Anubha Tripathi

Galactose-α-1,3-galactose and Delayed Anaphylaxis, Angioedema, and Urticaria in Children

BACKGROUND AND OBJECTIVE: Despite a thorough history and comprehensive testing, many children who present with recurrent symptoms consistent with allergic reactions elude diagnosis. Recent research has identified a novel cause for “idiopathic” allergic reactions; immunoglobulin E (IgE) antibody specific for the carbohydrate galactose-α-1,3-galactose (α-Gal) has been associated with delayed urticaria and anaphylaxis that occurs 3 to 6 hours after eating beef, pork, or lamb. We sought to determine whether IgE antibody to α-Gal was present in sera of pediatric patients who reported idiopathic anaphylaxis or urticaria. METHODS: Patients aged 4 to 17 were enrolled in an institutional review board–approved protocol at the University of Virginia and private practice allergy offices in Lynchburg, VA. Sera was obtained and analyzed by ImmunoCAP for total IgE and specific IgE to α-Gal, beef, pork, cat epithelium and dander, Fel d 1, dog dander, and milk. RESULTS: Forty-five pediatric patients were identified who had both clinical histories supporting delayed anaphylaxis or urticaria to mammalian meat and IgE antibody specific for α-Gal. In addition, most of these cases had a history of tick bites within the past year, which itched and persisted. CONCLUSIONS: A novel form of anaphylaxis and urticaria that occurs 3 to 6 hours after eating mammalian meat is not uncommon among children in our area. Identification of these cases may not be straightforward and diagnosis is best confirmed by specific testing, which should certainly be considered for children living in the area where the Lone Star tick is common.

Anaphylaxis to the Carbohydrate Side Chain Alpha-gal

In 2007, the monoclonal antibody cetuximab caused severe hypersensitivity reactions during the first infusion in a region of the southeastern United States. Investigation of pretreatment sera established that they contained immunoglobulin (Ig) E against the oligosaccharide galactose-alpha-1,3-galactose (alpha-gal), which is present on the Fab of cetuximab. Alpha-gal is a blood group substance of nonprimate mammals. These IgE antibodies are also associated with delayed anaphylaxis to red meat (ie, to meat or organs of animals that carry this oligosaccharide). Evidence shows that the primary cause of these IgE antibodies is bites from the tick Amblyomma americanum or its larvae.

IgE Antibody Detection and Component Analysis in Patients with Eosinophilic Esophagitis

BACKGROUND Although IgE antibodies to cows milk and wheat are common in patients with eosinophilic esophagitis (EoE), titers are low and responses to diet are not dependent on having IgE antibodies. OBJECTIVE To better define specific IgE antibody responses to foods, focusing on those foods that appear to play a role in EoE. METHODS Adult (n = 46) and pediatric (n = 51) patients with EoE were recruited for skin prick testing and serum measurement (whole and diluted) of IgE antibodies specific for aeroallergens, food extracts, and component allergens by ImmunoCAP. Immuno Solid-phase Allergen Chip analysis was also used to measure the specificity of IgE antibodies to 112 allergen molecules. RESULTS In adults and children, there was a higher prevalence of sensitization to food extracts by ImmunoCAP than by skin prick testing. Using Immuno Solid-phase Allergen Chip to assess the specificity of IgE antibodies to 112 allergen molecules, we found that results for food allergens were mostly negative. In contrast, ImmunoCAP assays for specific milk allergens gave positive IgE antibody results in 31 of 34 sera. The correlations between specific IgE antibody to Bos d 4 or Bos d 5 and milk extract were strong (R = 0.89 and 0.76, respectively; P < .001). The evidence that IgE antibodies to foods were directed at minor components of the extracts was further supported by measurements on diluted sera. CONCLUSIONS The IgE responses in cows milk-sensitized patients with EoE are frequently to whey proteins Bos d 4 and Bos d 5, minor components of the extract. These IgE assays may be able to identify the proteins that are relevant to EoE even though IgE is not the primary mechanism.

Delayed anaphylaxis to red meat masquerading as idiopathic anaphylaxis.

Anaphylaxis is traditionally recognized as a rapidly developing combination of symptoms that often includes hives and hypotension or respiratory symptoms. Furthermore, when a specific cause is identified, exposure to this cause is usually noted to have occurred within minutes to 2 hours before the onset of symptoms. This case is of a 79-year-old woman who developed a severe episode of anaphylaxis 3 hours after eating pork. Before 2012, she had not experienced any symptoms after ingestion of meat products. Delayed anaphylaxis to mammalian meat has many contrasting features to immediate food-induced anaphylaxis. The relevant IgE antibody is specific for the oligosaccharide galactose-alpha-1,3-galactose, a blood group substance of nonprimate mammals. There is evidence from Australia, Sweden, and the United States that the primary cause of this IgE antibody response is tick bites. These bites characteristically itch for 10 days or more. Diagnosis can be made by the presence of specific IgE to beef, pork, lamb, and milk, and the lack of IgE to chicken, turkey, and fish. Skin prick tests (but not intradermal tests) generally are negative. Management of these cases, now common across the southeastern United States, consists of education combined with avoidance of both ingestion of red meat and further tick bites.

