Alexander J. Schuyler

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.

Allergens, sources, particles, and molecules: Why do we make IgE responses?

Allergens are foreign proteins or glycoproteins that are the target of IgE antibody responses in humans. The relationship between subsequent exposure and the allergic symptoms is often or usually obvious; however, there is increasing evidence that in asthma, atopic dermatitis and some forms of food allergy the induction of symptoms is delayed or chronic. The primary exposure to inhaled allergens is to the particles, which are capable of carrying allergens in the air. Thus, the response reflects not only the properties of the proteins, but also the biological properties of the other constituents of the particle. This is best understood in relation to the mite fecal particles in which the contents include many different immunologically active substances. Allergic disease first became a major problem over 100 years ago, and for many years sensitization to pollens was the dominant form of these diseases. The rise in pediatric asthma correlates best with the move of children indoors, which started in 1960 and was primarily driven by indoor entertainment for children. While the causes of the increase are not simple they include both a major increase in sensitization to indoor allergens and the complex consequences of inactivity. Most recently, there has also been an increase in food allergy. Understanding this has required a reappraisal of the importance of the skin as a route for sensitization. Overall, understanding allergic diseases requires knowing about the sources, the particles and the routes of exposure as well as the properties of the individual allergens.

Galactose-α-1,3-Galactose: Atypical Food Allergen or Model IgE Hypersensitivity?

Purpose of ReviewGalactose-α-1,3-galactose (α-gal) is a carbohydrate allergen with several unique characteristics. In this article, we discuss some recent advances in our understanding of the ‘alpha-gal syndrome,’ highlight data supporting the role of ticks in pathogenesis, and speculate on immune mechanisms that lead to sensitization.Recent FindingsFirst described as the target of IgE in individuals suffering immediate hypersensitivity reactions to the novel anti-EGF monoclonal antibody cetuximab, it is now clear that α-gal sensitization is associated with mammalian meat allergy as well as reactions to other mammalian products. Unlike traditional IgE-mediated food allergies, reactions to α-gal often do not manifest until several hours following an exposure, although co-factors can influence the presentation. Multiple pieces of evidence, including recent work with a mouse model, point to the fact that sensitization is mediated by exposure to certain hard ticks and increasingly we are aware of its globally widespread impact.SummaryThe oligosaccharide α-gal represents a novel allergen with several unusual clinical features. It has been recognized now on multiple continents and its clinical presentation can be quite variable. Moreover, efforts to delineate the mechanisms leading to α-gal sensitization may have ramifications for our broader understanding of type 2 immunity.

TH1 signatures are present in the lower airways of children with severe asthma, regardless of allergic status

Background: The pathogenesis of severe asthma in childhood remains poorly understood. Objective: We sought to construct the immunologic landscape in the airways of children with severe asthma. Methods: Comprehensive analysis of multiple cell types and mediators was performed by using flow cytometry and a multiplex assay with bronchoalveolar lavage (BAL) specimens (n = 68) from 52 highly characterized allergic and nonallergic children (0.5–17 years) with severe treatment‐refractory asthma. Multiple relationships were tested by using linear mixed‐effects modeling. Results: Memory CCR5+ TH1 cells were enriched in BAL fluid versus blood, and pathogenic respiratory viruses and bacteria were readily detected. IFN‐&ggr;+IL‐17+ and IFN‐&ggr;−IL‐17+ subsets constituted secondary TH types, and BAL fluid CD8+ T cells were almost exclusively IFN‐&ggr;+. The TH17‐associated mediators IL‐23 and macrophage inflammatory protein 3&agr;/CCL20 were highly expressed. Despite low TH2 numbers, TH2 cytokines were detected, and TH2 skewing correlated with total IgE levels. Type 2 innate lymphoid cells and basophils were scarce in BAL fluid. Levels of IL‐5, IL‐33, and IL‐28A/IFN‐&lgr;2 were increased in multisensitized children and correlated with IgE levels to dust mite, ryegrass, and fungi but not cat, ragweed, or food sources. Additionally, levels of IL‐5, but no other cytokine, increased with age and correlated with eosinophil numbers in BAL fluid and blood. Both plasmacytoid and IgE+Fc&egr;RI+ myeloid dendritic cells were present in BAL fluid. Conclusions: The lower airways of children with severe asthma display a dominant TH1 signature and atypical cytokine profiles that link to allergic status. Our findings deviate from established paradigms and warrant further assessment of the pathogenicity of TH1 cells in patients with severe asthma.

Risk factors for acute asthma in tropical America: a case–control study in the City of Esmeraldas, Ecuador

Despite the high asthma rates described in Latin America, asthma risk factors in poor urban settings are not well established. We investigated risk factors for acute asthma among Ecuadorian children.

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

IgE to the Mammalian Oligosaccharide Galactose-α-1,3-Galactose Is Associated With Increased Atheroma Volume and Plaques With Unstable Characteristics—Brief Report

Objective— Emerging evidence suggests a link between coronary artery disease and type 2 immunity. We sought to test the hypothesis that IgE sensitization to the mammalian oligosaccharide galactose-&agr;-1,3-galactose (&agr;-Gal)—the target allergen of delayed anaphylaxis to red meat—is associated with coronary artery disease. Approach and Results— Total IgE and specific IgE to &agr;-Gal were assayed on sera from 118 subjects who presented for cardiac catheterization and underwent intravascular ultrasound. IgE to &agr;-Gal was detected in 26%, and atheroma burden was higher in sensitized subjects (P=0.02). Because &agr;-Gal sensitization relates to an environmental exposure that could be a risk factor for early-onset coronary artery disease (ie, tick bites), we age stratified the cohort. In subjects ⩽65 years of age, the strength of the association with atheroma burden was stronger (P<0.001), and plaques in the sensitized group had less stable features based on intravascular ultrasound. To address the specificity of the association with IgE to &agr;-Gal, IgE to inhalants and peanut were assayed and were not associated with coronary artery disease. Total IgE and &agr;-Gal–specific IgE were strongly associated with each other, but the strength of the relationship with atheroma burden was stronger for &agr;-Gal–specific IgE. This association was significant when adjusted for sex, diabetes mellitus, hypertension, statin use, and total IgE (regression coefficient, 12.2; SE, 5.2; P=0.02). Conclusions— Increased atheroma burden and plaques with more unstable features were associated with IgE to &agr;-Gal—an effect most pronounced in subjects ⩽65 years of age. IgE sensitization to &agr;-Gal may represent a novel, and potentially modifiable, risk factor for coronary atherosclerosis.

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