Current Trend in Immunotherapy for Peanut Allergy

Atmospheric cold plasma reduces Ara h 1 antigenicity in roasted peanuts by altering the protein structure and amino acid profile

Ara h 1 is the major allergen in peanuts. To enhance the unique flavor, peanuts are usually roasted at high temperatures. However, roasting can increase the allergenic potential, owing to glycation of allergens. Atmospheric cold plasma (ACP) is a non-thermal processing technology that generates reactive species, enabling protein structural changes. Herein, glucose was also added to the ACP-treated peanut protein before roasting. The content and antigenicity of the advanced glycation end products were measured. The antigenicity was evaluated by ELISA and in vitro digestion assays. The amino acid profile and secondary and tertiary protein structures were also assessed. The antigenicity of Ara h 1 decreased by 91 % and 76 % after 30 min of air and nitrogen plasma treatment, respectively. The glycation degree and thermal and digestive stabilities were also reduced. These results correlated with the structural changes, denaturation, and aggregation. Therefore, cold plasma may reduce the allergic effects of peanuts.

The decrease of Ara h 2 allergenicity by glycation is determined by reducing sugar chain length and isomers

The mechanism of the effect of reducing sugar chain length and isomers on the allergenicity of Ara h 2 after glycation was investigated. Ara h 2 was more prone to glycation with ribose which had a short chain length. The glycation sites of Ara h 2 after glycation with galactose were higher than the glycation sites in galactose's isomers-Ara h 2 conjugates, which might be affected by the configuration differences at position C-4 and the small steric effects in terminal groups -CHO of galactose. Ara h 2-ribose conjugate had the lowest allergenicity, and glycation with galactose was more capable of reducing Ara h 2 allergenicity than its isomers. The results indicated that glycation with ribose caused conformational epitope destruction and linear epitope masking of Ara h 2 greatly. Furthermore, since the small steric effects of -CHO, galactose was more capable of reducing Ara h 2 allergenicity than fructose. This study will provide a theoretical basis for selecting appropriate reducing sugars and preparing hypoallergenic products containing peanuts.

Long Non-Coding RNAs Expressed in the Peanut Allergy for Understanding the Pathophysiology of Peanut Allergy Rat Model

BACKGROUND

Peanut allergy (PA) has become a clinical and public health problem, which is mainly regulated by genetics, immune responses, and environmental factors. Diagnosis and treatment for PA have always remained huge challenges due to its multiple triggers. Studies have shown that long non-coding RNAs (lncRNAs) play a critical role in the development of allergic diseases.

METHOD AND RESULTS

In the current study, we examined the plasma lncRNA expression profiles of peanut allergy Brown Norway rats and healthy controls and 496 differently expressed lncRNAs were identified, including 411 up-regulated genes and 85 down-regulated genes. We screened 8 lncRNAs based on the candidate principle and the candidates were verified in individual samples by quantitative real-time PCR. Then, the four lncRNA-based diagnostic model was established by least absolute shrinkage and selection operator (LASSO) and logistic regression, which was proved by area under the receiver operating characteristic curve (AUC).

CONCLUSIONS

In summary, we assessed the correlation between lncRNA expression levels and the diagnosis of peanut allergy, which may perform a vital role in guiding the management of peanut allergy.

Reducing the Allergenicity of Shrimp Tropomyosin and Allergy Desensitization Based on Glycation Modification

Shrimp is a major allergic food that could trigger severe food allergy, with the most significant and potent allergen of shrimp referred to as tropomyosin (TM). Glycation modification (Maillard reaction) could reportedly weaken the allergenicity of TM and generate hypoallergenic TM, while up to now, there is still a lack of investigations on the hypoallergenic glycated tropomyosin (GTM) as a candidate immunotherapy for desensitizing the shrimp TM-induced allergy. This study analyzed the effects of glycation modification on decreasing the allergenicity of TM and generated hypoallergenic GTM and how GTM absorbed to the Al(OH)₃ function as a candidate immunotherapy for desensitizing allergy. As the results, in comparison to TM, the saccharides of smaller molecular sizes could lead to more advanced glycation end products in GTMs than saccharides of greater molecular sizes, and TM glycated by saccharides of different molecular sizes (glucose, maltose, maltotriose, maltopentaose, and maltoheptaose) exhibited lower allergenicity as a hypoallergen upon activating the allergic reactions of the mast cell and mouse model, while TM glycated by maltose had insignificant allergenicity changes upon activating the allergic reactions of the mast cell and mouse model. In addition, the hypoallergenic GTM + Al(OH)₃ was efficient as a candidate immunotherapy; this work intended to offer preclinical data to promote GTM + Al(OH)₃ as a candidate allergen-specific immunotherapy for desensitizing the allergy reactions for patients allergic to shrimp food.

Correlation between nutritional status and children's activity with food allergy: A cross-sectional study

Background

Food allergy in children affects nutritional status that limits their daily activities to prevent eating various foods to avoid allergic reactions.