Porcine or bovine valve replacement in 3 patients with IgE antibodies to the mammalian oligosaccharide galactose-alpha-1,3-galactose

Patients who develop IgE to the oligosaccharide galactose-alpha1,3-galactose (alpha-gal) report delayed allergic reactions after eating beef, pork, or lamb. To date, there have been no published reports that indicate whether IgE to alpha-gal is associated with a risk of anaphylaxis at the time of engraftment of a bovine or porcine valve. This case series documents the clinical courses of 3 patients with elevated IgE to alpha-gal who required porcine or bovine valve replacement. Two patients experienced perioperative or postoperative hypersensitivity reactions, but all 3 were tolerating valve replacement.

Specific IgG4 Antibodies to Cow’s Milk Proteins in Pediatric Eosinophilic Esophagitis

Background: Allergen‐specific IgG4 (sIgG4) antibodies are often associated with tolerance, but sIgG4 antibodies to causally relevant foods have been reported recently in adults with eosinophilic esophagitis (EoE). Prevalence and levels of food sIgG4 are not well established in the general pediatric population. Objective: We sought to investigate serum food sIgG4 with component diagnostics in children with EoE and children from an unselected birth cohort and to explore the effects of sex, age, and milk consumption on sIgG4 levels. Methods: Sera from 71 pediatric patients with EoE and 210 early adolescent children from an unselected birth cohort (Project Viva) were assayed for sIgG4 and specific IgE (sIgE) to major cows milk (CM) proteins (&agr;‐lactalbumin, &bgr;‐lactoglobulin, and caseins) and to wheat, soy, egg, and peanut proteins. Results: In the EoE cohort high‐titer sIgG4 (≥10 &mgr;g/mL) to CM proteins was more common than in control sera and achieved odds ratios for EoE ranging from 5.5 to 8.4. sIgE levels to CM proteins were mostly 4 IU/mL or less in patients with EoE, such that sIgG4/sIgE ratios were often 10,000 or greater. When adjusted for age and milk consumption, high‐titer sIgG4 to CM proteins was strongly associated with EoE, with an odds ratio of greater than 20 to all 3 CM proteins in boys. Conclusions: sIgG4 to CM proteins are common and high titer in children with EoE. Although it is not clear that this response is pathogenic, sIgG4 levels imply that these antibodies are an important feature of the local immune response that gives rise to EoE. GRAPHICAL ABSTRACT Figure. No caption available.

Underestimation of specific IgE measurements using extract-based assays on undiluted sera revealed through dilution

