Common Food Allergies Research Articles

Assessment of Clinicopathological Features in Infants and Children with Cow�s Milk Protein Allergy

The aim of our study was to evaluate the clinicopathological features in infants and young children with cow�s milk protein allergy. Cow�s milk protein allergy (CMPA) is one of the most common food allergy in children. Thus, we conducted a descriptive observational study, which was carried out in the First Pediatric Clinic of the Craiova County Emergency Clinical Hospital, in the period 2015-2017, which included 138 infants and young children diagnosed with cow�s milk protein allergy. An improvement in digestive symptomatology during the status period of the disease was observed, especially in what diarrheal stools are concerned as their incidence has decreased. In fact, gastroesophageal reflux is the most common manifestation in infants and children with CMPA, while mean acute otitis is present only in a small number of patients. In conclusion we can say that a good knowledge of the clinicopathological features in children with allergy to cow�s milk proteins allows a superior therapeutic attitude and ensures a normal life for children and infants suffering from this type of allergy.

Parte 1: Alergia a la proteína de leche de vaca

La alergia a la proteína de leche de vaca (APLV) es la alergia alimentaria más frecuente en niños menores de 3 años, con una incidencia estimada entre 2-7.5%. Comprende reacciones mediadas IgE, no mediadas por IgE y mixtas. La APLV involucra tres sistemas: respiratorio, gastrointestinal y piel. Su diagnóstico es clínico y se conforma o excluye con la eliminación del alérgeno. Si el lactante es alimentado con leche materna la madre debe continuar con su administración, evitando alimentos que contengan proteína de leche de vaca y ella deberá recibir suplementos de calcio 1000 mg al día. Si recibe fórmula artificial, ésta debe ser eliminada e iniciar una fórmula extensamente hidrolizada. Dado que cada día la APLV está incrementando a edades mayores y observamos un aumento en la severidad, decidimos realizar la presente revisión y dar a conocer los factores de riesgo involucrados, para hacer un diagnóstico precoz y evitar así el compromiso sobre el estado nutricional, ya que por desconocer estos, la mayoría de los niños son sometidos a cambios frecuentes de fórmulas y eliminaciones dietéticas innecesarias. Palabras clave Hipersensibilidad a los alimentos, hipersensibilidad a la leche, lactancia materna

Wheat allergy – clinical implications and management

Grain allergies are common food allergies, that are typically but not only seen in individuals with other associated food allergies. The immunologic responses to grain proteins can be IgE and/or non-IgE mediated. Wheat allergy is the most common of the cereal grain allergies. It usually begins in early childhood and is outgrown by adolescence, although some retain it beyond the teenage years. Immunoglobulin E (IgE)-mediated wheat allergy is reported to affect 0.2 to 1.3 percent of children in Europe and 0.4 percent of children in the United States. The onset of wheat allergy in adulthood is typically not seen, unless it is related to an occupational exposure. Epidemiologic data for the other grains is largely missing. Immunoglobulin E (IgE)-mediated food-triggered reactions generally occur immediately, within minutes to two hours after ingestion. These reactions can present with skin, oropharyngeal, upper and lower respiratory tract, gastrointestinal tract, and/or cardiovascular signs and symptoms. The reactions can vary from mild cutaneous reactions to life-threatening anaphylaxis. Positive diagnose is based on determining the plasmatic level of specific IgE and performing skin prick test for wheat, methods that have poor specificity and sensitivity in predicting oral food challenge test outcomes. The gold standard test remains oral food challenge (OFC) test for wheat. Most of the studies have proven its utility, even in children with high levels of wheat specific IgE. The diagnose of non-IgE mediated reactions is based on clinical presentation and plasmatic levels of specific antibodies, other than IgE. The management of grain allergy does not differ from that of other food allergies. It requires instructions on avoidance and treatment of reactions in the event of accidental exposure. It includes education about grain alternatives. It also includes monitoring for nutritional issues and for the resolution of the allergy. Preliminary data on specific oral tolerance induction to wheat through oral desensitization protocols have shown some promise in children, but it is still considered an experimental therapy.

