Epicutaneous peanut patch device for the treatment of peanut allergy.
Food allergy prevalence has increased in recent decades, which has mobilized efforts to develop treatment alternatives. Epicutaneous immunotherapy (EPIT) is a novel method that involves transdermal administration of peanut allergen with the objective to induce tolerance. Recent clinical trials have shown its efficacy at increasing the eliciting dose in children with a favorable safety profile. Areas covered: This review covers the proposed mechanism of action of EPIT in murine models and humans, efficacy and safety data from clinical trials with peanut EPIT, and a discussion on its potential role in the future management of peanut allergy. Expert opinion: With the recent completion of pivotal trials for peanut EPIT and upcoming marketing, the main question for clinicians and food allergic patients is how to define its role in the management of peanut allergy and how it compares to oral immunotherapy (OIT). Like OIT, EPIT seems to promote immunological tolerance over time. However, EPIT could lack the rapid mast-cell desensitization induced by the progressive intake of food in OIT, which explains differences in short-term outcomes and safety profiles. Head-to-head and long-term comparison of real-life efficacy with regards to sustained unresponsiveness will help define its place in the food allergy arsenal.
Evidence for a Role of TGF-β-Activated Kinase 1 and MAP3K7 Binding Protein 3 in Peanut-Specific T-Cell Responses.
Peanut allergy is considered to be the most common cause for food-induced anaphylaxis. Currently, no approved treatment is available. Avoidance is the only measure to prevent anaphylactic reactions to peanuts. T-helper cells are of special importance for the sensitization process and the maintenance of allergic inflammation. Identifying markers of allergen-specific T-cell responses may help to develop novel treatment approaches. Therefore, we aimed to define new T-cell target genes in Ara h 2-specific T cells and to investigate the possibility of using them as biomarkers of peanut allergy in peripheral blood mononuclear cells (PBMCs). We performed whole mRNA array analysis (whole human genome oligo microarray) of in vitro expanded Ara h 2-specific T cells (CFSElowCD3+CD4+) from 5 peanut-allergic (PA) and 5 non-peanut-sensitized individuals. Expression of selected genes as a result of a two-step bioinformatic approach was confirmed in a second cohort by quantitative PCR. TGF-β- activated kinase 1 and MAP3K7 binding protein 3 (TAB3), calcium/calmodulin-dependent protein kinase type IV (CAMK4) and HemK methyltransferase family member 1 (HEMK1) were significantly upregulated in Ara h 2-specific T cells of PA patients. In addition, the expression of these genes was also assessed in unstimulated PBMCs from a cohort (n = 43) of PA, atopic non-PA, and nonatopic controls. Interestingly, in unstimulated PBMCs, TAB3 expression was significantly downregulated in PA patients compared to atopic non-PA individuals. Thus, TAB3 may play a significant role at the level of T-cell activation and may also be a candidate biomarker for PA.
Microbial Adjuncts for Food Allergen Immunotherapy.
PURPOSE OF REVIEW: Food allergen immunotherapy may benefit from adjunct therapies to enhance safety and efficacy. We review preclinical studies investigating the effects of probiotics and other microbial-based interventions on oral tolerance, describe the human clinical trial evidence thus far for microbial adjuncts, and discuss steps for translating research findings in this area to clinical therapy. RECENT FINDINGS: Murine studies support that microbial-based interventions confer protection against sensitization and may augment treatment efficacy for food allergy. Microbial adjunct therapies can promote regulatory T cells and modulate Th1 vs. Th2 responses. There is a wide array of novel modalities utilizing microbial components. Ongoing efforts are focused on translating preclinical data into potential treatments. Probiotics, prebiotics, and microbial components have all been examined as microbial adjunct therapies in murine models of food allergy. The effects of probiotics appear to be strain-specific. Prebiotics and bacterial components are innovative modalities to modulate oral tolerance. Better characterization of dysbiosis in human cohorts with food allergy, deeper mechanistic understanding of microbial adjunct therapies, safety evaluation, and careful clinical trial design will be crucial for the development of microbial adjuncts for food allergen immunotherapy. Microbial adjunct therapies have the potential to enhance the efficacy, safety, and durability of food allergen immunotherapy.
