Frequency of allergic reactions in egg allergic patients after receiving the yellow fever vaccine.

BACKGROUND: Immunization with live attenuated viral yellow fever vaccine (YFV) grants effective immunity in most cases, and is recommended and prioritized for residents and travelers of endemic countries. YFV is seldom administered to egg-allergic patients (EAP) since it is cultivated in embryonated chicken eggs and may contain residual egg proteins, being a problem for egg-allergic residents and travelers of endemic countries. OBJECTIVE: Describe the frequency of allergic reactions after YFV administration in confirmed EAP from an allergy outpatient center in Bogotá, Colombia. METHODS: An observational, retrospective, cross-sectional, and descriptive study was conducted from January 2017 to December 2019. EAP whose allergy was confirmed with a positive Skin Prick Test (SPT) and/or egg protein-specific IgE levels who hadn't received the YFV were included. Every patient had an SPT, severe EAP, and an additional Intradermal Test (IDT) done with the vaccine. If the vaccine SPT and IDT were negative, the YFV was administered as a single dose; if either were positive, the YFV was administered in graded doses. Statistical analysis was done in Stata16MP. RESULTS: Seventy one patients were included, 24 (33.8%) of those had a history of egg anaphylaxis. All patients had negative YFV SPTs, and two of the five YVF IDTs were positive. Two patients, with previous egg-anaphylaxis, presented allergic reactions to the vaccine. CONCLUSIONS: YFV did not trigger allergic reactions in EAP without history of egg-anaphylaxis. With further research, safe single-dose vaccination to this population could be considered; however, patients with previous egg-anaphylaxis should be evaluated by an allergist before vaccination.

Randomized controlled trial of early regular egg intake to prevent egg allergy.

BACKGROUND: The ideal age to introduce egg into the infant diet has been debated for the past 2 decades in the context of rising rates of egg allergy. OBJECTIVE: We sought to determine whether regular consumption of egg protein from age 4 to 6 months reduces the risk of IgE-mediated egg allergy in infants with hereditary risk, but without eczema. METHODS: Infants aged 4 to 6 months were randomly allocated to receive daily pasteurized raw whole egg powder (n = 407) or a color-matched rice powder (n = 413) to age 10 months. All infants followed an egg-free diet and cooked egg was introduced to both groups at age 10 months. The primary outcome was IgE-mediated egg allergy defined by a positive pasteurized raw egg challenge and egg sensitization at age 12 months. RESULTS: There was no difference between groups in the percentage of infants with IgE-mediated egg allergy (egg 7.0% vs control 10.3%; adjusted relative risk, 0.75; 95% CI, 0.48-1.17; P = .20). A higher proportion of participants in the egg group stopped taking the study powder because of a confirmed allergic reaction (25 of 407 [6.1%] compared with 6 of 413 [1.5%]). Egg-specific IgG4 levels were substantially higher in the egg group at 12 months (median, 1.22 mgA/L vs control 0.07 mgA/L; P < .0001). CONCLUSIONS: We found no evidence that regular egg intake from age 4 to 6 months substantially alters the risk of egg allergy by age 1 year in infants who are at hereditary risk of allergic disease and had no eczema symptoms at study entry.

A randomized trial of egg introduction from 4 months of age in infants at risk for egg allergy.