IgE-mediated cow’s milk protein allergy in Singaporean children

Cow's milk protein allergy (CMA) is the second most common food allergy in Singapore. However, there is limited data on local paediatric CMA. We aimed to describe the demographics, clinical characteristics, natural history and diagnostic performance of skin prick test (SPT) and cow's milk-specific immunoglobulin E (CM-IgE) in Singaporean children diagnosed with IgE-mediated CMA. A retrospective review of medical records was conducted for children with an SPT performed to cow's milk between 2011 and 2016. There were 355 patients included, 313 cow's milk allergic and 42 cow's milk tolerant. The median age of reaction was 6 months (IQR 4-8). The most common allergic presentation was cutaneous reactions, followed by gastrointestinal reactions. Six patients (1.9%) reported anaphylaxis at initial presentation and 16 children (5.1%) experienced anaphylaxis to cow's milk at least once in their lifetime. Most of the CMA patients (81.8%) acquired natural tolerance by 6 years old. SPT to cow's milk of ≥ 7 mm and CM-IgE of ≥ 13 kU/L showed good discriminative abilities in predicting a failed oral food challenge (OFC) outcome. CMA is a food allergy which commonly presents during infancy, and parents need to be aware of the likelihood of severe allergic reactions, including anaphylaxis. Prognosis for CMA is generally favourable. Future prospective cohort studies are required to better understand the natural history and better define the diagnostic cut-off values for allergy testing in our population.

Oral allergy syndrome amongst young Mexicans: prevalence and associated factors.

Background. Oral allergy syndrome (OAS) is the most common food allergy manifestation amongst adults. However, population studies aimed at estimating its prevalence and associated factors are scarce in Mexi-co. Objectives. To establish the prevalence of OAS in a sample of university students and to describe their clinical characteristics and its associated factors. Methods. From a sample group made up of 25,269 university students, the data corresponding to 1,200 students aged 18 to 25 was analyzed with a cross-sectional approach. A structured questionnaire was used to identify OAS, its symptoms and related foods, and the personal history of atopic diseases. The associations between variables were calculated through logistical regression analysis. Results. The prevalence of OAS was 3.4%, with a 95% confidence interval (95% CI) of 2.5 to 4.6. The main oral symptoms reported were lip pruritus, edema and the sensation of pharyngeal oppression. Among the extra-oral complaints were: reddish coloration of the skin, body pruritus, abdominal pain, and abdominal bloating. The foods that were most frequently associated with OAS were fruits (68.5%), vegetables (22.0%) and seafood (19.3%). Through multivariate analyses, allergy to pollen and latex were found to be associated with OAS, OR 3.29; 95%: CI 1.53 to 7.10 and OR 5.53; 95% CI: 1.08 to 28.2, respectively. Conclusions. Notably, the prevalence of OAS varies according to the geographic area. Personal histories of allergy to pollen or latex were the main factors linked to OAS.

Palatability of hypoallergenic formulas for cow's milk allergy and healthcare professional recommendation.

Cows 'milk protein allergy (CMPA) is the most common food allergy in infants in the United Kingdom. Infants with CMPA who are not exclusively breastfed require a substitute hypoallergenic formula, which are perceived as having a poor palatability. This study compares the palatability of different extensively hydrolysed formulas (EHFs) and explores healthcare professional (HCP) expectations of how palatability impacts infants and their families. Healthcare professional with experience of CMPA were recruited to take part in a home palatability test of four EHFs [Aptamil Pepti 1, Nutricia Ltd. (EHF W1); Althera, Nestle Health Science (EHF W2); Similac Alimentum, Abbott (EHF C1); Nutramigen LGG 1, Mead Johnson (EHF C2)] using a blind taste procedure. A randomised, complete block design was used to minimise order and carry-over biases. Participants completed a questionnaire about the impact of formula palatability on infants and their families. A total of 100 HCPs took part (51 dietitians and 49 general practitioners). Overall, whey-based lactose-containing EHFs were ranked the most palatable: EHF W1 by 77% of participants and EHF W2 by 20%. EHF W1 was liked significantly more (P<0.0001) than the other formulas. The vast majority of participants agreed that better palatability would result in an increased chance of non-rejection (96%), more content families (92%) and decreased healthcare costs (90%). Amongst HCPs who manage infants with CMPA, whey-based lactose-containing EHFs were ranked the most palatable. HCPs expected that good palatability would result in better acceptance, more content infants and families, alongside decreased wastage and healthcare costs.