Investigation of reduced ELISA recovery of almond and hazelnut traces from roasted nut samples by SDS-PAGE and mass spectrometry.
Western society is facing an increase in the number of food-allergic individuals, with rising incidence in the past years. Therefore, allergen-free food and accurate and reliable analysis of allergen contamination are essential for the protection of consumers. Yet, there is limited understanding on the effect of food processing on allergenicity and on the ability of available methods to detect trace contamination in processed food. Available studies addressing this have relied on sample processing on a laboratory scale. In this study, industry-like processing under precisely defined conditions (ranging from 110 to 150°C roasting temperatures) was employed to better understand the limitations of state-of-the-art methods for detecting traces of hazelnut and almond in processed food. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis indicated an overall reduction in extracted proteins from roasted nut samples, and with matrix-assisted laser desorption ionization time-of-flight Cor a 9 and Prunin, were identified as majorly expressed proteins for hazelnut and almond, respectively. A commercial ELISA kit detected nut traces only up to a 130°C roasting temperature. Untargeted MS (Orbitrap) analysis was able to detect traces of nuts roasted up to 150°C while also confirming Cor a 9 and Prunin as the major expressed proteins for hazelnut and almond, respectively. Preparing cookie dough spiked with roasted nut samples, a complex food matrix was simulated. Analysis by ELISA showed the same limitations encountered for pure nuts samples, hardly detecting traces of nuts roasted above 130°C. Targeted MS (linear ion trap) using multiple reaction monitoring methods for one proteotypic peptide for Cor a 9 and Prunin, respectively, enabled a detection of nut traces up to 150°C. The results indicated that a reduced extractability because of temperature-related effects (e.g., protein denaturation, cross-linking, poor solubility) caused the significant differences between the ELISA and MS analysis. Overall, the results of this study may form the basis to improve allergen detection after roasting through improved extraction methods and refined ELISA formats.
Walnut oral immunotherapy for desensitisation of walnut and additional tree nut allergies (Nut CRACKER): a single-centre, prospective cohort study.
BACKGROUND: The safety and efficacy of oral immunotherapy for tree nut allergy has not been demonstrated to date, and its effectiveness is complicated by the high prevalence of co-allergies to several nuts. This study aimed to investigate the use of walnut oral immunotherapy in the desensitisation of walnut and additional tree nuts in patients who are co-allergic to several nuts. METHODS: In a single-centre, prospective cohort study (the Nut Co-Reactivity ACquiring Knowledge for Elimination Recommendations study) at the Institute of Allergy, Immunology, and Paediatric Pulmonology at the Yitzhak Shamir Medical Centre, we recruited patients aged 4 years or older who were allergic to walnut, with or without co-allergy to pecan, hazelnut, and cashew. The diagnosis of each food allergy was based on a positive skin prick test or specific serum IgE (≥0·35 kUA/L) to the corresponding nut together with a positive oral food challenge, unless an immediate (within 2 h of exposure) reaction in the past year had been documented. Patients with uncontrolled asthma or a medical contraindication to receive adrenaline were excluded. Patients were assigned to walnut oral immunotherapy or the control group (observation and strict dietary exclusion) on the basis of the order of presentation to the clinic. Oral immunotherapy began with a 4-day dose-escalation phase to establish the single highest tolerated dose, which was consumed daily at home for 24 days; subsequent monthly dose escalations were repeated until 4000 mg walnut protein was achieved. Patients who were desensitised to walnut continued to consume 1200 mg walnut protein daily for 6 months as maintenance. The primary outcome was walnut desensitisation (passing an oral food challenge with 4000 mg of walnut protein) at the end of the study, analysed by intention to treat. In patients who were co-allergic to pecan, hazelnut, and cashew, the proportion who achieved cross-desensitisation to these nuts in addition to walnut desensitisation was examined. FINDINGS: 73 patients with a walnut allergy were enrolled between May 15, 2016, and Jan 14, 2018. 49 (89%) of 55 patients in the oral immunotherapy group were desensitised to walnut compared with none of 18 patients in the control group (odds ratio 9·2, 95% CI 4·3-19·5; p<0·0001). Following walnut desensitisation, all patients who were co-allergic to pecan (n=46) were also desensitised to pecan. Additionally, 18 (60%) of 30 patients who were co-allergic to hazelnut or cashew, and 14 (93%) of 15 patients who were co-allergic to hazelnut alone, were either fully desensitised or responded to treatment. 47 (85%) of 55 patients had an adverse reaction (mostly grade 1 or 2) during up-dosing in the clinic; eight patients required intramuscular epinephrine in response to a dose at home. Of 45 patients who had follow-up data for the maintenance phase, all maintained walnut desensitisation and one patient required epinephrine during this period. INTERPRETATION: Walnut oral immunotherapy can induce desensitisation to walnut as well as cross-desensitisation to pecan and hazelnut in patients who have tree nut co-allergies, with a reasonable safety profile. A low daily dose of the allergen maintains desensitisation.