BACKGROUND: Epidemiologic evidence suggests delayed introduction of egg might not protect against egg allergy in infants at risk of allergic disease. OBJECTIVE: We sought to assess whether dietary introduction of egg between 4 and 6 months in infants at risk of allergy would reduce sensitization to egg. METHODS: We conducted a randomized controlled trial in infants with at least 1 first-degree relative with allergic disease. Infants with a skin prick test (SPT) response to egg white (EW) of less than 2 mm were randomized at age 4 months to receive whole-egg powder or placebo (rice powder) until 8 months of age, with all other dietary egg excluded. Diets were liberalized at 8 months in both groups. The primary outcome was an EW SPT response of 3 mm or greater at age 12 months. RESULTS: Three hundred nineteen infants were randomized: 165 to egg and 154 to placebo. Fourteen infants reacted to egg within 1 week of introduction (despite an EW SPT response <2 mm at entry) and were unsuitable for intervention. Two hundred fifty-four (83%) infants were assessed at 12 months of age. Loss to follow-up was similar between groups. Sensitization to EW at 12 months was 20% and 11% in infants randomized to placebo and egg, respectively (odds ratio, 0.46; 95% CI, 0.22-0.95; P = .03, χ2 test). The absolute risk reduction was 9.8% (95% CI, 8.2% to 18.9%), with a number needed to treat of 11 (95% CI, 6-122). Levels of IgG4 to egg proteins and IgG4/IgE ratios were higher in those randomized to egg (P < .0001 for each) at 12 months. There was no effect on the proportion of children with probable egg allergy (placebo, 13; egg, 8). CONCLUSIONS: Introduction of whole-egg powder into the diets of high-risk infants reduced sensitization to EW and induced egg-specific IgG4 levels. However, 8.5% of infants randomized to egg were not amenable to this primary prevention.

Randomized placebo-controlled trial of hen's egg consumption for primary prevention in infants.

BACKGROUND: Hen's egg is the most common cause of food allergy in early childhood. OBJECTIVE: We investigated the efficacy and safety of early hen's egg introduction at age 4 to 6 months to prevent hen's egg allergy in the general population. METHODS: This randomized, placebo-controlled trial included 4- to 6-month-old infants who were not sensitized against hen's egg, as determined based on specific serum antibodies (IgE). These infants were randomized to receive either verum (egg white powder) or placebo (rice powder) added to the first weaning food 3 times a week under a concurrent egg-free diet from age 4 to 6 until 12 months. The primary outcome was sensitization to hen's egg (increased specific serum IgE levels) by age 12 months. Hen's egg allergy (secondary outcome) was confirmed by double-blind, placebo-controlled food challenges. RESULTS: Among 406 screened infants, 23 (5.7%) had hen's egg-specific IgE before randomization. Seventeen of 23 underwent subsequent double-blind, placebo-controlled food challenges, and 16 were confirmed as allergic, including 11 with anaphylactic reactions. Of the 383 nonsensitized infants (56.7% male), 184 were randomized to verum and 199 to placebo. At 12 months of age, 5.6% of the children in the verum group were hen's egg sensitized versus 2.6% in the placebo group (primary outcome; relative risk, 2.20; 95% CI, 0.68-7.14; P = .24), and 2.1% were confirmed to have hen's egg allergy versus 0.6% in the placebo group (relative risk, 3.30; 95% CI, 0.35-31.32; P = .35). CONCLUSION: We found no evidence that consumption of hen's egg starting at 4 to 6 months of age prevents hen's egg sensitization or allergy. In contrast, it might result in frequent allergic reactions in the community considering that many 4- to 6-month-old infants were already allergic to hen's egg.

Validation of Recipes for Double-Blind Placebo-Controlled Challenges With Milk, Egg White, and Hazelnut.

BACKGROUND: The double-blind, placebo-controlled food challenge (DBPCFC) is considered the definitive diagnostic test for food allergy. Nevertheless, validated recipes for masking the foods are scarce, have not been standardized, and differ between centers. Sensory evaluation techniques such as the triangle test are necessary to validate the recipes used for DBPCFC. METHODS: We developed 3 recipes for use in DBPCFC with milk, egg white, and hazelnut and used the triangle test to validate them in a 2-phase study in which 197 volunteers participated. In each phase, participants tried 3 samples (2 active-1 placebo or 2 placebo-1 active) and had to identify the odd one. In phase 1, the 3 samples were given simultaneously, whereas in phase 2, the 3 samples of foods that failed validation in phase 1 were given sequentially. A visual analog scale (VAS) ranging from 1 to 10 was used to evaluate how much participants liked the recipes. RESULTS: In phase 1, the egg white recipe was validated (n=89 volunteers, 38.9% found the odd sample, P=.16). Milk and hazelnut recipes were validated in phase 2 (for both foods, n=30 participants, 36.7% found the odd sample, P=.36). Median VAS scores for the 3 recipes ranged from 6.6 to 9.7. CONCLUSIONS: We used sensory testing to validate milk, egg white, and hazelnut recipes for use in DBPCFC. The validated recipes are easy to prepare in a clinical setting, provide the equivalent of 1 serving dose, and were liked by most participants.