Egg allergen specific IgE diversity predicts resolution of egg allergy in the population cohort HealthNuts.

IgE-mediated egg allergy presents as one of the most common food allergies in children. Measurement of egg white specific IgE (sIgE) levels in serum or skin prick test has been shown to be a poor predictor of clinical allergy to raw egg white, and also to baked or cooked egg. Recent developments in component resolved diagnostic (CRD) technology have enabled us to improve the way in which we diagnose and predict peanut allergy by examining IgE specificity to individual peptides. We aimed to investigate whether egg CRD could improve current methods to diagnose various egg allergy phenotypes as well as predict the development of tolerance to egg. Using the HealthNuts cohort of food challenge-proven egg allergic and egg-sensitized and egg-tolerant, age-matched 12-month infants with longitudinal follow-up at 2 and 4years (n=451), we measured serum egg white, Gal d 1, 2, 3 and 5 sIgE using ImmunoCAP. Gal d 1 sensitization increased the risk of persistent egg allergy by 2.5-fold. The production of sIgE to all four egg allergens (Gal d 1, 2, 3 or 5) increased the risk of having persistent raw egg allergy fourfold (OR 4.19 (95% CI: 1.25-14.07). We did not find any improvements of using Gal d 1, 2, 3 or 5 to diagnose current egg allergy compared to egg white sIgE. Sensitization to multiple egg allergens Gal d 1, 2, 3 or 5 may be a prognostic marker that could be useful for patient management and identifying individuals at risk of developing persistent egg allergy.

THE EPIDEMIOLOGY OF MILK ALLERGY IN US CHILDREN: AN UPDATE

Introduction Cow's milk allergy is the second most common food allergy (FA) in children. This study looks at the epidemiological pattern of childhood milk allergy in the US, including diagnosis, symptoms, severity, and tolerance to baked milk. Methods A randomized, cross-sectional survey was administered to 53,575 parents from a representative sample of US households with children from October 2015 to September 2016. Data regarding demographics, allergic symptoms and severity, diagnosis, and baked milk tolerance were collected and analyzed as weighted proportions. Adjusted models were estimated to examine association of these factors with odds of milk allergy. Results In our US population sample, 1.9% of children have a convincing milk allergy. Amongst children with food allergy, milk allergy was found in 53.0% of infants ( Conclusions Milk is the most common food allergen in children under age 5, with over half of infants with FA reporting allergy to milk. Although 1 in 4 children with milk allergy sought emergency treatment over the last 12 months, less than half had their milk allergy diagnosed by a physician. Cow's milk allergy is the second most common food allergy (FA) in children. This study looks at the epidemiological pattern of childhood milk allergy in the US, including diagnosis, symptoms, severity, and tolerance to baked milk. A randomized, cross-sectional survey was administered to 53,575 parents from a representative sample of US households with children from October 2015 to September 2016. Data regarding demographics, allergic symptoms and severity, diagnosis, and baked milk tolerance were collected and analyzed as weighted proportions. Adjusted models were estimated to examine association of these factors with odds of milk allergy. In our US population sample, 1.9% of children have a convincing milk allergy. Amongst children with food allergy, milk allergy was found in 53.0% of infants ( Milk is the most common food allergen in children under age 5, with over half of infants with FA reporting allergy to milk. Although 1 in 4 children with milk allergy sought emergency treatment over the last 12 months, less than half had their milk allergy diagnosed by a physician.