Objective

Analyzing the relationship between nutritional status and daily activities in children with food allergies.

Methods

This study used a cross-sectional design that was carried out on children diagnosed with food allergies who underwent outpatient management of food allergies. The data were collected from January to May 2021 that included participant characteristics, nutritional status, and daily activities. Data analysis used Chi-Square and spearman rho test with p < 0.05.

Results

There was a significant relationship between age and FAIS (CI 1.83-4.24; p = 0.025). In addition, there was no significant relationship between the affected organs and FAIS (OR = 0.174; p = 0.052). Meanwhile, the relationship between nutritional status and FAIS was significant (OR = 0.161; p = 0.007). There was no significant relationship between parental education and FAIS (OR = 0.817; p = 0.776) as well as sex of the child and FAIS (OR = 0.982; p = 0.977).

Conclusion

Daily activities of children with food allergies are influenced by the nutritional status of children and children's age in choosing food.

Investigation of glycated shrimp tropomyosin as a hypoallergen for potential immunotherapy

Tropomyosin (TM) is the most important allergen in shrimps that could cause food allergy. Glycation is reported to be effective in reducing TM allergenicity and produce hypoallergen; however, up to now, there are very few reports on the potential of hypoallergenic glycated TM (GTM) as allergen immunotherapy for shrimp TM-induced food allergy. This study investigated the glycation of TM-produced hypoallergen and the immunotherapeutic efficacy of GTM + Al(OH)₃ as potential allergen immunotherapy. Compared to TM, the TM glycated by glucose (TM-G), maltotriose (TM-MTS), maltopentaose (TM-MPS) and maltoheptaose (TM-MHS) had weaker allergy activation on mast cells and mouse model as a hypoallergen. However, the TM glycated by maltose (TM-M) insignificantly affected the allergenicity. In addition, the GTM absorbed into Al(OH)₃ could be efficacious as potential allergen immunotherapy, particularly for the TM glycated by the saccharides having larger molecular size (e.g., TM-MHS), which could provide preclinical data to develop GTM + Al(OH)₃ as a candidate immunotherapy for shrimp allergic patients.

Global Trends and Future Prospects of Child Nutrition: A Bibliometric Analysis of Highly Cited Papers

Child nutrition has always been a global concern. This study performed visual analysis of 1,398 child nutrition highly cited papers (HCPs) from 2009 to 2019. The purpose of the study was to evaluate and present the performances of authors, journals, countries, institutions, top cited papers; to explore the hot topics, prospects, and to propose the future research directions on child nutrition. We used bibliometric methods to conduct in-depth statistical analysis of HCPs on child nutrition, showing research progress, trends and hot spots. We included HCPs on child nutrition from the Science Citation Index-Expanded (SCI-E) database February 7, 2020. Two tools, CiteSpace and VOSviewer, were used to conduct the bibliometric analyses. The results showed that, since 2011, the number of HCPs on child nutrition has increased rapidly. The top three contributors in this field were the USA, the UK and Canada. However, the contribution of developing countries was very limited. Intestinal microflora, food allergy, overweight and obesity were the three major research hotspots in this field. Results of this study provide valuable references for ongoing child nutrition related research, which may be interesting and noteworthy to the researchers involved.

Eosinophilic Esophagitis as a Side Effect of Food Oral Immunotherapy

Food allergies (FAs) include a spectrum of immune-mediated serious and potentially life-threatening medical conditions with an overall estimated prevalence ranging from 4% to 8% in the U.S. and Europe. Significant progress in food allergen-specific immunotherapy has been accomplished over the past 10 years. The most studied strategy has been oral immunotherapy (OIT), also known as food desensitization, a treatment in which a child is slowly and deliberately given a small amount of the food to ingest (that previously was a food allergy trigger) with the ultimate goal of the child eating that food without a reaction. OIT is now recommended in the European guidelines for the treatment of milk, egg, and peanut allergies and was the first American Food Drug Administration (FDA) approved product for the prevention of severe reaction to peanuts in 4–17 year olds to be released on the market. The side effects associated with OIT treatment trials are mild to moderate, predominantly oropharyngeal, and easily treated. More severe reactions, such as generalized urticaria/angioedema, wheezing/respiratory distress, laryngeal edema, and repetitive emesis, have been reported. However systemic reactions are very rare. Low-dose immunotherapy is associated with significantly fewer side effects. Currently, its most limiting allergic side effect is that approximately 10–15% of subjects treated with OIT experience gastrointestinal symptoms, preventing the continuation of therapy. Eosinophilic esophagitis (EoE) has also been reported as a cause of persistent abdominal symptoms in OIT.

Peanut allergy impact on productivity and quality of life (PAPRIQUA): Caregiver-reported psychosocial impact of peanut allergy on children

BACKGROUND

Limited research has examined the impact of peanut allergy (PA) on children using validated instruments to assess psychosocial burden and the factors influencing burden.