Short- and long-term antihypertensive effect of egg protein-derived peptide QIGLF.

BACKGROUND: The present study aimed to investigate the in vivo antihypertensive effect on spontaneously hypertensive rats (SHRs) induced by egg protein-derived peptide QIGLF, which has been previously characterized in vitro as a potent angiotensin-converting enzyme inhibitor. RESULTS: In vivo antihypertensive effect of QIGLF orally administered was evaluated by the tail-cuff method. The systolic blood pressure and the diastolic blood pressure of rats were measured 0, 5, 10, 15 and 20 h after administration every day. Subsequently, the effect of QIGLF on angiotensin-converting enzyme mRNA expression in the kidney of SHRs was evaluated by a polymerase chain reaction. Systolic blood pressure was found to be reduced markedly in the SHRs after a single oral administration. CONCLUSION: The results show that the effect of QIGLF (50 mg kg-1 body weight) was similar to that of captopril (10 mg kg-1 body weight) with respect to lowering systolic blood pressure in SHRs. Therefore, egg white protein-derived peptide QIGLF may be useful in the prevention or treatment of hypertension. © 2016 Society of Chemical Industry.

Hydrolysed egg displays strong decrease in allergenicity and is well tolerated by egg-allergic patients.

Food allergies are believed to be on the rise, and currently, management relies on the avoidance of the food. Hen's egg allergy is after cow's milk allergy the most common food allergy; eggs are used in many food products and thus difficult to avoid. A technological process using a combination of enzymatic hydrolysis and heat treatment was designed to produce modified hen's egg with reduced allergenic potential. Biochemical (SDS-PAGE, Size exclusion chromatography and LC-MS/MS) and immunological (ELISA, immunoblot, RBL-assays, animal model) analysis showed a clear decrease in intact proteins as well as a strong decrease of allergenicity. In a clinical study, 22 of the 24 patients with a confirmed egg allergy who underwent a double-blind food challenge with the hydrolysed egg remained completely free of symptoms. Hydrolysed egg products may be beneficial as low-allergenic foods for egg-allergic patients to extent their diet.

An Evaluation of Efficacy and Tolerability of Novel Enzyme Exfoliation Versus Glycolic Acid in Photodamage Treatment.

BACKGROUND: Glycolic acid acts by chemical destruction of adhesions between skin cells to exfoliate superficial skin layers and excess pigmentation. It is well known to improve the appearance of photoaged skin, but is associated with varying degrees of skin irritation. Hydrolyzed salmon roe proteins destroy cell adhesions enzymatically with potentially less irritation than acid treatments. This double-blind prospective study assesses the efficacy and tolerability of hydrolyzed roe versus glycolic acid, and glycolic acid with citric acid. METHODS: 75 female subjects with mild to moderate photodamage, all skin types, and ages 31-70 years, were enrolled. In this 12 week study of twice daily self-treatments, patients were assigned to one of 3 groups; Group 1 (n-19) was assigned hydrolyzed roe cream, Group 2 (n=17), 4% glycolic acid, or Group 3 (n-16), 8% glycolic acid plus 2% citric acid. All patients used the same mild face wash and SPF 30 sunscreen throughout the study. Patients were evaluated at weeks 0, 8 and 12 for objective and subjective tolerability, improvement in photodamage by VISIA Complexion Analysis, modified Packman and Gans method, Visual Analog Scale (VAS), and answered an opinion questionnaire. RESULTS: Group 1 improved in skin clarity from a VAS 44.1 to 55.7 (P=0.0317) at week 12. VISIA mean scores correlated with office evaluation showing improvement in brown spots from 453 to 417 (P = 0.0115) at 12 weeks. Group 2 improved in superficial fine lines at week 8 (-5.9, P=0.0428) and week 12 (-9.1, P=0.0019). Group 3 improved at week 12 in skin clarity (11.5, P = 0.0469) and skin roughness (-13.3, P = 0.0426), and in hyperpigmentation at week 8 (-9.4, P = 0.0462) and week 12 (-14.6, P= 0.0019). CONCLUSION: Topical hydrolyzed roe protein used twice daily improves skin clarity. It has good tolerability with fewer instances of stinging and burning than the other glycolic acid containing creams. Patient's opinions of the 3 products were similar.