The measurement of specific IgE (sIgE) to foods is an established clinical tool for the diagnosis and management of allergic disease. Normally, sIgE is measured using undiluted serum, and assays are only performed at a dilution if the value is greater than or equal to 90 international units (IU)/mL. Thus, when serum gives sIgE values of less than or equal to 50 IU/mL, the possibility that the value is a significant underestimate is rarely considered. The underestimation of results using undiluted serum is a well-known limitation of immunoprecipitation, immunodiffusion, and nephelometry, where it is referred to as a “prozone” or “hook” effect. However, there is very little awareness of this phenomenon in the measurement of sIgE. We sought to investigate this phenomenon using sera collected from patients with the a-gal syndrome (AS) (n 1⁄4 3), which involves delayed reactions to mammalian products (red meat or dairy) related to sIgE to galactose-a-1,3-galactose (a-gal). We addressed additional allergens using sera from subjects with eosinophilic esophagitis (EoE) (n 1⁄4 17), peanut allergy (n 1⁄4 4), or oral allergy syndrome (n 1⁄4 5). Serum was collected from patients at the University of Virginia (Charlottesville, Va) or Ohio State University/Nationwide Children’s Hospital (Columbus, Ohio) clinics. We measured sIgE to beef, milk, mite (Dermatophagoides pteronyssinus), cat dander, cow’s milk, and peanut extracts by ImmunoCAP in progressively diluted sera. The results were expressed in fluorescent response units (FRU) or IU/mL (positive, 0.35 IU/mL). In addition, sIgE to purified allergens was measured by ImmunoCAP (a-gal, Bos d 4, Bos d 5, Bos d 6, Bos d 8, Ara h 1, Ara h 2, and/or Ara h 8) or Immuno Solid-Phase Allergen Chip (Der p 1, Der p 2, Der p 10, Fel d 1, and/or Fel d 4) to determine the patients’ dominant sensitization(s). Methods for sIgE to a-gal, Immuno Solid-Phase Allergen Chip, and IgG4 assays are detailed in this article’s Online Repository at www.jaci-inpractice.org. In brief, the a-gal sIgE assay uses 20 mg cetuximab coupled to the solid phase. The result in Figure 1, A, demonstrates that there is a substantial dilution effect when assaying sIgE to beef and milk extract in sera from a subject with AS. Of note, a-gal constitutes a minor fraction of the antigens in beef and milk. To further examine this phenomena, we performed dilution studies using ImmunoCAP for beef extract or a-gal on sera from 3 patients with AS who had highly positive sIgE to a-gal (>100 IU/mL). These values for sIgE to a-gal allowed us to dilute the sera past 1:1000 before sIgE levels were undetectable. We compared curves for sIgE to beef extract and a-gal to a control curve, which revealed dramatic differences (Figure 1, B and C). Focusing on sIgE to beef extract in AS #1, the FRU in the undiluted serum were approximately the same as the value for the 1:4 dilution, which illustrated a “hook” effect (Figure 1, C). In another patient with AS who was highly positive for sIgE to a-gal (>100 IU/mL), we recreated the situation of insufficient antigen using progressively diluted serum and low cetuximab (800 ng) on the solid phase (see Figure E1 in this article’s Online Repository at www.jaci-inpractice.org). The dilution curve deviated from the control curve and that of the standard cetuximab immunoCAP, indicating that the amount of antigen on the solid phase was insufficient for accurate measurement of sIgE to a-gal. We also applied decreasing quantities of cetuximab to the solid phase and measured sIgE to a-gal using undiluted serum from a patient with AS (see Figure E2 in this article’s Online Repository at www.jaci-inpractice.org) and the resultant curve showed a dose-response relationship between the mass of cetuximab on the solid phase and the assay readout. Thus, manipulating the amount of allergen on the solid phase, such that there is an imbalance in antibody and allergen concentrations, can markedly change the measured sIgE values. Next, we performed dilution studies using sIgE assays for mite (n 1⁄4 6), cat dander (n 1⁄4 4), and cow’s milk (n 1⁄4 11) extracts in selected IgE-positive sera from 17 patients with EoE and also for peanut extract in the sera from patients with peanut allergy and oral allergy syndrome. Mite, cat dander, cow’s milk, and peanut extracts consist of many different allergens, which are present in unequal amounts on the solid phase (see Table E1 in this article’s Online Repository at www.jaci-inpractice.org). In cases in which Der p 2, Fel d 1, Bos d 8, or Ara h 2 were the primary allergen targets, dilution had little effect on the results; each of these allergens represents a significant or large proportion of the respective extracts (Figure 1, D). In contrast, there was a pronounced dilution effect in many of the sera from subjects dominantly sensitized to Bos d 4 and Ara h 8, which are quantitatively a minor fraction of the relevant extract (Figure 1, D; Table E1). We then determined the percentage difference in sIgE values in the undiluted and 1:8 (calculated) samples from each assay (Table I). There was a strong negative correlation (rs 1⁄4 0.79; 95% CI, 0.90 to 0.61; P < .001) between the representation of the dominant allergen for each patient and the percentage difference between the undiluted and 1:8 measurements (Figure 1, E; see Table E2 in this article’s Online Repository at www.jaci-inpractice.org). There are 2 major effects related to the use of undiluted serum in sIgE assays that can cause false negatives or that can underestimate measurements. Both effects essentially occur because of