Lipophilic allergens, different modes of allergen-lipid interaction and their impact on asthma and allergy.
Molecular allergology research has provided valuable information on the structure and function of single allergenic molecules. There are several allergens in food and inhalant allergen sources that are able to interact with lipid ligands via different structural features: hydrophobic pockets, hydrophobic cavities, or specialized domains. For only a few of these allergens information on their associated ligands is already available. Several of the allergens are clinically relevant, so that it is highly probable that the individual structural features with which they interact with lipids have a direct effect on their allergenic potential, and thus on allergy development. There is some evidence for a protective effect of lipids delaying the enzymatic digestion of the peanut (Arachis hypogaea) allergen Ara h 8 (hydrophobic pocket), probably allowing this molecule to get to the intestinal immune system intact (sensitization). Oleosins from different food allergen sources are part of lipid storage organelles and potential marker allergens for the severity of the allergic reaction. House dust mite (HDM), is more often associated with allergic asthma than other sources of inhalant allergens. In particular, lipid-associated allergens from Dermatophagoides pteronyssinuswhich are Der p 2, Der p 5, Der p 7, Der p 13, Der p 14, and Der p 21 have been reported to be associated with severe allergic reactions and respiratory symptoms such as asthma. The exact mechanism of interaction of these allergens with lipids still has to be elucidated. Apart from single allergens glycolipids have been shown to directly induce allergic inflammation. Several-in parts conflicting-data exist on the lipid (and allergen) and toll-like receptor interactions. For only few single allergens mechanistic studies were performed on their interaction with the air-liquid interface of the lungs, in particular with the surfactant components SP-A and SP-D. The increasing knowledge on protein-lipid-interaction for lipophilic and hydrophobic food and inhalant allergens on the basis of their particular structure, of their capacity to be integral part of membranes (like the oleosins), and their ability to interact with membranes, surfactant components, and transport lipids (like the lipid transfer proteins) are essential to eventually clarify allergy and asthma development.
Communicating the Protein Content of Plant-based Foods. Opportunities and Challenges
Amino acids are the building blocks for proteins; they are strung together in various combinations and lengths, according to instructions in our genetic material, to form all sorts of proteins, including hair, skin, nails, hormones, enzymes, and body structures such as muscle and bone. While the human body is capable of making some amino acids, 9 amino acids (i.e., histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine) cannot be made by the human body and are therefore considered essential. These 9 essential amino acids must be consumed from the diet to allow for the normal synthesis of proteins in the body.
Dietary proteins can be consumed either from animal or plant sources. Animal sources of protein include fish, poultry, meat, dairy products, and eggs. Plant sources of protein include legumes, nuts, seeds, grains, soy products, and some vegetables. While there are lots of terms to describe diets that are predominantly plant-based (Table 1), growing in popularity is the flexitarian diet (also referred to as the semi- or demi-vegetarian diet), a diet that is primarily vegetarian with the occasional inclusion of poultry, dairy, meat, fish, and eggs1. This dietary pattern is aligned with the recent recommendations of national scientific authoritative bodies with interests in public health. For example, a “Key Recommendation” of the U.S. Dietary Guidelines Advisory Committee -in their 2015-2020 Dietary Guidelines for Americans- is that a healthy eating pattern includes “a variety of protein foods, including seafood, lean meats and poultry, eggs, legumes (beans and peas), and nuts, seeds, and soy products”2. In Canada, as part of the “Let’s Eat Healthy Canada” initiative, Canadians are encouraged to eat vegetables and fruit, whole grains, and plant-based proteins to reduce the risks of heart disease, type 2 diabetes, and colorectal cancer3. To achieve these dietary recommendations, it is important for consumers to be able to identify plant-based foods that are good sources of protein. Unfortunately, in both the U.S. and Canada, the regulations make it very difficult for food manufacturers and distributors to label most plant-based foods as sources of protein. To understand the dilemma, it helps to first understand the regulations for labeling foods as sources of protein in other key markets, such as the European Union, Australia/New Zealand, and South Korea, and compare these to regulations in the US and Canada, using a mixture of nuts as an example.