OBJECTIVE

The PAPRIQUA study aimed to assess the caregiver-reported impact of living with PA on children's health-related quality of life (HRQL), correlations between PA severity and child's sex, and associations of caregivers' sex and anxiety with the proxy report of their child's HRQL and to identify significant predictors of a child's HRQL.

METHODS

A cross-sectional survey of caregivers of children with mild, moderate and severe PA, based on caregiver perception, was conducted in the United Kingdom. Participants were recruited through a survey recruitment panel; a maximum quota of 20% who rated their child's PA as mild was set to ensure population diversity; however, the quota was not required as few participants considered their child's PA mild. The survey, funded by Aimmune Therapeutics, included sociodemographic and clinical questions, the EQ-5D-Y, Hospital Anxiety and Depression Scale, Food Allergy Quality of Life Questionnaire-Parent Form (FAQLQ-PF) and Food Allergy Independent Measure (FAIM).

RESULTS

One hundred caregivers of children with PA (aged 4-15 years) completed the survey. Child's sex was not associated with proxy-reported burden. For younger children (aged 4-10 years), there was no effect of PA severity; parents of older children (aged 11-15 years) reported low to higher burden for their child on the EQ-5D-Y and FAQLQ-PF dependent upon PA severity. For all measures of child burden except the EQ-5D-Y, two or more reactions in the past 12 months and parental anxiety significantly predicted higher levels of burden for the child (P < .05-P < .001). Experiencing a life-threatening event in the past 12 months significantly predicted EQ-5D-Y proxy utility (P < .01).

CONCLUSIONS AND CLINICAL RELEVANCE

Caregivers report that children with PA experience high levels of psychosocial burden, particularly those with more severe PA and a reaction history. Interventions to decrease caregiver anxiety and reaction frequency may help reduce the child's burden. Self-report studies in children with PA would help confirm these findings.

Multiple drug allergies: Recommendations for perioperative management

Life-threatening hypersensitivity reactions are more likely to occur in patients with a history of allergy, atopy, or asthma. Hence, in a patient who presented with a history of multiple drug allergies (MDA), an allergological assessment should be performed prior to surgical procedure. Drug allergies, being one of the causes of catastrophic events occurring in the perioperative period, are of major concern to anesthesiologists. Neuromuscular blocking agents are regularly used during anesthesia and are one of the most common causes of perioperative anaphylaxis. They are estimated to be responsible for 50%-70% of perioperative hypersensitivity reactions. Antibiotics and latex represent the next two groups of drug allergy. Allergic reactions to propofol are rare with an incidence of 1:60,000 exposures. Although intraoperative drug anaphylaxis is rare, it contributes to 4.3% of deaths occurring during general anesthesia. These recommendations discuss pathophysiology of MDA, preoperative evaluation, and anesthesia considerations as well as the prevention and management of allergic reactions in anesthetized patients with a history of MDA.

Oral desensitization in IgE-mediated food allergy: Effectiveness and safety

The avoidance of allergenic foods and emergency medications on accidental exposure are the only currently approved treatments in food allergy. EAACI guideline on allergen immunotherapy recommends oral immunotherapy as a therapeutic option to increase the threshold of the reaction during treatment in children with persistent IgE-mediated cow's milk, hen's egg, and peanut allergy from around 4-5 years of age, but the same recommendation cannot currently be made to achieve post-discontinuation effectiveness. Both systemic and local reactions during OIT have been frequently reported. For this reason, EAACI guideline suggests several recommendations on safety, including carefully monitoring patients for allergic reactions, especially during the up-dosing phase of OIT, and monitoring for symptoms of new-onset eosinophilic esophagitis. New approaches are certainly necessary to give priority not only to effectiveness but also to safety.

Progress in the Analysis of Food Allergens through Molecular Biology Approaches

Food allergies associated with class E immunoglobulins (IgE) are a serious health problem that affects between 1% and 10% of the population of developing countries, with a variability that depends on the geographical area and age range considered. These allergies are caused by a cross-link reaction between a specific food protein (the allergen) and the host IgE. Allergic reactions can range from mild itching to anaphylactic shock and there are no clues to predict the effects of an allergen. Strict avoidance of allergenic food is the only way to avoid possible serious allergic reactions. In the last 30 years a growing number of molecular studies have been conducted to obtain information on the diffusion of food allergens and to establish the structural basis of their allergenicity. At the same time, these studies have also allowed the development of molecular tools (mainly based on synthetic peptides and recombinant allergens) that can be of great help for diagnostic and therapeutic approaches of food allergies. Accordingly, this review focuses on advances in the study of food allergens made possible by molecular technologies and how results and technologies can be integrated for the development of a systematic food molecular allergology. The review may be of interest both to scientists approaching this field of investigation and to physicians who wish to have an update on the progress of research in diagnosis and therapy of food allergies.