Proceedings of the 2015 WAO Symposium on Food Allergy and the Microbiome

Table of contentsA1 Characterization of the immunoallergic profile towards the proteins of the wheat flour in Cuban populationRaúl Lázaro Castro Almarales, Mary Carmen Reyes Zamora, Beatriz Tamargo, Damaris Torralba Averoff, Raysa Cruz, Yunia Oliva Diaz, Mirta Alvarez Castello, Alexander Ciria, Alexis Labrada, Maytee MateoA2 Are peanuts causing food allergy in Cuba?Maytee Mateo, Damaris Torralba Averoff, Raysa Cruz, Yunia Oliva Diaz, Mirta Alvarez Castello, Alexander Ciria, Mary Carmen Reyes Zamora, Beatriz Tamargo, Alexis LabradaA3 Prick test and immunoallergic profile to soy allergens in Cuban populationOmar Herrera, Maytee Mateo, Raysa Cruz, Mirta Alvarez Castello, Alexander Ciria, Raúl Lázaro Castro Almarales, Mary Carmen Reyes Zamora, Alexis LabradaA4 Skin sensitization and immunoallergic profile to hens egg in Cuban populationJosé Severino Rodríguez Canosa, Raysa Cruz, Maytee Mateo, Mirta Alvarez Castello, Alexander Ciria, Raúl Lázaro Castro Almarales, Mary Carmen Reyes Zamora, Alexis LabradaA5 Sensitization to three domestic mites in patients with adverse food events to shellfishMirta Alvarez Castello, Raúl Lázaro Castro Almarales, Alexis Labrada, BiocenA6 Diagnostic efficacy by skin prick test with allergenic extracts of legumes in Cuban patientsYamilet Ibizate Novales, Ilonka Estruch Fajardo, Alexis Labrada, Maytee Mateo, Armando GinardA7 Baked egg goods without wheat flour carry an increased risk of reactionBruce Lanser, Anna Faino, Erwin Gelfand, Pia HaukA8 Prevalence, incidence and associated risk factors of adverse reaction to food in Cuban infants - a population-based prospective studySilvia Venero Fernández, Julia Urbina, Mirta Alvarez Castello, Raúl Lázaro Castro Almarales, Ramón Suárez Medina, Hermes Fundora Hernández, John Britton, Andrew William FogartyA9 Microbiome in ice machines and assessing the plasma nanotechnology in breaking the biofilm and improving air qualityNabarun Ghosh, Clinton Ross Bell, Chandini Revanna, Constantine Saadeh, Jeff Bennert, Danius Bouyi, Mitsy Veloz, Nelofar SheraliA10 Characteristics of patients with food allergy in health public serviceMagna CoelhoA11 Allergic rhinitis and asthma index increased in Texas panhandle and AHPCO and plasma nanotechnology as solutionsNabarun Ghosh, Jeff Bennert, Danius Bouyi, Constantine Saadeh, Clinton Ross Bell, Mitsy Veloz, Chandini Revanna, Nelofar SheraliA12 Antigen-specific T follicular helper cells mediate peanut allergy in miceJoseph J. Dolence, Takao Kobayashi, Koji Iijima, Hirohito Kita, Hirohito Kita, Ashli Moore, James KrempskiA13 Production of recombinant Mal d 3, a major apple allergen, in Pichia Pastoris, to investigate the impact of the food matrix and post-translational modifications on Mal d 3 immuno-reactivityRoberta Aina, Riccardo Asero, Sabine Pfeifer, Pawel Dubiela, Merima Bublin, Christian Radauer, Piotr Humeniuk, Karin Hoffmann-SommergruberA14 Reaction to sports drink: no whey! Whey allergy in absence of clinical cow’s milk allergyFrank Eidelman, Ves Dimov, Charl KhalilA15 Food allergy on Tumblr: focus on teenage audience may increase educational impactVes Dimov, Frank Eidelman, Charl KhalilA16 Changes in IgE levels following one-year immunizations in two children with food allergyAlice E. W. Hoyt, Peter Heymann, Alexander Schuyler, Scott Commins, Thomas Platts-MillsA17 IgE and IgG4 antibodies to cows milk components in children with eosinophilic esophagitis: higher specific IgG4 antibodies and IgG4:IgE ratios compared with subjects with IgE-mediated food allergyAlexander Schuyler, Patrice Kruszewski, John Russo, Lisa Workman, Thomas Platts-Mills, Elizabeth Erwin, Anubha TripathiA18 Frequency of Sensitization to Food Allergens in Patients with Rhinitis and Asthma in the National Medical Center La Raza “Dr. Antonio Fraga Mouret”, Mexico CityGabriela Yvette Castellanos, Elizabeth Mendieta, Martín Becerril-Angeles

Measurement of IgE antibodies to minor components in eosinophilic esophagitis, peanut allergy, and delayed anaphylaxis to mammalian meat

Background In the investigation of food allergy syndromes, serum assays detecting IgE antibodies (Ab) to food allergens use whole extracts on the solid phase, which contain specific allergen components in varying amounts. The interpretation of results assumes that the causative allergen components are adequately represented in the extract and that the presence and level of specific IgE titer to the whole extract of the relevant food(s) are diagnostic of the syndrome. IgE assays for beef or pork can underestimate the IgE Ab to a minor component of mammalian meat, such as galactose-a-1,3-galactose (a-gal). The inciting food allergens in Eosinophilic Esophagitis (EoE) remain unclear, although IgE Ab to milk, wheat, soy, and peanut are frequently present in low titer.

Seventeen-year-old girl hospitalized for localized swelling, pruritus, tenderness, and lymphatic streaking with eosinophilia

A variety of skin disorders are referred to allergists, especially when they are associated with other atopic symptoms and/or blood eosinophilia. Although urticaria and atopic dermatitis are the most common skin manifestations of allergic disease in children and adults, the clinician must maintain a high degree of suspicion with regards to other potential sources of IgE, including biting insects, in a patient with these symptoms.