Successful oral desensitization in children with cow's milk anaphylaxis: Clinical and laboratory evaluation up to nine-years follow-up

IntroductionCow's milk protein allergy (CMPA) is the most common food allergy in children worldwide. Some children have severe and persistent CMPA, with near-fatal reactions after exposure to trace amounts of cow's milk-proteins (CMP). Strict avoidance diet is difficult, negatively affects quality of life and represents a conservative approach. Therefore, different therapeutic strategies are necessary. ObjectiveWe aimed to assess long-term efficacy and safety of oral immunotherapy (OIT) in children with severe and long-lasting IgE-mediated CMPA. Materials and methodsThe authors present four case reports of patients with CMPA who underwent CMP-OIT, that have been under long-term follow-up up to nine years. We provide information about the clinical and laboratory evaluation. Skin prick tests (SPT), specific IgE and IgG4 were performed before, during, and after OIT. Immune profile after OIT was assessed by flow cytometry (lymphocyte subsets, regulatory T and B cells). ResultsThe success rate was 100%, and all patients currently have a free diet with minimal diary ingestion of 200mL CMP or equivalent. Specific IgE levels and SPT to CMP have progressively decreased, and specific IgG4 levels have increased. CD4+CD25+CD127−/dim regulatory T cells were increased after OIT. ConclusionsOIT ensured a clinical tolerance state after up to nine years, confirmed by both clinical and immune profile, allowing a diet without restrictions, with high satisfaction from patients and caregivers. We emphasize that OIT should be performed only by allergy experts in the hospital setting, and that only motivated families should be enrolled, since it is essential to ensure CMP daily intake at home.

Microbiota and Derived Parameters in Fecal Samples of Infants with Non-IgE Cow's Milk Protein Allergy under a Restricted Diet.

Cow’s milk protein allergy (CMPA) is the most common food allergy in infancy. Non-IgE mediated (NIM) forms are little studied and the responsible mechanisms of tolerance acquisition remain obscure. Our aim was to study the intestinal microbiota and related parameters in the fecal samples of infants with NIM-CMPA, to establish potential links between type of formula substitutes, microbiota, and desensitization. Seventeen infants between one and two years old, diagnosed with NIM-CMPA, were recruited. They were all on an exclusion diet for six months, consuming different therapeutic protein hydrolysates. After this period, stool samples were obtained and tolerance development was evaluated by oral challenges. A control group of 10 age-matched healthy infants on an unrestricted diet were included in the study. Microbiota composition, short-chain fatty acids, calprotectin, and transforming growth factor (TGF)-β1 levels were determined in fecal samples from both groups. Infants with NIM-CMPA that consumed vegetable protein-based formulas presented microbiota colonization patterns different from those fed with an extensively hydrolyzed formula. Differences in microbiota composition and fecal parameters between NIM-CMPA and healthy infants were observed. Non-allergic infants showed a significantly higher proportion of Bacteroides compared to infants with NIM-CMPA. The type of protein hydrolysate was found to determine gut microbiota colonization and influence food allergy resolution in NIM-CMPA cases.

The Epidemiology of Food Allergy in the Global Context.

There is a lack of high-quality evidence based on the gold standard of oral food challenges to determine food allergy prevalence. Nevertheless, studies using surrogate measures of food allergy, such as health service utilization and clinical history, together with allergen-specific immunoglobulin E (sIgE), provide compelling data that the prevalence of food allergy is increasing in both Western and developing countries. In Western countries, challenge-diagnosed food allergy has been reported to be as high as 10%, with the greatest prevalence noted among younger children. There is also growing evidence of increasing prevalence in developing countries, with rates of challenge-diagnosed food allergy in China and Africa reported to be similar to that in Western countries. An interesting observation is that children of East Asian or African descent born in a Western environment are at higher risk of food allergy compared to Caucasian children; this intriguing finding emphasizes the importance of genome-environment interactions and forecasts future increases in food allergy in Asia and Africa as economic growth continues in these regions. While cow’s milk and egg allergy are two of the most common food allergies in most countries, diverse patterns of food allergy can be observed in individual geographic regions determined by each country’s feeding patterns. More robust studies investigating food allergy prevalence, particularly in Asia and the developing world, are necessary to understand the extent of the food allergy problem and identify preventive strategies to cope with the potential increase in these regions.