Safety of food challenges to extensively heated egg in egg-allergic children: a prospective cohort study.

BACKGROUND: Many children with IgE-mediated allergy to egg can tolerate egg in baked foods. However, the clinical characteristics and severity of reactions of egg-allergic children who react to baked egg at open food challenge (OFC) are not well defined. METHODS: Children presenting to our tertiary referral clinic with a diagnosis of egg allergy and following complete egg avoidance in their diet were offered OFC to baked egg. Challenges were performed with incremental dosages to a total of one baked muffin containing 1/6 egg (equivalent to 1 g egg protein) following a standardized protocol. Data were collected prospectively from 2009-2012. RESULTS: Open food challenge to baked egg were carried out on 236 egg-allergic children who had been strictly avoiding egg in their diet. A total of 150 children (64%) passed and successfully incorporated baked egg into their diet. Eighty-six children (36%) reacted to their challenge. Of these, 12 (14%) experienced anaphylaxis (according to WAO criteria), including four to <100 mg extensively heated egg protein. Intramuscular adrenaline was administered to 5 of the 12 children, one of whom required a second dose due to persistent hypotension. Skin prick testing, asthma, or prior egg anaphylaxis were not predictive of challenge outcome. CONCLUSION: The majority of children with IgE-mediated allergy to egg were able to tolerate 1 g of baked egg protein, but the outcome of OFC remained unpredictable, and 14% of children who failed OFC reacted with anaphylaxis. We recommend that OFC to baked egg should take place under medical supervision.

Oral food desensitization in children with IgE-mediated hen's egg allergy: a new protocol with raw hen's egg.

BACKGROUND: Hen's egg allergy affects young children and can cause severe allergic reactions. Avoidance results in dietary limitations and can affect the quality of life, especially in cases where potentially life-threatening reactions exist. Our objective was to desensitize children with moderate-severe IgE-mediated hen's egg allergy over a 6-month period, by introducing increasing and very gradual daily doses of raw hen's egg in order to enable the children to assume 25ml of this food, or to induce tolerance to the highest possible dose. The protocol foresaw the egg reintroduction in the home setting. METHODS: In this randomized, controlled open study, 20 hen's egg allergic children (10 in the active group) were admitted. A convincing history or a positive double-blind placebo-controlled food challenge confirmed the diagnosis. Oral desensitization was performed with increasing doses starting from 0.27 mg of hen's egg proteins (1 drop of raw hen's egg diluted 1:100). We adopted an original, mathematically calculated protocol in order to ensure a constant, daily increment of doses. RESULTS: 8/10 children (80%) in the active group achieved the daily intake of 25ml over a 6-month period. One child (10%) could tolerate up to 2ml/day while another child (10%) failed the desensitization. Six months after enrolment only 2 children in the control group (20%) could tolerate hen's egg. CONCLUSIONS: We successfully desensitized 8/10 children with IgE-mediated hen's egg allergy in a 6-month period. The partial outcome in the child who could tolerate 2ml/day reduced the risk of severe reactions after unnoticed introduction of egg. A regular protocol that ensures a daily constant increase of doses helps to reduce possible adverse events, thus improving safety and effectiveness.

Relating microarray component testing and reported food allergy and food-triggered atopic dermatitis: a real-world analysis.

