Key factors that influence quality of life in patients with IgE-mediated food allergy vary by age.

BACKGROUND: While food allergy (FA) can be fatal, the greatest public health impact of FA arguably lies in its detrimental effect on quality of life (FAQOL). Understanding the factors that contribute to FAQOL at different ages is essential to develop personalized interventions that will improve FAQOL. OBJECTIVE: To determine the most influential factors that impact FAQOL across ages in well-phenotyped participants with confirmed FA. METHODS: One hundred and twenty-five individuals aged 2-28 years with IgE-mediated FA completed validated age-specific FAQOL questionnaires. The relationship between demographic/clinical variables and scores were analyzed to identify key predictors of FAQOL. RESULTS: Poor FAQOL was associated with increasing age, strict avoidance practices, reactions to trace exposures, and more severe reactions as assessed by epinephrine use, anaphylaxis, and/or treatment in the emergency department; FAQOL improved with time from the event. FAQOL was worse in subjects avoiding >2 versus ≤2 foods and in those avoiding milk, egg, soy, sesame, or wheat. Number of foods avoided had greatest impact on children ages 2-7 years, while total number of allergic reactions strongly impacted FAQOL in teens and adults; FAQOL of subjects ages 8-12 years appeared less affected by these variables compared to other age groups. A decision tree analysis identified key predictors of overall FAQOL (age, number of food avoidances, and time since epinephrine use) that can be used to guide intervention strategies to improve FAQOL. CONCLUSION: We directly compared FAQOL in extensively phenotyped children, teenagers, and adults with confirmed IgE-mediated FA. Age; timing, number, and severity of reactions; type and number of FA; and food avoidance practices influence FAQOL and should guide intervention strategies.

LAD2 mast cell activation test associates with the reaction severity and diagnoses BAT nonresponders in Hymenoptera venom allergy.

BACKGROUND AND OBJECTIVE: The usefulness of the mast cell activation test (MAT) in diagnosing patients with uninterpretable basophil activation test (BAT) caused by nonresponding basophils has not yet been addressed. It should be further evaluated if the results of MAT are associated with the severity of the allergic reaction. METHODS: We recruited 39 Hymenoptera venom allergic (HVA) patients, 22 non-sensitized controls, and 37 BAT nonresponding HVA patients. Specific IgE levels for honey bee venom (HBV), yellow jacket venom (YJV) and total IgEs were quantified using the Immulite system. BAT and MAT with LAD2 cells in response to HBV and YJV were performed. RESULTS: We first optimized the susceptibility of LAD2 cells to IgE-mediated degranulation in HVA and showed that prestimulation with IL-33 and IL-6 significantly increased the LAD2 cells´ responsiveness to allergen stimulation (P<0.01). LAD2 MAT results correlated with BAT results, and patients with severe sting reactions (Mueller grades IV or III) had a median 2-fold higher LAD2 MAT than the patients with nonsevere sting reactions (Mueller grades II, I or LLR) (P<0.05). Further, LAD2 MAT provided conclusive results in 54.1% (20 of 37) of HVA patients with nonresponding basophils in the BAT. CONCLUSION: The LAD2 MAT represents a new diagnostic tool for HVA patients with nonresponding basophils. Further, LAD2 MAT can identify patients at risk of severe sting reactions and thus can help guide recommendations for venom immunotherapy and improve the management of patients with HVA.

Understanding Food-Related Allergic Reactions Through a US National Patient Registry.