Gut microbiota composition and butyrate production in children affected by non-IgE-mediated cow\u2019s milk allergy

Cow’s milk allergy (CMA) is one of the earliest and most common food allergy and can be elicited by both IgE- or non-IgE-mediated mechanism. We previously described dysbiosis in children with IgE-mediated CMA and the effect of dietary treatment with extensively hydrolyzed casein formula (EHCF) alone or in combination with the probiotic Lactobacillus rhamnosus GG (LGG). On the contrary, the gut microbiota in non-IgE-mediated CMA remains uncharacterized. In this study we evaluated gut microbiota composition and fecal butyrate levels in children affected by non-IgE-mediated CMA. We found a gut microbiota dysbiosis in non-IgE-mediated CMA, driven by an enrichment of Bacteroides and Alistipes. Comparing these results with those previously obtained in children with IgE-mediated CMA, we demonstrated overlapping signatures in the gut microbiota dysbiosis of non-IgE-mediated and IgE-mediated CMA children, characterized by a progressive increase in Bacteroides from healthy to IgE-mediated CMA patients. EHCF containg LGG was more strongly associated with an effect on dysbiosis and on butyrate production if compared to what observed in children treated with EHCF alone. If longitudinal cohort studies in children with CMA will confirm these results, gut microbiota dysbiosis could be a relevant target for innovative therapeutic strategies in children with non-IgE-mediated CMA.

Most children who are allergic to cow's milk tolerate yogurt.

ObjectiveCow’s milk allergy is the most common food allergy in childhood. Changes occur in the protein structure of milk during yogurt fermentation. This study aimed to determine whether children who are diagnosed with a cow’s milk allergy can tolerate yogurt.MethodsWe performed a yogurt challenge test on 34 children who were diagnosed with a cow’s milk allergy in our Pediatric Allergy Outpatient Clinic. The mean age of 24 male and 10 female children was 24 ± 13 months.ResultsA reaction was observed in 17 (50%) patients, whereas no reaction was observed in the other 17 (50%) during an oral yogurt challenge test that was performed in all of the 34 patients with a cow’s milk allergy. Cow’s milk-specific immunoglobulin E levels were significantly lower in the group of children who could tolerate yogurt than in the group of children who could not tolerate yogurt.ConclusionYogurt is tolerated by half of children with a cow’s milk allergy when subjected to a challenge test performed with yogurt, which is consumed as much as milk in Turkey.

Study of Specific IgE and IgG4 Levels Regarding the Acquisition of Tolerance in Patients Allergic to Eggs

In recent decades we have witnessed an increase in allergic diseases in general, and food allergy in particular, which is the most common cause of anaphylaxis in children. In our midst, in the small child, egg allergy is the most common food allergy followed by cow's milk and fish.

Predictors of Persistent Wheat Allergy in Children: A Retrospective Cohort Study

Background: Wheat allergy is the third most common food allergy that develops during infancy in Japan. To identify factors associated with persistent wheat allergy, we assessed the rate of tolerance acquisition among Japanese children aged less than 6 years with an immediate-type wheat allergy using the oral food challenge (OFC) method. Methods: This retrospective cohort study included 83 children (born in 2005–2006) who had a history of immediate-type allergic reaction to wheat and were followed until 6 years of age. The subjects were divided to form “tolerant” (n = 55; tolerance acquired by 6 years of age) and “allergic” (n = 28; tolerance not acquired by 6 years of age) groups based on their OFC results. Results: The rates of tolerance acquisition to 200 g of udon noodles at 3, 5, and 6 years of age were 20.5% (17/83), 54.2% (45/83), and 66.3% (55/83), respectively. The total number of anaphylactic reactions experienced prior to 3 years of age in response to all foods (p < 0.01) and to wheat (p = 0.043) was significantly higher in the allergic than in the tolerant group. Wheat- and ω-5 gliadin-specific immunoglobulin E (IgE) levels were significantly higher in the allergic group than in the tolerant group (p < 0.01), and wheat-specific IgE levels were more likely to increase after infancy in the allergic group. Conclusions: A history of anaphylaxis to all foods including wheat and/or a high level of wheat- or ω-5 gliadin-specific IgE antibodies were identified as risk factors for persistent wheat allergy.

