to enhance patient selection criteria as well as develop additional therapeutic approaches.
Real-world tree nut consumption in peanut-allergic individuals.
Background: Individuals with peanut allergy often avoid tree nuts, yet true rates of tree nut allergy in peanut-allergic individuals are as low as 7%. Objective: To examine tree nut sensitization patterns in peanut-allergic individuals, patient and family choice regarding tree nut consumption, and factors that influence consumption of tree nuts. Methods: All patients presenting for peanut allergy evaluation to an outpatient allergy office were included during a 4-month period. In addition to demographic information, sensitization to tree nuts and tree nut consumption were collected. Logistic regression was performed to generate odds ratios with 95% CIs in univariate and multivariate analyses for variables that predict tree nut consumption. Results: A total of 258 individuals with peanut allergy were enrolled. Ninety-five (36.8%) consumed all tree nuts ad libitum, 63 (24.4%) consumed some but not all tree nuts, and 100 (38.8%) consumed no tree nuts. Of the 100 electively avoiding all tree nuts, the most commonly reported reason was fear of cross-contact (50%). Although there was no difference between rates of sensitization between individual tree nuts (P = .056), cashew and pistachio had higher serum specific IgE levels compared with other tree nuts (P < .001). The tree nut most commonly consumed by peanut-allergic individuals was almond (P < .001). Consumption of foods with precautionary labeling was the strongest predictor of tree nut consumption in peanut allergic individuals (P < .001) CONCLUSION: Our data highlight the potential for safe introduction of tree nuts in peanut-allergic individuals and indicate that peanut-allergic individuals who consume foods with precautionary labeling are most likely to consume tree nuts.
Defining challenge-proven coexistent nut and sesame seed allergy: A prospective multicenter European study.
Background: Peanut, tree nut, and sesame allergies are responsible for most life-threatening food-induced allergic reactions. Rates of coexistent allergy between these foods have been from mostly retrospective studies that include only a limited number of tree nuts or were not based on oral food challenges. Objective: The Pronuts study is a multicenter European study (London, Geneva, and Valencia) assessing the challenge-proven rate of coexistent peanut, tree nut, and/or sesame seed allergy. Methods: Children aged 0 to 16 years with at least 1 confirmed nut or sesame seed allergy underwent sequential diagnostic food challenges to all other nuts and sesame seed. Results: Overall, the rate of coexistent peanut, tree nut, and sesame seed allergy was 60.7% (n = 74/122; 95% CI, 51.4% to 69.4%). Peanut allergy was more common in London, cashew and pistachio nut allergies were more common in Geneva, and walnut and pecan allergies were more common in Valencia. Strong correlations were found between cashew-pistachio, walnut-pecan, and walnut-pecan-hazelnut-macadamia clusters. Age (>36 months) and center (Valencia > Geneva > London) were associated with an increased odds of multiple nut allergies. By pursuing the diagnostic protocol to demonstrate tolerance to other nuts, participants were able to introduce a median of 9 nuts. Conclusion: We found a higher rate of coexistent nut and sesame seed allergies than previously reported. Performing sequential food challenges was labor intensive and could result in severe allergic reactions; however, it reduced dietary restrictions. Age was a significant predictor of multiple nut allergies, and thus the secondary spread of nut allergies occurred in older children.