BACKGROUND: Although previous studies have focused on unintentional food-related allergic reactions, few have explored the motivation of intentional exposure to a known food allergen, independent of oral food challenges and/or oral immunotherapy. Still, data on the frequency and context of food-related allergic reactions remain sparse. OBJECTIVE: To identify the frequency and context of food-related allergic reactions among children and adults. METHODS: We analyzed surveys from the Patient Registry established by Food Allergy Research and Education. Multivariable logistic regression evaluated characteristics associated with having frequent food-related allergic reactions as well as intentional food-related allergic reactions. RESULTS: Over one-third of 4075 (37.7%) respondents reported having more than 1 food-related allergic reaction per year, and 12.8% reported having 1 reaction per year. Of the 3054 respondents who completed the most recent reaction survey, 9.9% of food allergen exposures were classified as intentional, 82.1% as unintentional, and 4.8% as medically related. Among children with intentional exposures, the most common reason was that the child had never had a serious reaction (50.0%), and among adults, it was the decision to take the risk anyway (47.8%). Cross-contamination was the most commonly cited reason for unintentional exposure (children: 24.1%; adults: 32.2%). CONCLUSION: Among patients in a national food allergy registry, reports of food-related allergic reactions were common, and a non-negligible number of intentional reactions were reported. Our findings indicate the need for research on reactions in and out of the emergency department as well as intentional risk-taking behavior.

Dual transcriptomic and epigenomic study of reaction severity in peanut-allergic children.

BACKGROUND: Unexpected allergic reactions to peanut are the most common cause of fatal food-related anaphylaxis. Mechanisms underlying the variable severity of peanut-allergic reactions remain unclear. OBJECTIVES: We sought to expand mechanistic understanding of reaction severity in peanut allergy. METHODS: We performed an integrated transcriptomic and epigenomic study of peanut-allergic children as they reacted in vivo during double-blind, placebo-controlled peanut challenges. We integrated whole-blood transcriptome and CD4+ T-cell epigenome profiles to identify molecular signatures of reaction severity (ie, how severely a peanut-allergic child reacts when exposed to peanut). A threshold-weighted reaction severity score was calculated for each subject based on symptoms experienced during peanut challenge and the eliciting dose. Through linear mixed effects modeling, network construction, and causal mediation analysis, we identified genes, CpGs, and their interactions that mediate reaction severity. Findings were replicated in an independent cohort. RESULTS: We identified 318 genes with changes in expression during the course of reaction associated with reaction severity, and 203 CpG sites with differential DNA methylation associated with reaction severity. After replicating these findings in an independent cohort, we constructed interaction networks with the identified peanut severity genes and CpGs. These analyses and leukocyte deconvolution highlighted neutrophil-mediated immunity. We identified NFKBIA and ARG1 as hubs in the networks and 3 groups of interacting key node CpGs and peanut severity genes encompassing immune response, chemotaxis, and regulation of macroautophagy. In addition, we found that gene expression of PHACTR1 and ZNF121 causally mediates the association between methylation at corresponding CpGs and reaction severity, suggesting that methylation may serve as an anchor upon which gene expression modulates reaction severity. CONCLUSIONS: Our findings enhance current mechanistic understanding of the genetic and epigenetic architecture of reaction severity in peanut allergy.

Pyrolysis behaviors and thermodynamics properties of hydrochar from bamboo (Phyllostachys heterocycla cv. pubescens) shoot shell.

Hydrothermal carbonization (HTC) was employed to produce hydrochar from bamboo (Phyllostachys heterocycla cv. pubescens) shoot shell (BS) at severity (combined temperature and time) of 4.83-7.69. The pyrolysis and thermodynamics properties of the hydrochars were fully investigated. The results showed that the hydrochar properties (solid yield, C content, H/C and O/C atomic ratios, pyrolysis yield, pyrolysis index, formation of enthalpy, exergy, LHV, and HHV) of BS were highly dependent on severity and could be expressed by dose-response functions. The rapid variations of the hydrochar properties appeared at severity of 5.93-6.59. The pyrolysis temperature interval for the maximum weight loss shifted from 300 to 400°C at hydrothermal severity less than 6.59 to 400-500°C at hydrothermal severity greater than 6.59. The hydrochar thermal stability increased greatly with the severity increasing. And the thermodynamic properties of hydrochar approached those of lignin model compounds as the hydrothermal severity was greater than 6.59.

Forecasting the byproducts generated by hydrothermal carbonisation of municipal solid wastes.