Protein Level in Nut Mixture: According to the United States Department of Agriculture National Nutrient Database for Standard Reference Release 28, mixed nuts (dry roasted, with peanuts) contain 19.5 g of protein and 607 kcal per 100 g4; therefore, 12.9% of the energy in the mixed nuts is provided by protein.
Protein Claim Requirements in Europe: In Europe, a “source of protein claim” can be made if at least 12% of the energy value of a food is from protein5. Given that 12.9% of the energy value of the mixed nuts is from protein, the mixture of nuts can be labeled and advertised as a “source of protein”.
Protein Claim Requirements in Australia/New Zealand: In Australia/New Zealand, a “good source of protein” claim can be made if there are at least 5 g of protein per serving6. Given that each 30-gram serving of mixed nuts provides 5.9 g of protein, the mixture of nuts can be labeled and advertised as a “good source of protein”.
Protein Requirements in South Korea: In South Korea, a “source of protein” claim can be made if the food provides at least 10% of the protein Nutrient Reference Value (NRV) (i.e., 55 g) per 100 g, 5% of the protein NRV per 100 kcal, or 10% of the protein NRV per serving7. Given that the nut mixture provides 35.5% of the protein NRV per 100 g, 5.8% of the protein NRV per 100 kcal, and 10.6% of the protein NRV per 30-gram serving, the mixture of nuts can be labeled and advertised as a “source of protein”.
Clearly, in the European Union, Australia/New Zealand, and South Korea, the eligibility of a food for a protein content claim depends only on the amount of protein in the food. In the US and Canada, the eligibility of a food for a protein content claim is far more complex and depends not only on the amount of protein in the food, but also on the quality of the protein, measured as the “protein digestibility corrected amino acid score” in the US8 and as the “protein efficiency ratio” in Canada9. In both the US and Canada, the measure of protein quality depends on 2 factors:
- Whether all 9 essential amino acids are present in the protein; and,
- Whether the levels of essential amino acids are sufficient to support the growth of pre-school aged children (in the US) or young rats relative to casein (in Canada), after considering their digestibility (i.e., how well they are absorbed from the digestive tract after ingestion).
There are some circumstances where the protein quality of a food needs to be considered. For example, if the food is a staple for a given population (e.g., rice could be the main source of protein in a developing country), it is important to consider its quality, so that strategies to deliver all essential amino acids in the proper amounts could be generated. Likewise, the consideration of protein quality is very important if the population relies on formulated meal replacements or, in the case of infants, human milk substitutes like infant formula (i.e., the entire diet or a significant portion of it contains a single source of protein). For all other individuals who are generally healthy and have access to a variety of foods, amino acids that are absent or present at low levels in one food can be compensated for by higher levels in another food (Figure 1). For example, peanut butter and whole wheat bread individually do not have a high protein quality, but consumed together (e.g., a peanut butter sandwich), they provide a higher quality protein. Similarly, beans and rice individually do not have a high protein quality, but consumed together, they provide a higher quality protein. So, as long as all 9 essential amino acids are consumed, and as long as they are consumed in sufficient quantities, it does not matter whether they are all derived from a single, high quality protein food, or in multiple foods that, collectively, counterbalance each other with regards to protein quality.