BACKGROUND: High epitope diversity has been associated with increased IgE-mediated food allergy severity. OBJECTIVE: To characterize associations between results from an automated microarray system and self-reported food allergy and food-triggered atopic dermatitis (AD). METHODS: Families with food allergic children were identified from a Jewish community in Lakewood, New Jersey, with immediate family members without food allergy or food-triggered AD serving as controls for the identified children. Sets of microarray components analyzed were to milk (Bos d 4, Bos d 5, Bos d 8, Bos d lactoferrin), egg (Gal d 1, Gal d 2, Gal d 3, Gal d 5), and peanut (Ara h 1, Ara h 2, Ara h 3, Ara h 6). RESULTS: Seventy-three patients from 23 families were recruited. Culprit foods included milk (n = 20), egg (n = 10), and peanut (n = 6) for food allergy and milk (n = 10) and egg (n = 7) for food-triggered AD. Odds of having had a self-reported related food allergy or food-triggered AD reaction significantly increased with a higher number of detectable microarray components to that food. Ara h 1, Ara h 2, and Ara h 6 were individually associated with reported peanut allergy, and Bos d 4 was individually associated with reported milk allergy. The number of egg components significantly increased the odds of having related food-triggered AD. CONCLUSION: High diversity of food allergen components relates well to self-reported history of food allergy and food-associated AD.

The antioxidant effects of soybean lecithin- or low-density lipoprotein-based extenders for the cryopreservation of brown-bear (Ursus arctos) spermatozoa.

Egg yolk low-density lipoproteins (LDL) and soybean lecithin were evaluated as replacements for egg yolk in extenders used for the cryopreservation of brown-bear spermatozoa. The motility, viability and acrosomal status of post-thawed spermatozoa were analysed, and an egg-yolk extender was used as a control. The total antioxidant capacity of these extenders was tested. Soybean lecithin showed an effect that was dependent on the soybean concentration (2%, 3.5% and 5%) and source (Type A: 24% L-α-phosphatidylcholine, and Type B: 14-23% L-α-phosphatidylcholine). Only semen cryopreserved with 5% Type A soybean exhibited a sperm motility similar to that of semen cryopreserved in egg-yolk-based extender after thawing, although the sperm viability and acrosome status were not as high. Semen frozen in an extender containing LDL (10-15%) exhibited improved sperm viability in comparison with the control, but sperm motility was lower. The LDL-based extender exhibited a higher anti-oxidant activity than the egg-yolk extender and soy lecithin-based extenders. The extenders with higher anti-oxidant activity showed improvements in frozen sperm viability but lower semen motility. These results indicate that soybean lecithin did not have the same protective effect as egg yolk during the freezing of brown-bear spermatozoa but suggest that LDL (10-15%) could be a useful substitute for egg yolk in these extenders.

Immunology in the Clinic Review Series; focus on allergies: immunotherapy for food allergy.

There is no approved therapy for food allergy. The current standard of care is elimination of the triggering food from the diet and accessibility to epinephrine. Immunotherapy is a promising treatment approach. While desensitization to most foods seems feasible, it remains unclear if a permanent state of tolerance is achievable. The research team at Duke is pioneering immunotherapy for food allergies. Work here has evolved over time from small open-label pilot studies to larger randomized designs. Our data show that immunological changes associated with immunotherapy include reduction in mast cell reactivity, decreased basophil responses, decreased specific-immunoglobulin (Ig)E, increased IgG4 and induction of regulatory T cells. Immunotherapy has generated much excitement in the food allergy community; however, further studies are needed before it is ready for clinical use.

Anaphylactic reaction to probiotics. Cow's milk and hen's egg allergens in probiotic compounds.