The influences of temperature and residence times on the conversion and product distribution during hydrothermal carbonisation of municipal solid wastes were investigated. Analysis of variance and reaction severity were used to comprehensively analyse the experimental results. Analysis results showed both reaction temperature and residence time had varying degrees of impact on production distribution and hydrochars characteristic, while the effect of combine temperature and time was negligible. It is novel to find that the products yield was a linear function of the logarithm of the reaction ordinate. Base on comprehensive consideration, 240 °C to 260 °C and 50 min to 60 min would be the optimised reaction region to achieve relatively better economic benefits for hydrothermal carbonisation of municipal solid waste. By employing the analysis results and estimated models of high heating value and solid yield established in this article, predicting the product characteristics that have not been explored experimentally become possible.

Multisystem reactions during egg oral food challenges may be associated with less severe reactions on initial presentation.

In this study, we assessed whether multisystem reactions to egg and extensively-heated (EH) egg during OFCs were associated with a history of multisystem reactions. Records of children, who underwent OFC to egg or EH egg over a five-year period were reviewed. Of the 120 challenges, 26 (21.67 %) failed, with 38.4 % (10/26) having multisystem reactions. Of the 13 who had multisystem reactions on initial presentation, only two (15.4 %) had a similar OFC outcome. Eighty percent (8/10) of those who had a multisystem OFC reaction had a less severe initial presentation. Initial and OFC multisystem reactions were not associated with each other.

A retrospective analysis of allergic reaction severities and minimal eliciting doses for peanut, milk, egg, and soy oral food challenges.

Food allergy is a public health concern, affecting up to 6% of children and 2% of adults. The severity of allergic reactions can range from mild to potentially life-threatening. In addition, the minimum amount of protein needed to provoke an allergic reaction in an individual patient (the minimal eliciting dose (MED)) ranges from a few micrograms to several grams. To determine whether a retrospective analysis of published data from oral food challenges could be used to assess the potential relationship between MEDs and reaction severities at the MEDs, a three class (mild, moderate, severe) reaction grading system was developed by integrating previously published reaction grading systems. MEDs and symptoms were collected from food challenge studies and each reaction was graded using the integrated grading system. Peanut allergic patients who experienced severe reactions had significantly higher MEDs and threshold distribution doses than those who experienced mild and moderate reactions. No significant differences in threshold distributions according to the severity grading were found for milk, egg and soy. The relationship between threshold dose distribution and reaction severity based on these grading criteria differed between peanut and other allergens, and severe reactions were found to occur in some patients at low MEDs for all of these food allergens.

Cellulose nanocrystals' production in near theoretical yields by 1-butyl-3-methylimidazolium hydrogen sulfate ([Bmim]HSO4)-mediated hydrolysis.

We report on near theoretical yield production of cellulose I nanocrystals (CNCs) using a two-step hydrolysis with the mildly acidic ionic liquid (IL) 1-butyl-3-methylimidazolium hydrogen sulfate ([Bmim]HSO4) in aqueous solution from common cellulosic sources. Two successive Taguchi experimental plans were performed to evaluate the impact of selected reaction parameters (T, t, H2O:IL ratio) and their interactions on the CNCs' yield from bleached softwood kraft pulp (SWP), bleached hardwood kraft pulp (HWP) and microcrystalline cellulose (MCC). With these experimental plans, the molar yield for extraction of nanocrystals was optimized to near theoretical levels, reaching 57.7±3.0%, 57.0±2.0%, and 75.6±3.0%, for SWP, HWP and MCC, respectively. The reaction yields corresponded to a relative crystalline region recovery of 84.1±5.3%, 71.7±1.3%, 76.0±2.0% from SWP, HWP and MCC, respectively. The collected nanocrystals exhibited high aspect ratios (36-43), negligible sulfur content (0.02-0.21%) and high solvent dispersibility in comparison to those obtained with the traditional sulfuric acid method. Additionally these near theoretical yields were achieved for mild reaction conditions with the combined severity factor of 2 and 3 for MCC and pulp, respectively. Overall this two-stage IL-mediated preparation of nanocrystals combines the advantages of achieving high product quality, high reaction yields and mild conditions.