Plant-based diets are known to improve health and reduce the risk of all-cause mortality and several cardiometabolic diseases, including, obesity, type 2 diabetes, and coronary heart disease1,10,11. Moreover, it is well-known that plant-based diets (rich in fruits, vegetables, legumes, seeds, nuts, and whole grains) have the least environmental impact in terms of their carbon footprints and are more sustainable than animal-based diets12,13,14. Thus, to encourage the consumption of plant-based foods, as per dietary guidelines and recommendations, perhaps it is time to modernize the regulations related to protein content claims in the US and Canada, and exercise more discretion in terms of when the protein quality of an individual food needs to be considered15.
References:
Derbyshire EJ. Flexitarian diets and health: a review of the evidence-based literature. Front Nutr. 2017;3:55 [8pp]. doi:10.3389/fnut.2016.00055. 2. Departments of Health and Human Services (DHHS) & Agriculture (USDA). 2015-2020 Dietary Guidelines for Americans. 8th ed., Washington, DC: 2015. 3. Health Canada. Let’s Eat Healthy Canada. Cat.: H164-209/2017E-PDF; Pub.: 170102. Health Canada, Ottawa, ON: 2017. 4. U.S. Department of Agriculture (USDA). Basic Report: 12135, Nuts, mixed nuts, dry roasted, with peanuts, without salt added. In: USDA National Nutrient Database for Standard Reference, Release 28, slightly revised. Software v.3.8.6.1, 2017-07-28). Agricultural Research Service (ARS), Nutrient Data Laboratory, Beltsville, MD: 2017. 5. European Parliament and the Council of the European Union. Regulation (EC) No 1924/2006 of the European Parliament and of the Council of 20 December 2006 on nutrition and health claims made on foods [L404]. Off J Eur Union 2006;49:9-25. 6. Foods Standards Australia New Zealand (FSANZ). Schedule 4 - Nutrition, health and related claims (F2017C00711). In: Australia New Zealand Food Standard Code. (Food Standards Australia New Zealand). (Federal Register of Legislation). Canberra, Australia / Wellington, NZ: 2017. 7. Ministry of Food and Drug Safety (MFDS). [Labeling Standards for Foods]. Chungcheongbuk-do, South Korea: 2014. 8. U.S. Food and Drug Administration (FDA). Part 101-Food labeling. §101.9-Nutrition labeling of food. In: U.S. Code of Federal Regulations (CFR). Title 21: Food and Drugs. U.S. Government Printing Office (GPO), Washington, DC: 2017. 9. Canadian Food Inspection Agency (CFIA). Specific nutrient content claim requirements. Protein claims. In: Food Labelling for Industry. (Industry Labelling Tool)., Ottawa, ON: 2016. (Date modified: 2016-08-23). 10. Tai Le L, Sabaté J. Beyond meatless, the health effects of vegan diets: findings from the Adventist cohorts. Nutrients. 2014;6:2131-47. 11. Kahleova H, Levin S, Barnard N. Cardio-metabolic benefits of plant-based diets. Nutrients 2017;9:848 [13pp]. doi:10.3390/nu9080848. 12. Barrett B, Grabow M, Middlecamp C, Mooney M, Checovich MM, Converse AK, Gillespie B, Yates J. Mindful climate action: health and environmental co-benefits from mindfulness-based behavioral training. Sustainability. 2016;8:pii:1040 [25pp]. doi: 10.3390/su8101040. 13. Gephart JA, Davis KF, Emery KA, Leach AM, Galloway JN, Pace ML. The environmental cost of subsistence: Optimizing diets to minimize footprints. Sci Total Environ 2016;553:120‑7. 14. Nelson ME, Hamm MW, Hu FB, Abrams SA, Griffin TS. Alignment of healthy dietary patterns and environmental sustainability: a systematic review. Adv Nutr 2016;7:1005-25. 15. Marinangeli CFP, Foisy S, Shoveller AK, Porter C, Musa-Veloso K, Sievenpiper JL, Jenkins DJ. An appetite for modernizing the regulatory framework for protein content claims in Canada. Nutrients 2017;9:921 [19]. doi:10.3390/nu9090921.
"Would I Recommend Eating Nuts to Increase Fertility? I Would Say: Why Not?"
First of all, could you explain what is the background behind the study?
Infertility is estimated to affect about 15% of all reproductive-age couples and 40-50% of cases are due to the male. Potential causes of infertility are associated with lifestyle, which includes dietary habits. Moreover, sperm quality may be modulated by inflammatory and oxidative processes, among others, thus compromising fertility. Since nuts modulate some of these molecular processes, we thought they should play a role in sperm quality.