BACKGROUND: Probiotics are used in the treatment of allergic diseases. We investigated the safety of probiotics for subjects with food allergy. MATERIAL AND METHODS: Labels of probiotics commercially available in Spain were examined to assess their content of cow's milk or hen's egg. Skin prick tests with these compounds (20 mg/ml) were performed in five children allergic to cow's milk, five children allergic to hen's white egg, and five control subjects non-allergic to food. Three serum pools: I (positive-specific IgE to cow's milk and hen's egg white proteins), II (positive-specific IgE to cow's milk and negative to hen's egg white proteins), and III (negative-specific IgE to cow's milk and positive to hen's egg white proteins) were used to detect cow's milk and hen's egg white allergens in probiotics. ImmunoCAP(®) (Phadia), in-house ELISA, SDS-PAGE immunoblotting, and inhibition studies of these assays were performed. Proteins were quantified by enzyme-immunoassay. RESULTS: Eleven probiotics were studied. No label advertised about egg content, eight labels warned about lactose, lactic acid or cow's milk, one label claimed to be milk-free, and two gave no information. Cow's milk proteins were detected, by at least one lab technique, in 10/11 probiotics, three over 2.5 mg/kg (21, 52, 112 mg/kg). Hen's egg white proteins were detected in 3/11 probiotics, only one had more than 2.5 mg/kg (47 mg/kg). CONCLUSION: Probiotic compounds may contain hidden allergens of food and may not be safe for subjects with allergy to cow's milk or hen's egg.

An update on influenza vaccination in patients with egg allergy.

PURPOSE OF REVIEW: Egg allergy is a common problem affecting young children especially. There has been much debate over the past several decades on how to approach the subject of influenza vaccination in children with egg allergy. RECENT FINDINGS: Because of concern regarding the egg protein content in the influenza virus vaccine, pediatricians have in the past typically taken a conservative approach of avoiding influenza vaccination in egg-allergic patients. Subsequently, it was shown that the influenza vaccine could be safely administered to patients who had negative skin testing to the vaccine. Most recently, studies have demonstrated a low risk of giving the vaccine either in divided doses or as a single dose in a controlled setting without the need for skin testing. SUMMARY: In considering vaccination in a patient with a history of egg allergy, several factors should be weighed, including the severity of the egg allergy, the egg content of vaccines, and the setting of vaccine administration. However, it appears that the risk of anaphylaxis to the influenza vaccine in patients with egg allergy may be much lower than previously thought, suggesting that in many cases skin testing may not be necessary.

SIT beyond respiratory diseases.

OBJECTIVE: The goal was to assess the effectiveness of specific immunotherapy (SIT) in reduction of symptoms and medication score in patients with immunoglobulin E (IgE) mediated extrinsic form of atopic dermatitis (AD); and to assess the effectiveness of oral immunotherapy (OIT) as "active" treatment to achieving tolerance for food(s) in patients with IgE mediated food allergy. DATA SOURCES: Computerized bibliographic searches of MEDLINE (1998-2010) were supplemented by hand searches of reference lists. Studies were included if they were double-blind randomized controlled trials comparing subcutaneous immunotherapy (SCIT) or sublingual immunotherapy (SLIT) or OIT with placebo. However uncontrolled studies and case reports were also included. STUDY SELECTIONS: Thirty-two studies were analyzed. Because of the high heterogeneity of the AD studied only results of 2 placebo controlled studies 1-SCIT and 1-SLIT respectively were comparable. Among OIT studies: 4 carried out with control groups were analyzed. RESULTS: From 36% to 92% of patients treated with OIT reached tolerance to cow's milk or egg; a rate of 8% to 53% reached partial tolerance. The patients had either clinical history of severe systemic reactions to foods: anaphylaxis, or mild to moderate reactions. Regarding SIT for AD: 72% of patients treated with house dust mite SCIT and 54% treated with SLIT had a significant improvement of SCORAD-Index. CONCLUSIONS: This review found that OIT with cow's milk or egg is effective in achieving full tolerance or partial tolerance in the majority of patients with IgE mediated food allergy. SIT may represent an additional therapeutic tool for the treatment of extrinsic AD in properly selected patients.

Hen egg hair mask-induced food allergy: a case report.

We report the case of a 46-year-old woman who treated her hair with a homemade egg-white based mask. After one year of weekly applications, the ingestion of egg triggered rhinitis, choking and systemic urticaria. Though the breakdown of oral tolerance to egg has been reported elsewhere in the literature, to the best of our knowledge, this is the first case of hair mask-induced allergy.