Non-Ige-Mediated Cow's Milk Protein Allergy Presenting with Generalized Edema: Case Report and Review of the Literature

Cow's milk protein allergy (CMPA) is the most common food allergy in young children. A 40-day-old boy on regular formula presented with generalized edema and chronic watery diarrhea since birth. Laboratory data revealed serum albumin at 0.9 g/dL, and urine analysis did not reveal proteinuria. Echocardiogram was normal. CMPA was diagnosed based on history and rapid response to amino-acid-based infant formula (Neocate®). At the infant’s last follow-up examination at 24 months, he was thriving on a regular diet, with normal growth.

Prevalence of cow's milk protein allergy among children in a university community hospital.

Cow's milk protein allergy (CMPA) is the most common food allergy in pediatrics. In Argentina, the prevalence of this disease has been evaluated in a few trials. To estimate the prevalence of CMPA and describe its variation throughout a period of 11 years. A retrospective cohort study was carried out in live newborn infants enrolled in a health care program of a university community hospital. One hundred and sixteen cases of children with CMPA were identified. Cumulative prevalence was 0.8% (95% confidence interval [CI]: 0.65-0.95). A percent increase of 0.4% in 2004 to 1.2% in 2014 was observed in the number of cases per year. In 2014, CMPA prevalence was 1.2%, i.e. three times that of 2004.

Oral and sublingual immunotherapy for egg allergy.

Clinical egg allergy is a common food allergy. Current management relies upon strict allergen avoidance. Oral immunotherapy might be an optional treatment, through desensitization to egg allergen. To determine the efficacy and safety of oral and sublingual immunotherapy in children and adults with immunoglobulin E (IgE)-mediated egg allergy as compared to a placebo treatment or an avoidance strategy. We searched 13 databases for journal articles, conference proceedings, theses and trials registers using a combination of subject headings and text words (last search 31 March 2017). We included randomized controlled trials (RCTs) comparing oral immunotherapy or sublingual immunotherapy administered by any protocol with placebo or an elimination diet. Participants were children or adults with clinical egg allergy. We retrieved 97 studies from the electronic searches. We selected studies, extracted data and assessed the methodological quality. We attempted to contact the study investigators to obtain the unpublished data, wherever possible. We used the I² statistic to assess statistical heterogeneity. We estimated a pooled risk ratio (RR) with 95% confidence interval (CI) for each outcome using a Mantel-Haenzel fixed-effect model if statistical heterogeneity was low (I² value less than 50%). We rated the quality of evidence for all outcomes using GRADE. We included 10 RCTs that met our inclusion criteria, that involved a total of 439 children (oral immunotherapy 249; control intervention 190), aged 1 year to 18 years. Each study used a different oral immunotherapy protocol; none used sublingual immunotherapy. Three studies used placebo and seven used an egg avoidance diet as the control. Primary outcomes were: an increased amount of egg that can be ingested and tolerated without adverse events while receiving allergen-specific oral immunotherapy or sublingual immunotherapy, compared to control; and a complete recovery from egg allergy after completion of oral immunotherapy or sublingual immunotherapy, compared to control. Most children (82%) in the oral immunotherapy group could ingest a partial serving of egg (1 g to 7.5 g) compared to 10% of control group children (RR 7.48, 95% CI 4.91 to 11.38; RD 0.73, 95% CI 0.67 to 0.80). Fewer than half (45%) of children receiving oral immunotherapy were able to tolerate a full serving of egg compared to 10% of the control group (RR 4.25, 95% CI 2.77 to 6.53; RD 0.35, 95% CI 0.28 to 0.43). All 10 trials reported numbers of children with serious adverse events (SAEs) and numbers of children with mild-to-severe adverse events. SAEs requiring epinephrine/adrenaline presented in 21/249 (8.4%) of children in the oral immunotherapy group, and none in the control group. Mild-to-severe adverse events were frequent; 75% of children presented mild-to-severe adverse events during oral immunotherapy treatment versus 6.8% of the control group (RR 8.35, 95% CI 5.31 to 13.12). Of note, seven studies used an egg avoidance diet as the control. Adverse events occurred in 4.2% of children, which may relate to accidental ingestion of egg-containing food. Three studies used a placebo control with adverse events present in 2.6% of children. Overall, there was inconsistent methodological rigour in the trials. All studies enrolled small numbers of children and used different methods to provide oral immunotherapy. Eight included studies were judged to be at high risk of bias in at least one domain. Furthermore, the quality of evidence was judged to be low due to small numbers of participants and events, and possible biases. Frequent and increasing exposure to egg over one to two years in people who are allergic to egg builds tolerance, with almost everyone becoming more tolerant compared with a minority in the control group and almost half of people being totally tolerant of egg by the end of treatment compared with 1 in 10 people who avoid egg. However, nearly all who received treatment experienced adverse events, mainly allergy-related. We found that 1 in 12 children had serious allergic reactions requiring adrenaline, and some people gave up oral immunotherapy. It appears that oral immunotherapy for egg allergy is effective, but confidence in the trade-off between benefits and harms is low; because there was a small number of trials with few participants, and methodological problems with some trials.