Which was the starting point of this project?
In many fertility clinics antioxidant or other dietary supplements are recommended in order to improve fertility. However, the scientific evidence for these recommendations is very low. Some observational studies and randomized controlled trials have found that the adherence to a healthy diet, rich in omega-3, some antioxidants such as vitamin C and E, selenium and zinc, carnitines and folate, may improve semen quality and fecundability in men. Given that nuts are particularly rich in some of these nutrients, their consumption should beneficially affect semen quality.
What was the aim of the study?
The aim of the study was to demonstrate a beneficial role of regular consumption of nuts on classic and novel sperm quality parameters, which could be linked to an improvement in male fertility. The classic parameters include semen volume, total sperm count and concentration, vitality, motility and morphology, and are commonly used for clinical diagnoses. However, our study wanted to go further and so we looked in detail at potentially new markers at molecular levels including sperm DNA fragmentation, reactive oxygen species, micro RNAs, DNA methylation and chromosomal anomalies. These parameters are beyond those commonly assessed but we suspected that they would be closely related.
119 young men participated in the research. Can you give us a description of the study? This was a randomized controlled study conducted on 119 healthy males who follow a western-style diet, which is vastly different from a Mediterranean one. Participants were assigned to either a group that followed their usual diet supplemented with 60 g/day of mixed nuts (almonds, hazelnuts and walnuts) or their usual nut-free diet for 14 weeks. And now you may ask, why 14 weeks? Well, because that’s the sperm cycle.
Can you explain its main conclusions? I can proudly say that our hypotheses were true. The main results of the study demonstrate that regular nut consumption, in an otherwise imbalanced diet, improved sperm quality parameters such as total sperm count, vitality, motility and morphology and that the findings could be partially explained by a reduction in sperm DNA fragmentation. However, whether our findings can be translated into increased male fertility requires further studies. At this moment in time we can only assume that regular nut consumption improves the quality of sperm. In the same way, we saw other tendencies and statistics in other fields but these also require further studies.
So, could nut consumption help improve male fertility? We demonstrated an improvement in several parameters that could contribute to male fertility. However, we did not analyze fertility by itself. The classical parameters which we found to be beneficially modulated by nut consumption have been linked to increased male fecundability and fertility, but not the novel ones. The study provides evidence for the first time that nuts can have other medical functionalities beyond everything that has already been proved in biomedicine, such as improvements in the field of cardiovascular disease. We have before us an open window. It’s a matter of continuing to investigate
What specifically do nuts contain to potentially increase the number and quality of sperm? Nuts are remarkable for their bioactive compounds. They are high in several components, such as proteins, fiber, fat, MUFA, PUFA, magnesium, vitamin E, omega-3, ALA, omega-6 and are high in substances directly related to anti-inflammatory and anti-oxidant compounds. So, if the hypothesis was that inflammation and oxidation negatively affect fertility, why shouldn’t nuts be beneficial?
What level of daily nut consumption would you recommend to potentially improve sperm count? In our study we used 60 g/day and we did not conduct any dose-response analysis, so we do not have information regarding whether lower doses could bring the same benefits.
Infertility is a major issue nowadays. Are you planning to continue your investigations further in this area? There are still some results derived from the study that deserve further analysis and we will also analyze DNA methylation in more depth in order to identify new potential markers of sperm quality.
What’s the next step? What are the implications of the research? Could this study open the door to new investigations? One of the next steps being studied is the role of DNA methylation in improvements in classic sperm parameters (seminogram). To demonstrate that a food group such as nuts can modulate sperm quality parameters is of great interest in developing public health strategies in developed countries where infertility seems to have fallen drastically. We believe our findings open new avenues for research into how they can be translated into an increase in the chances of fertility and whether nut consumption also has a positive effect on female fertility.
So, would you recommend eating nuts to increase fertility? I would say: Why not? Nuts are rich in beneficial compounds. In this study, we are not saying that they can raise male fertility to 100%, because there are so many other factors to be taken into account, but we have found solid evidence that they improve sperm quality patterns.