Integrative Transcriptomics Reveals Activation of Innate Immune Responses and Inhibition of Inflammation During Oral Immunotherapy for Egg Allergy in Children.

We previously reported the results of a randomized, open-label trial of egg oral immunotherapy (OIT) in 50 children where 44% were desensitized and 46% were partially desensitized after 8 months of treatment. Here we focus on cell-mediated molecular mechanisms driving desensitization during egg OIT. We sought to determine whether changes in genome-wide gene expression in blood cells during egg OIT correlate with humoral responses and the clinical outcome. The blood cell transcriptome of 50 children receiving egg OIT was profiled using peripheral blood mononuclear cell (PBMC) samples obtained at baseline and after 3 and 8 months of OIT. We identified 467 differentially expressed genes (DEGs) after 3 or 8 months of egg OIT. At 8 months, 86% of the DEGs were downregulated and played a role in the signaling of TREM1, IL-6, and IL-17. In correlation analyses, Gal d 1-4-specific IgG4 antibodies associated positively with DEGs playing a role in pathogen recognition and antigen presentation and negatively with DEGs playing a role in the signaling of IL-10, IL-6, and IL-17. Desensitized and partially desensitized patients had differences in their antibody responses, and although most of the transcriptomic changes were shared, both groups had also specific patterns, which suggest slower changes in partially desensitized and activation of NK cells in the desensitized group. OIT for egg allergy in children inhibits inflammation and activates innate immune responses regardless of the clinical outcome at 8 months. Changes in gene expression patterns first appear as posttranslational protein modifications, followed by more sustained epigenetic gene regulatory functions related to successful desensitization.

A convenient and sensitive allergy test: IgE crosslinking-induced luciferase expression in cultured mast cells.

BACKGROUND: For the detection of allergen-specific IgE in sera, solid-phase IgE-binding assays like the CAP test are commonly used. Although such immunochemical methods are very sensitive, they frequently produce false positives. Degranulation of the human IgE receptor (FcεRI)-transfected rat mast cell (RBL) lines seems to be a possible indicator for human IgE, but spontaneous mediator release from these cells in the presence of human sera is not negligible. METHODS: The nuclear factor of activated T-cells (NFAT)-responsive luciferase reporter gene was stably transfected into human FcεRI-expressing RBL-SX38 cells. One established clone (RS-ATL8) was sensitized with 1 : 100 dilution of sera from patients with egg white allergy and then stimulated with purified or a crude extract of egg white allergen. RESULTS: Sensitization with 15 pg/ml IgE was sufficient to detect IgE crosslinking-induced luciferase expression (EXiLE) by anti-IgE stimulation. Allergen-specific EXiLE was elicited by as little as 1 fg/ml of egg white protein without cytotoxicity. There was a good correlation between results with EXiLE and oral food challenge tests on patients with egg allergy (P = 0.001687, Fisher's exact test). The measured values of EXiLE and the CAP test also correlated well (R = 0.9127, Spearman's test). CONCLUSION: The EXiLE test using RS-ATL8 cells is a promising in vitro IgE test to evaluate the biological activity of the binding between IgE and allergens.

Correlation of allergen-specific IgG subclass antibodies and T lymphocyte cytokine responses in children with multiple food allergies.

Cytokines can affect the quantity and class of allergen-specific immunoglobulins through the T cell polarization that accompanies atopy. Antigen-specific IgG subclasses and IgE antibodies were compared with intracellular T cell cytokine changes to sensitizing antigens in 23 children with multiple food allergies and 20 healthy controls. Allergic children showed higher levels of total and food-specific IgE, IgG1 and IgG4 to peanut, milk and egg than non-atopic children or adults, coinciding with a TH2 cytokine response to sensitizing antigens. IgG1 and IgG4 antibodies specific to milk and egg and peanut protein were elevated relative to age-matched healthy children (p