Egg white component-resolved diagnosis: Testing of serum ovalbumin-specific IgE by luminescent oxygen channeling immunoassay

Egg allergy is the second most common food allergy in children. Precise measurement of allergen component-specific IgE (sIgE) in serum contributes to molecular diagnosis of egg allergy, i.e. component-resolved diagnosis (CRD). Existing CRD methods, including ImmunoCAP and Immulite, have unavoidable drawbacks such as errors from solid-liquid phase separation and enzyme instability. Therefore, we take egg allergen ovalbumin as an example to establish a homogenous method−indirect luminescent oxygen channeling immunoassay (LOCI) to determine ovalbumin-sIgE precisely. In the indirect LOCI reaction system, ovalbumin-conjugated acceptor nanoparticles were brought close to streptavidin-conjugated donor nanoparticles through antigen-antibody and biotin-streptavidin interactions. The optimal conditions for LOCI were 16.67 μg/mL acceptor-ovalbumin, 1.047 μg/mL biotinylated anti-human IgE antibodies and a 1/20 dilution of serum in a 25-μL reaction volume for a 45-min incubation. We assessed the performance of of this LOCI system, including sensitivity, precision, and anti-interference ability, and compared the diagnostic performance of the LOCI with enzyme-linked immunosorbent assay (ELISA) through a receiver operator characteristic (ROC) analysis. Results revealed that LOCI was superior to ELISA in performance. In summary, we demonstrated that indirect LOCI was an excellent method for precise determination of allergen component-sIgE, contributing to CRD of food allergy.

Nutritional and allergenic properties of hen eggs

Chicken eggs, along with cow milk, are the most important source of proteins and other valuable nutrients that are introduced to a baby`s diet. Certain components of eggs, besides nutritional, also have other biological functions. Both proteins, phospholipids or carotenoids, are bioactive components which affect the physiological processes in the human body. Regular consumption of chicken eggs rich in substances with antibacterial, anti-inflammatory, immunomodulatory and antioxidant properties may contribute to reducing the incidence of certain lifestyle diseases. Ovomucoid, as a glycoprotein which inhibits bacterial protease, is a component of eggs with bactericidal properties. Similarly, the ovotransferrin protein has a bacteriostatic effect on the Escherichia coli strain or Streptococcus mutans. Due to the strong antioxidant properties, phospholipids, vitamin E and folic acid are extremely valuable egg components. It is believed that the high antioxidant potential of these compounds is important in preventing the development of atherosclerosis and other metabolic syndromes. It is also worth mentioning lutein and zeaxanthin, which are dyes that form a protective barrier against the degeneration of the macula of the human eye. An extremely important function for the human immune system is also met by lysozyme, which stimulates the synthesis of interferon, stimulating the immune response. Unfortunately, hypersensitivity to chicken eggs is one of the most common food allergies in children and affects 0.5-9% of the population. The major egg allergens (Gallus spp.): ovomucoid (Gal d 1), ovalbumin (Gal d 2), conalbumin (Gal d 3) and lysozyme (Gal d 4) are present in egg white and most often cause allergic reactions in children. Minor allergens: serum albumin (Gal d 5) and YGP42 protein (Gal d 6) are found in the egg yolk and are more likely to sensitize adults.